How to use Circuit Notebook

1. Getting started

Open the app: the projects page lists your projects. Create one (New project: a blank sheet, the example, or one of four starter circuits — an LED and its resistor, a voltage divider, an RC low-pass filter, an Arduino lighting an LED — drawn on the sheet for you), import a .olg file, or open the example project to look around: a plant watering station around an Arduino Nano, with its block diagram, a table of measurements, a task board, waveforms and an animated presentation (a switch closes, a current flows). The homepage opens it too: click its big picture. The example opens on its title slide: the small chip at the bottom right of the page says which slide you are on and goes to the next one; F shows the whole sheet.

On your first empty projects, a small First steps card sits on the page: place a part (A, or the library), drag a wire from one pin to another, present (F5). It goes with its cross or with the first thing you draw, and meanwhile the library opens on its Templates tab, whose starter circuits give a first drawing in one click; once the card is gone, the library is back on its parts.

Each card shows the main sheet drawn small. Change cover… (in the card's menu ⋯, in the editor's project menu, the small arrow next to its name, or in the right panel when nothing is selected) puts a picture on it instead (a file, one you paste or one already in the project, framed 16:10), or draws another sheet of the project; Back to the drawing undoes it. A shared project's cover is changed by its editors and seen by everyone who has the project.

Rename a project in the card's menu ⋯, in the editor's project menu (Rename…), or by writing in its name at the top of the editor. A shared project is renamed by its editors and its owner; the others see its name but cannot change it.

You do not need an account. Without one, projects are saved in your browser, as you go, and the chip This browser only at the top of the editor reminds you (the button Create an account next to it makes one in a minute): clearing the browser's data deletes them, so keep a copy of important ones (Export → Project file). With an account, projects can also live on the server, so you find them on any computer and can share them (see Your account).

To learn with ready-made projects, the Academy page lists short explanations of electronics (the buck converter, and more to come): each one opens in the app with its cheat sheet and its animated presentation. Share a lesson with a link such as the buck converter on Instagram: it centers and highlights the lesson, even when a search would hide it.

The Playbook (the Play button of the projects page) teaches electronics one page at a time. Its Sheets and Labs tabs, like the Calculators page, open on an atlas: every sheet, lab and calculator on one sheet of graph paper, in eight families (Basics, Capacitors & coils, Semiconductors…), each joined to the ones that go with it (the LED sheet to the LED lab and to the LED resistor calculator). Point at a bubble to light its neighbours, click it to open it, drag it to move it: its links stretch and the others follow. Scroll or pinch to zoom, drag the paper to move around, click a family to fly to it; on the keyboard, + and − zoom and the arrows move the paper. Type in Find to light what matches (Enter opens the first); the chips bring the sheets, the labs or the calculators forward, show a family, or only the free or the Premium ones. List says the same in a list, for the keyboard, a screen reader and a phone.

• Top bar: back to the projects, the project name and where you are in its sheets, US / EU symbols, undo / redo, the View menu (the grid, the animations, the sounds: soft and quiet, on by default; the two panels; and the theme: lab notebook, whiteboard, blackboard, slate, each with a preview), the ? menu (shortcuts and tips, the shortcuts to change, what's new, this manual), Present and Export.
• Tool rail (far left), in three groups: Select & move (select, pan, comments), Circuit (wire, signal line, hierarchical block, sheet port, net label, animated current) and Notes & more (text, pencil, eraser, shapes, line / arrow, sticky note, frame). The Insert button at the bottom holds the tools you need now and then: image, link button, waveform, timing diagram, table, task board, stamp. Hover a tool a moment: a card says what it is for, with a small drawing and its key.
• Left panel: the library of parts, your templates, the comments and the sheets.
• Right panel: the properties of what is selected. With nothing selected: the name of the sheet, whether it goes in the presentation and the PDF, and the Drawing style of the project (folded: open it to change the line thickness or the bridges).
• Status bar (bottom): the gesture of the tool in hand, in one line (it lights up the first few times you change tool), what the sheet holds (its parts, wires, blocks and ports), where the pointer is and the zoom.

Moving around: the mouse wheel moves the view (Shift + wheel sideways), Ctrl + wheel or a pinch zooms, and you can also drag with the middle button or with Space held down. F fits the drawing to the part of the screen it can be seen in, 0 goes back to 100 %. Both side panels can be resized by their edge, or hidden (Ctrl \, Ctrl Shift \).

Zoomed out, the sheet reads like a map that only names the streets up close: the names of pins go first, then the references and values of parts, net labels, port names, block subtitles and small texts. Frame names and block titles stay readable (they grow, never past their frame or block), and junction dots stay visible. Further out, the grid changes scale and the link, hidden and animation badges make way. Zoom in and everything comes back.

2. Drawing a schematic

The library is folded by domain (Electronics, Control, Graphs for axes, Other for your own) and by category: open what you need, it stays open. Or search it with your own words (arduino, 12 V source, op-amp, 10k, RC filter…): a part whose name has the word comes before one that only has it as a keyword, and Enter takes the best match. Everyday words work too (source, generator, battery, MCU, board, a value like 5V or 100nF, one letter like R or C). A whole circuit that answers the search (RC filter, divider, LED…) shows above the parts: click it to drop it on the page; so does a graph (bode, timing, chronogram). A part number (2N2222, BC557, 1N4148, LM317, IRLZ44N, 74HC00, CD4011, ACS712…) finds its symbol: picked, it comes as that part (a PNP for a BC557, a NAND gate for a 74HC00) with its number written on it; a number never makes a part of its own. French words work as well as English ones (contacteur, bornier, voyant, fin de course). Hover a tile: its name, and for the industrial parts and the modules, what they are for. A opens the quick add box. Click a part, then click on the page to place it; it stays in your hand to place more, Esc stops. The symbol gallery shows every part, in US and IEC drawings.

• R rotates, Shift R the other way, X / Y mirror.
• Any angle, any size: a selected part has a round handle that turns it around its origin (Shift: steps of 15°; it sticks to the quarter turns, which keep the pins on the grid), and corners that make it bigger or smaller (it sticks to ×1.5, ×2, ×3…; Alt: any size). The wires on its pins follow. Size and Angle are in the right panel too.
• The right panel sets the reference (R1…), the value (LaTeX works: $R_{load}$; a bare number gets the unit of the part on the sheet: 10k on a resistor shows 10kΩ, 100n on a capacitor 100nF, what you typed is kept), and the options of the part: channel and body diode of a MOSFET, polarity dots and secondaries of a transformer, position of a switch, size…
• Labels: drag the reference and the value of a part to put them elsewhere; they follow the part when it moves or turns. Labels back in place (right panel) puts them back.
• US / EU in the top bar switches every symbol between US drawings (IEEE 315 / ANSI, the default of a new project) and European ones (IEC 60617); one part can also keep its own standard. Your last choice is remembered in this browser: new projects start with it.
• A transformer can also be drawn winding by winding (Transformer winding): put the primary and the secondaries where they belong, and give them the same reference.

A clear schematic

Ten rules that make a schematic easy to read, and to check:

1. The signal goes from left to right: inputs on the left, outputs on the right. It reads like a sentence, the way the signal travels.
2. Supplies at the top, ground at the bottom. Voltages read from high to low, so the current goes down the page.
3. Parts on the grid, two squares or more apart. Wires meet the pins exactly, and every label has room.
4. Every part has its reference and its value with the unit: R1 10 kΩ, C2 100 nF. A value without a unit is a guess; the reference ties the drawing to the list of parts.
5. Wires run straight, horizontal or vertical, and never through a part. Each wire is easy to follow with the eye.
6. A net label instead of a long wire, or of a wire that would cross many others. Two labels with the same name are connected: the page stays clear.
7. A dot where three wires meet; never four wires in one point: make two T junctions. Four wires in a point look like two wires crossing, which do not connect.
8. One ground symbol where it is needed, rather than a long ground wire. All the ground symbols are one net.
9. A big circuit is split into hierarchical blocks, one function each (supply, MCU, filter). Each sheet fits a screen; the top sheet shows how the parts talk to each other.
10. A short text beside what needs it: the formula, the role of a part, a cut-off frequency. A schematic that says why is one people can check.

3. Wires and connections

• Draw a wire: point at the end of a pin. It lights up and the pointer turns into a small wire (it reaches about 10 pixels around the end, at any zoom; the part itself moves by its body). Drag from there and let go on another pin or on a wire: the wire is done. Or click the pin, click to add corners, and click a pin or a wire to finish (or double-click). W gives the wire tool. / flips the bend while drawing.
• The wire finds its own way with square corners: it keeps off the ends of the other pins and off the wires already there (running over them would join them), and goes around the parts. Let go on the body of a part or a block, away from its pins, and the status bar says why nothing joined. Between two points already connected, no second wire is added: the status bar says so.
• A part whose two pins end up on the same net (a resistor with a wire from one end to the other) gets a red ring, and the status bar says R1 is shorted: click it to select the part.
• Signal lines (Shift W) are wires with an arrow, for block diagrams made of the blocks of the library (Control: gains, sums, transfer functions, integrators; a name typed in a block, such as LoRa radio, is written as text, a formula as maths): they join their pins like wires. Dragged from a pin of one of these blocks, with the select tool, a signal line starts. For the diagram of a system (Sensor → MCU → LoRa radio), take the plain Block: its name is ordinary text, and the right panel sets its size and its number of inputs and outputs. For a diagram of boxes drawn with the shape tool, use Line / arrow (Shift L, see Flowcharts): its arrows hold on to the shapes and find their own way around them.
• Pull an end: select a wire or a signal line; a small square sits on each of its ends. Drag one to make the wire longer or shorter, or to take it off its pin: it lets go of what it was on and joins the pin, the point of a shape or the wire you drop it on (a blue ring shows where). What is connected along the wire stays on it, and its last corners are laid again with square corners, clear of the other pins and of the parts.
• A junction dot appears by itself where three or more connections meet. Wires that simply cross are not connected: the horizontal one jumps over the other with a small bridge. To draw plain crossings, untick Bridges where wires cross (right panel, with nothing selected: Drawing style).
• Moving: drag a part or a wire, and what is attached follows. A wire end on a part that stays keeps hold of its pin (the wire stretches, with square corners); a wire end teeing into another wire slides along it, with its junction dot; net labels stay on their wire.
• Drop on a wire: place or drag a part, or a block, so that its two pins land on a wire, and let go: the piece of wire between them goes and the part takes its place. A loose wire end right beside a pin joins it. Green rings show it while you drag; Ctrl Z puts the wire back. Nothing is cut if another wire tees in between the pins.
• One piece: a selected wire has a small bar in the middle of each piece (cut at the junctions on it): drag it to move that piece alone. Click the wire again to pick the piece under the pointer, and press Delete to remove only that piece.
• Net labels (L): two labels with the same name are connected, even without a wire between them — also across sheets, through the block's ports.
• Wires on shapes: shapes, texts, sticky notes, images, tables, task boards and frames have 16 connection points: the corners, the middle of each side, and a quarter of the way along it from each end. With the wire tool over one, they show; a wire started or ended there holds on and follows when you move or resize it, or change its text. They join no electrical net (no junction dot).
• Those points are often off the grid (the middle of a side), and so is the wire that starts there. A click near a wire lands exactly on it, even off the grid: a wire branched off it gets its junction dot, a net label names it.

4. Sheets and blocks

A block (B) is a whole sheet shown as a box: the controller of a converter, a gate driver… Double-click it (or Enter) to open its sheet; U or Esc goes back up. Inside, sheet ports (P) become the pins of the block. Each one sits on an edge of the block (Edge of the block, or turn it with R, mirror it with X / Y) and points the same way inside the sheet; its direction only changes its arrow. The pins spread out along their edge by themselves; drag the name of a pin to put it elsewhere on the edges (Spread the pins again puts them all back). The wires on the block follow its pins. Ctrl Shift B moves a selection into a new block. The breadcrumbs at the top show where you are, and the Sheets tab lists them all. There, New sheet adds a sheet to the project, the + of a sheet adds one inside it, the bin deletes a sheet with the sheets inside it (Ctrl Z brings them back), and a double-click on a name renames it; each sheet is also a block on the sheet above it. A sheet can be left out of the presentation or of the PDF (its properties, with nothing selected).

A block can have a subtitle under its title (48 V → 12 V, a formula…) and an illustration in its middle: a symbol of the library, a shape or an image of yours (right panel, Illustration). The title and the subtitle then go to the top. Its title takes a font (LaTeX or handwriting), a size, bold, italic and a colour (right panel, Text); a title too long for the block gets smaller to fit in it. Hand-drawn draws the block with a pencil.

5. Text and LaTeX

Anything between dollars is LaTeX: $\Delta i_L = \frac{V}{L}\,t$. It works in texts (T), labels, notes, shapes, arrows, values, port names and waveform labels. Double-click something (or F2) to edit its text in place. The name of a new block, port or net label is written the same way, right where it is drawn (what is proposed is selected: type over it). Zoomed far out, where the writing would be too small, a small card above the element says what you are naming.

Writing a text is like writing on paper: with the text tool (T), a click and you type right there, in the text's own font, size and colour, with nothing around it. With the select tool, a double-click on an empty spot (inside a frame too) does the same. Enter starts a new line; Esc or a click elsewhere ends it and keeps it (Ctrl Z takes it back). A text left empty leaves nothing, and a text emptied is removed. A click makes a text that grows as you type; a box drawn with the text tool sets the width it wraps at, and the two small handles on the sides of a selected text change it. A formula alone (in a text, or alone on its line) is drawn large, as in a textbook.

Bold and italic words: write **bold** and *italic*, the stars touching the words, in a text, a sticky note, a shape or on an arrow. The stars are not drawn; R* or a * b stay as they are. A dollar sign that is not a formula is written \$ (\$5).

Paste text (Ctrl V) from ChatGPT or a web page: it becomes a text near the mouse pointer, in a free place of the view (never over a part, nor under a panel), bold words, bullets and formulas kept. ChatGPT's \( … \) become $…$, its \[ … \] and $$…$$ a formula alone on its line, and prices like $5 stay dollars. A long text wraps, and one Ctrl Z takes it back. A link alone becomes a link button named after its site. Pasted while you write a text, a note or a name, it goes at the caret, the same way (a name stays on one line).

The math bar helps: $…$ (or Ctrl M) puts dollars around the selection or the line, and the buttons insert a fraction, an exponent, an index, a root, a bar, a matrix, Greek letters and symbols (⋯ for more: matrices in parentheses or brackets, 3×3, a determinant, a column vector, systems with {, equations aligned on =). Under it, the formula as it will be drawn. Pressing the index button right after V gives $V_{n}$, ready to type over. The bar is there in every field of the right panel that takes LaTeX (block titles, values, port and net names, labels of arrows and graphs): it opens under the field while you type in it. A text can have a frame around it (box, rounded, double).

The Text section of the right panel styles any text, and the text written in a shape, a sticky note or on an arrow: LaTeX or handwritten font, size, bold, italic, underline, left / centre / right (and top / middle / bottom in a shape), and its own colour. Select several things to change them together. The options of the text tool (T) set the font, size and weight of the next texts, and keep them for next time. A line with a formula stays in the LaTeX font.

Defaults for new elements (View menu, or the last button of the options of the text, shape and line tools): the font of new texts (and of what you write in new shapes, arrows, sticky notes, tables and task boards), their size and weight, hand-drawn shapes and their fill, hand-drawn lines and arrows, their ends (line, arrow, double arrow, dashed) and their route (right angles or straight), the ink of new wires and of new signal lines, the arrows and dashes of signal lines, the colour of new sticky notes. A small sheet shows the result. They are yours, saved in the browser for all your projects; what is already drawn keeps its look. The thickness of wires and drawings belongs to the project (Drawing style). Use as default, under the settings of a selected text, shape, arrow, wire, signal line or sticky note, makes the new ones look like it.

6. Whiteboard and flowcharts

• Pencil (D) and eraser (E): freehand notes. With a stylus, its pressure makes the line thicker or thinner; with a mouse or a finger, the speed of your hand does (slow is pressed, quick is light), and both ends taper. A line looks the same whatever the zoom you draw it at. The pen menu of the pencil (left of its sizes) picks how the line is laid: ballpoint, highlighter, chalk (grainy and even, white on a dark board and black on paper, with a little powder around it and dust falling as you draw), and the pens of Customize you own. The colour stays yours, next to it. The right panel changes the pen of a stroke afterwards.
• Stamp (Shift S, or Insert): a rubber stamp, like in a design office. Pick its words in the bar above the canvas (CHECKED, APPROVED, DRAFT, FOR REVIEW, REV. B… or your own, sixteen letters at most), the date and your initials, its rubber and its ink, then click: it is pressed there, a little askew, its ink uneven like real ink. Move it, turn it with its round handle, resize it; double-click it to change its words in the right panel. It is part of the drawing: everyone working on the project sees it, and the exports keep it (SVG, PNG, PDF and LaTeX).
• Shapes (S): the menu of the tool sorts them in two groups, Basic (rectangle, rounded rectangle, ellipse, diamond, triangle, parallelogram, hexagon…) and Flowchart. They hold a text (double-click, Enter for a new line, Ctrl Enter to finish). Hand-drawn gives them a pencil look and writes their text by hand. Their fill, and the fill of a text, can be plain, laid in pencil (strokes of coloured pencil) or with a highlighter (felt-pen passes behind the words, a little wider than them, their overlaps darker): Style in the right panel. Shift while drawing keeps a square or a circle.
• Turn and flip: drag the round handle above a selected shape, image, graph, sticky note, text, button or straight line to turn it to any angle (Shift: steps of 15°), or type it in Angle. R turns it by 90° around its own centre, X / Y flip it in place. The text of a shape turns with it but is never upside down; arrows stay on the same side.
• Several things at once: select them (or a group) and one frame goes around them. Its corners make them all bigger or smaller (texts and parts included), its round handle turns them together. With wires in the selection, it turns by quarter turns, so the wires stay square. A pencil stroke alone gets the same frame.
• Lines and arrows (Shift L; its menu: plain line, arrow, double arrow, dashed line, then right angles or straight). A straight line: drag its round middle handle to bend it, the round handle beside it to turn it (around its middle, or around its end attached to a shape). A line with right angles: click one of its segments to pick it, then drag it (or drag the small bar in its middle); the end stays where it is, with a little jog. A selected line gets a soft halo along it. Lines that cross get a small bridge, like wires: the horizontal one jumps (a curve or a hand-drawn line never does: the one crossing it jumps).
• Sticky notes (N; drag for its size, or click for the usual one), images (I, or paste / drop a file).
• Edit an image from its panel. Crop… (or double-click it): move and resize the frame by its 8 handles, or drag outside it to draw a new one; ratios Free, 1:1, 4:3 and 16:9; the part you keep stays at the same place and scale. Remove the background: Plain background takes away the colour around the picture (a tolerance; Inside closed shapes too for a diagram on white), Paper photo keeps only the ink of a photographed page (strength, black ink), AI finds the subject of a photo. The AI runs in your browser: the model (about 46 MB) is downloaded once from Hugging Face and kept by the browser, and your picture is never sent anywhere. Also Corners (rounded), Opacity, a Border (its thickness, its colour in Style), Replace image… and Original size. Ctrl Z undoes each change; the PDF and PNG keep them.
• Frames (Shift F): a named region; they are the slides of the presentation.
• Comments (C): pin a discussion anywhere on the page; drag it to move it.

Flowcharts

Draw an arrow from a shape: with the select tool, hover a shape, a sticky note, an image, a table or a task board: its connection points show. Press on one (a blue ring shows it, on the point or just outside the element; from inside, the element moves as usual) and drag to another element, or anywhere: an arrow is drawn, attached at both ends, in the look of the line tool (its ends and route are in Defaults for new elements). A selected shape keeps its handles: its corners and the middles of its sides resize it.

Start or end a line on a shape: it snaps to one of its 16 connection points (the corners, the middle of each side and a quarter of the way along it), or anywhere along the outline between them (on the grid; Alt: exactly there), and stays attached there, even when the shape moves or grows. With Right angles, it goes around the shapes; drag one of its segments where you want it, and it keeps that place when the shapes move (Automatic route, in its properties, lets the route find its own way again). Give it a label (yes, no…).

Links

Anything can carry a link (right panel → Link): a web page, an online PDF (a datasheet…), or another sheet of the project. Ctrl + click follows it in the editor; a click follows it in the presentation and in the PDF. A link button (K) is a button made for that.

Tables

The table tool (Shift T) puts a 3 × 3 table where you click, its first row a header (bold, on a light tint), and you write in its first cell straight away. A cell holds text and LaTeX ($R_1 = 10\,k\Omega$); its row grows with its text, which wraps in the column.

• Writing: double-click a cell. Tab goes to the next cell (after the last one, a new row), Shift Tab to the one before, Enter to the one below, Shift Enter starts a new line in the cell, Esc ends.
• Pasting a table: copy cells in Excel, Google Sheets or LibreOffice, a table of a web page or of a chat (ChatGPT…), or a markdown table, and paste it on the sheet: it becomes a table near the pointer, in a free place of the view (the maths of a chat come as LaTeX). A picture pasted on the sheet lands the same way. Copy the table alone: with words around it, as a whole answer of a chat, it is pasted as a text. Pasted into a cell being written in, the cells fill the table from there, and it grows to hold them. A .csv file dropped on the sheet gives a table too.
• Cells, one by one: a click on a cell picks that cell, not the whole table, as in a spreadsheet. Shift + click picks the rectangle from it, Ctrl + click one more cell (or one less), a drag over the cells a rectangle; the strips that appear along the top and the left of the table pick whole columns and rows. The arrows move the cell picked (Shift: further cells), a key typed writes in it, Enter or F2 edits it, Delete empties the cells, Ctrl C / Ctrl V copy and paste them (with a spreadsheet too), Esc goes back to the whole table.
• Moving it: drag its border (the pointer becomes a cross of arrows), or click its border to select it whole: then a drag from anywhere moves it, and the panel works on all its cells.
• The look of each cell: the right panel gives the cells picked (all of them when the table is selected whole) a text, a paper, bold or italic, a colour, their place in the row and their alignment; the width and the alignment of a column apply to every column the cells are in. It adds rows and columns around them, deletes them, and sets the number of rows and columns. Drag the small handles on top of the column borders to make a column wider or narrower. The Text section sets the font and size of the whole table, Style its lines.
• Out of the sheet: Copy for Excel puts the cells in the clipboard for a spreadsheet or a document; Copy as LaTeX gives a tabular for a report. The CircuiTikZ export writes it as a tabular too.

Task boards

A task board (a kanban, Shift K) sits on the sheet like a sticky note: three columns, To do, Doing and Done, and you name the board straight away. It belongs to the sheet: whoever may edit the sheet changes it, and Ctrl Z takes a change back.

• Cards: + Add a card at the foot of a column gives a card to write in (Enter keeps it, Ctrl Enter keeps it and writes the next one under it, Shift Enter starts a new line; a card left empty goes away). Letters typed on a picked card go at the end of its text. Drag a card to another column or to another place in its own: the column it would land in lights up, a line shows where. Double-click a card, the heading of a column or the title to rewrite it. Cards take LaTeX too. A click on a card picks that card only; Ctrl + click picks more, and the panel gives them all to someone, ticks them, moves or deletes them (Delete). The board itself moves by its border, its title or the room between its cards.
• Who does what: click a card and tick, in the right panel, the people doing it: you, the people of the project (its members, its owner, its teams) and the people here now. Their initials show on the card in their colour, the same for everyone and in the exports. Done puts a tick on it. In a project kept in this browser, there is only you: Share the project, under the names, puts it on the server (or first creates your account) so that your group joins it.
• Your tasks: when cards of the sheet are given to you, the status bar says N tasks for you; a click shows the first one.
• Columns: rename, add or delete them in the panel (the cards of a deleted column go to the one beside it). Drag the handle on the right side of the board to make it wider. + Add a card is never drawn in the presentation nor in the exports; the CircuiTikZ export frames each column and writes each card.

7. Waveforms

The waveform tool (O) draws oscillograms and chronograms. Signals are sorted by type: periodic (sine, square or PWM with levels 0–1 or ±1, triangle to sawtooth, half and full wave rectified), power (DC with ripple), responses (first and second order steps, exponential, ramp, damped sine) and other (DC level, your own points). Start from a preset (sorted the same way: basics, power electronics, control), then set each curve: amplitude, offset, periods, phase, duty cycle, colour, dashes and label (LaTeX). Stacked puts one curve per band, like a chronogram; overlay puts them on one axis, and their labels spread apart when the curves end at the same place.

• The graph editor: double-click a graph, or Edit graph… in the right panel. A large preview on the left, the graph and its curves on the right; every change shows at once and Ctrl Z undoes it. Custom points are typed as 0,0; 0.5,1; 1,0 (or one pair per line).
• Bode plots: magnitude (dB) and phase (°) against ω on a log scale, with the asymptotes if you want them. A curve is a system: first order, second order (ζ and ω_n), integrator, lead-lag, or your own poles and zeros, with its gain.
• Poles and zeros: the same systems in the s-plane (stable half shaded) or the z-plane (with the unit circle): × for the poles, ○ for the zeros.
• In the presentation, a curve can change on a click: its phase scrolls, its damping drops, its duty cycle grows (see Animations).

Timing diagrams

The timing diagram tool (Shift O, under Insert) draws digital signals cycle by cycle, as in a datasheet: clocks, bits at 0 or 1, a bus with its values in hexagons, X for unknown (hatched), Z for high impedance (a line in the middle), gaps in time, groups of signals and the times between two edges. Its options choose what a click puts on the sheet: a clock and data, an SPI frame (mode 0), an I²C start and stop, a UART 8N1 byte, or a clock alone.

• Edit it on the sheet: click the diagram to select it, then click a cycle to flip it (a clock stops or starts again) and drag along a signal to paint the cycles the same. On a bus, drag over cycles to write a value: type it at once (Tab goes to the next value). Double-click a value, a name or a label to change it.
• Pick cycles with Shift + click, then press 0, 1, X, Z, P (clock), = (a value) or | (a gap), or use the buttons of the panel; the arrows move.
• The panel: the number of cycles and their width (or drag the handle on the right side), the signals (rename, move up or down, delete, add a bit, a clock, a bus or a space), a group for the signals picked, a tint for the values, a title, a caption, the cycle numbers and a template.
• Time arrows: Time arrow in the panel rings the edges; click one, then another, and type the label (t_SU, 10 ns). The arrow goes on a row of its own, with dotted lines up to both edges. Its shape and label change in the panel.
• WaveDrom: paste WaveJSON on the sheet (Ctrl V), or write it in Paste WaveJSON (tool options) and see the diagram as you type. Copy as WaveJSON and Edit as WaveJSON (panel) go the other way. Waves (p n 0 1 l h x z = 2-9 . | u d), data, groups, period, phase, node and edge arrows, head and foot are read.
• In the PDF, SVG and PNG it looks the same; CircuiTikZ draws it with plain TikZ. In the presentation, an entrance draws it from left to right.

8. Arrange and style

• The right panel shows the settings of what is selected, then the same sections for everything, folded: Arrange, Text, Style, Link, Visibility and Animation (Presentation for a frame). A folded heading shows its values at a glance (font and size, ink and fill…). Click it to open the section; it stays open for the next selections, until you fold it again.
• A number (a size, an angle, a duration…) is set with the mouse too: drag its field left or right (Shift: faster), or turn the wheel while typing in it; ↑ ↓ step it as well. A click types in it.
• Select a zone: drag on the empty page. Drawn left to right, the zone takes what lies fully inside it; right to left, whatever it touches. A frame is a background: it is taken only when the zone holds all of it, or (right to left) crosses its border or its name tab, so a zone drawn inside a slide takes what is on it, not the slide.
• Copy and paste (Ctrl C, Ctrl X, Ctrl V): what you paste lands under the mouse pointer, parts and wires still on the grid. Paste again without moving it and each copy steps a little down and right; with the pointer off the sheet, the copy goes next to the original. Ctrl D duplicates next to the original.
• Alignment guides: while you drag shapes, blocks, notes or parts, blue construction lines show where an edge (dashed) or the centre (a chain line, like the axis of a drawing) lines up with something else on the screen, with a small cross on each box, and the move sticks to it. Shapes line up even off the grid; parts stay on the grid. Hold Alt to move without the guides.
• Group (Ctrl G, Alt + click selects inside a group), align and distribute several things (Arrange).
• Arrange: the Angle of what turns, quarter turns and mirrors, then the order: to the front, one step forward (Ctrl ]), one step backward (Ctrl [), to the back (a background).
• Style: ink, fill, stroke and dash (on the blackboard, the fills turn dark); for shapes and texts, how the fill is laid: Plain, Pencil or Highlighter, the same in the exports (CircuiTikZ draws hatching or a translucent fill). Visibility → Lock position so it does not move.
• Line thickness of the project: with nothing selected, the right panel's Drawing style sets the thickness of the wires, of the parts (components, blocks, ports, net labels) and of the drawings (shapes, arrows, text frames, waveforms). Everything left on Default follows it, in the exports too and for everyone on the project; a thickness chosen for one element wins. Junction dots grow with thick wires.
• Shadows: tick Shadows in the same Drawing style for a soft drop shadow, as in draw.io, under the shapes, sticky notes, framed texts (or texts on a fill), images, link buttons, blocks, tables and task boards. Wires, arrows, parts, pencil strokes and plain texts get none. It is a setting of the project: everyone on it sees it, in the presentation and in the exports (PDF, SVG, PNG; a drop shadow in CircuiTikZ for the filled boxes). Darker and fainter on the blackboard and slate themes.
• Visibility → Show in: untick Presentation or Export to leave something out (draft notes, hints for you). The eye icon on the page reminds you of it.
• A clean page: untick Visibility marks in Drawing style to hide those eye icons, and Currents while editing to hide the animated currents while you draw. Only the editor changes: what was left out stays left out, the currents still play in the presentation (the exports never draw them), and a selected current still shows. Like the shadows, it is a setting of the project, for everyone on it.

9. Your own parts and templates

• New symbol (top of the library) opens the symbol editor: draw it with lines (L), polylines (P: click each point, double-click to finish, click the first point to close it), rectangles (B), circles (C) and texts (T), place its pins (N), pick its domain and its category (one of the list, or a new one: New domain… makes a domain of your own in the library), and it joins your library. Or start from a built-in symbol, sorted by domain.
• With the select tool (V): Shift+click or a zone dragged on the grid selects several things; drag them, resize them from the corners of their frame (Shift keeps the proportions), turn them with its round handle; R, X / Y, Ctrl D to duplicate, Ctrl C / Ctrl V to paste under the mouse pointer (pins on the grid), the arrows to nudge. The wheel zooms, Space+drag moves the view. Ctrl Z / Ctrl Y undo and redo; Esc drops the selection, and closing asks before losing a drawing. Customize symbol… in the properties of a part starts from that one.
• Pin names: give a pin a name (Pin name) and it is drawn beside it, inside the body: no text to add. For one pin or all the selected ones, choose the side (inside, or outside above the pin), along or across the pin, a shift, its number and a dot at its end (filled or hollow). Texts turn with R (around their point) or their Angle, and align left, centre or right. Hold Alt while you draw, move or resize to place things off the grid (a small square right on a pin); pins stay on the grid.
• On the sheet, a turned part turns its pin names and its words with it, always readable: never upside down, they stay on their side of the pin. Formulas, single signs (the V of a voltmeter) and the reference and value stay upright.
• Symbols of a shared project: each one keeps its author. Under Save in, choose what the others may do with yours: Can place it (the default) or Can also change it. Its author and the project owner can always change it. Someone else's symbol opens read only, with Duplicate to edit to carry on with a copy of your own. The library shows who made a symbol of someone else (by Tom), so two symbols with the same name stay apart, and the search finds a symbol by its author's name too.
• Starter circuits: the Templates tab starts with five circuits to begin from: a voltage divider, an RC low-pass filter, an LED and its resistor, a non-inverting amplifier and an Arduino lighting an LED. Click one to drop it in the middle of the view (or drag it onto the page), then change its values. A second copy gets references of its own (R3, R4…). Four of them are also offered when you create a project (New project, and the empty projects page): the project starts with the circuit drawn.
• Boards: Electronics › Microcontroller boards has the Arduino Uno, the Arduino Nano and the ESP32 DevKit, with the names of their pins as printed on the board, and a generic microcontroller (VDD, VSS, reset, clock, the usual peripherals). Modules & sensors has the modules of a maker's kit, their pins named as printed on them: DHT22, relay module, HC-SR04, L298N, OLED SSD1306, BME280, MOSFET module, LM2596 step-down module, servo, HC-05, PIR HC-SR501, MPU-6050, LCD 16×2 I2C, DS18B20, WS2812B, LM35 / TMP36. The NE555, the ULN2003A and the L293D are in Analog ICs, the 74HC595 in Logic gates, their pins as on the chip. They are generic ICs: the right panel changes their pins and their names.
• Motor control: Electronics › Industrial control has what the power and control circuits of a motor are drawn with: the contactor (its coil, its main contacts, its auxiliary contacts), the thermal overload relay and its contact, the circuit breaker and the motor circuit breaker, the disconnector and the fuse disconnector, the indicator lamp and the terminal block. The push button, the emergency stop and the limit switch are in Switches & protection, the three-phase motor in Machines. Each is drawn as IEC 60617 has it in EU symbols, and as a US ladder diagram has it (NEMA, JIC) in US symbols. Power devices stand upright with 1 to 4 poles, on the phases of the motor; control devices lie left to right, like a rung (press R to stand them up). They write their terminal numbers (13-14, 95-96, A1-A2, U1 V1 W1), and their names start as an electrician writes them: KM1, F1, Q1, S1, H1, X1. A contact belongs to the coil that has the same name: rename it KM1.
• Templates: select a piece of circuit (a half-bridge with its driver, a filter…) and save it as a template, in a category of your choice. Drop it in any project from the Templates tab: it stays connected. Categories fold; drag a template onto another category to move it, rename a category with its pencil, delete it with its bin.
• Sort your own symbols: drag one onto a domain or a category of the list to move it there. A domain or a category of your own can be deleted (the bin on its header): keep its symbols (in Other or Custom), or delete them with it. Projects that use one of them keep their copy. Built-in symbols, and those of a project shared with you, stay where they are.
• Your symbols and templates are kept in your browser; with an account they follow you to every computer. They are saved in two files (.olglib): the arrow at the top of the library exports your symbols, Export templates (Templates tab) your templates. Import, in either tab, adds what a file holds.

10. Presenting

Present (F5) shows the frames of the main sheet as slides; a sheet without frames is one slide. Click, → or Space goes on, ← goes back, Esc returns to the editor. Shift F5 (or Shift-click on Present) starts on the sheet you are on instead. A sheet left out of the presentation is skipped: the presentation starts on the first sheet that has something to show.

Each sheet is a presentation of its own: the slides of a block are not added to those of the sheet around it. Click the block to go in and through its slides; after its last slide, the next click takes you back out, where you were. So a talk can go down into the details only when the audience asks.

Slides and transitions

Slides follow the reading order of the frames. Select a frame to set its place: Slide 2 of 5 with ‹ › to show it earlier or later (the numbers appear next to the frames while one is selected; ↺ goes back to reading order). Choose its transition there too: the camera glides (default), fade, slide in, slide up, zoom through, blur or cut; fast, normal or slow.

A sheet with several frames opens on its first slide, readable. While the view is on a slide, a small chip at the bottom right of the page says which one (Slide 2 / 6) and goes to the next; F shows the whole sheet again.

Overview, then zooms

Draw a frame around the whole drawing, then smaller frames inside it: the camera flies from the overview into each part, and back. Each element plays its animations on the smallest frame around it: the overview shows the drawing, each zoom builds up its own part. Animated currents keep flowing while the camera moves.

During the talk

• Click a block (or a button linking to a sheet) to dive into its sheet; Backspace, the ↰ button, a link back, or a click after its last slide comes back where you were, at the same click.
• L laser pointer, P pen, C clears the pen on this slide. B brings up a blackboard instead of the slide: draw on it in chalk with either mouse button, point with the laser, wipe it with C. The slides do not move while it is up; B or its button (red while it is up) takes it away, and your chalk is still there next time.
• Shift B (or the button with two columns) puts the blackboard beside the slide: the slide takes one half of the screen, the board the other, and the slides still move. It is the same board, so what you write beside the slide is there when it covers the slide. Those who follow you see the same.
• Your pen notes are not saved unless you ask. When you end a presentation where the pen wrote something, it asks: Keep my notes puts the strokes of every slide on the sheet in red pencil, where you drew them, in one step (Ctrl Z takes them away); Download as PNG gives a picture of the slides you wrote on (the only choice when you cannot edit the project); Don’t keep leaves the sheet as it was. The notebook button of the control bar keeps them at once.
• Esc puts away what is on top, one thing at a time: the blackboard, then the pen or the laser, and then ends the presentation.
• Links open in a new tab, and the presentation goes on.
• On a phone or a tablet, tap the left third of the screen to go back one click, anywhere else to go on; a tap also brings back the control bar (a tap where the hidden bar is only brings it back).
• In a shared project, the others see a Join button while you present: they follow your slides on their own screen, with your mouse, your laser and what your pen draws. The pen stays on the slide: it moves with it. People with a view link (no account) see Presentation live: follow the slides.

11. Animations

Select something inside a frame and open Animation at the bottom of the right panel, then Add.

Each animation plays as the slide opens or on click 1, 2, 3…, with a duration and a delay (several on the same click start together; use the delay to play them one after the other). A click plays the next step before going to the next slide; going back undoes the last step. While the Animation section is open, small numbers on the page show on which click things happen, and a selected frame lists its build order. Preview presents that slide right away.

Animated currents

Show a current flowing through the circuit: dots, electrons, charges, arrows, dashes or comets that move along its path, at a speed that follows the current.

• Select the wires (and the parts, like a resistor or a coil) the current goes through, then click Animate a current here in the right panel, or press Shift I. When they make a loop, the current goes round it.
• Or, with nothing selected, press Shift I and click its path point by point, like a wire; click its first point to close a loop, double-click or press Enter to end it.
• Current in amperes: a negative current flows the other way (or use Reverse). Signal: DC, sine, square, triangle (a ripple around an offset), sawtooth, PWM pulses, or a ramp, rise or decay that starts when the current appears.
• What flows, its colour (Style), size, spacing and speed per ampere; Electron flow makes electrons go against the current.
• It runs in the presentation, and in the editor while it is selected. Give it an Appear animation to start it on a click, or Change the current to reverse it. The exports (PDF, PNG, SVG, image) leave it out: still dots would read as part of the drawing. To draw without the currents in the way, untick Currents while editing in Drawing style (nothing selected): only a selected one still shows.

12. Export and import

• PDF: every sheet, one page each, with bookmarks; blocks and links are clickable.
• SVG and PNG of the current sheet; Copy as image (or Shift C) to paste straight into a report, a slide or a chat.
• CircuiTikZ: LaTeX code of the sheet, to paste in your report, with US or European symbols like your project. The usual parts are real CircuiTikZ components, turned and mirrored as on the sheet, so you can edit the code by hand: resistors, capacitors, coils, diodes, sources, switches, meters, thyristors and TRIACs carry their name and value (to[R, l=$R_1$, a={$10\,\mathrm{k\Omega}$}]); a thyristor's gate wire starts from (TH1.G). Transistors, op amps, logic gates, transformers, grounds and supply rails are named nodes, and the wires start from their pins: \node[nigfete, bodydiode] (Q1), then (Q1.D) -- …. Sources go from − to +, with voltage dir=RP. A part CircuiTikZ does not have is drawn exactly as on screen, with a comment saying so. It loads hyperref only when the sheet has links.
• KiCad schematic (.kicad_sch): the circuit of the sheet, to draw its PCB in KiCad 7 or later. The parts become the symbols of KiCad's own libraries (a resistor is Device:R, a US one Device:R_US, a transistor Device:Q_NPN_BEC, an op-amp the generic Device:Opamp_Dual), copied into the file so nothing is missing; each keeps its reference, its value, its place, its turn and its mirror, and its wires reach the right pins. A value that names a common part becomes that real part, with its own pins and footprint: a BC547, 2N3904, 2N7000, IRLZ44N, 1N4007, 1N5819, LM358, TL072 or LM7805, among others. Grounds and supply rails are KiCad power symbols (GND, +5V), each with a PWR_FLAG when nothing on the net is a power output, so that the electrical rules check passes. Net labels stay labels. A part KiCad has no symbol for keeps its drawing, its pins named; one drawn as a box (an Arduino, a generic IC) is drawn as KiCad draws its ICs, its unused pins crossed. The file follows the rules of a clean schematic: grounds and rails on a lead of their own, no hook at a pin, references and values beside their part, clear of the wires. A sheet with blocks comes as a .zip: a KiCad project with a sheet per block. Every export is read back the way KiCad reads it and its nets compared with the drawing; the window says so, and lists what has no place in a schematic (notes, images, graphs, tables). In KiCad: assign the footprints the generic parts still lack (Tools → Assign Footprints), then Update PCB from Schematic. Sources and meters are kept off the board: put the connector you will use in their place. (The KiCad symbols come from the KiCad libraries, CC-BY-SA 4.0, free to use in your designs.)
• Project file (.olg): the whole project, to keep or send. Import it from the projects page.
• The preview shows the image you will get, redrawn when you change an option. Choose the colours (cream paper, white, blackboard…) and the background. Image format frames SVG, PNG and Copy as image: Fit the drawing, or Square 1:1 and Portrait 4:5 for a post, Landscape 16:9 for a slide, the drawing in the middle; Margin leaves more or less room. Tick Only the selection to export just what is selected (in KiCad too: a block selected brings its whole sheet); what you left out of the export (Show in) is listed.
• The files take the project's name, accents as plain letters (résistance → resistance, µF → uF). An SVG carries its fonts only when it has text to write: a schematic alone weighs a few kB. The animated currents play in the presentation only: the exports leave them out.

13. Your account

An account is free and optional. Sign in is at the top right of the projects page. The window says what an account gives: your projects online, your team, and the founder price (-50 % on Premium, for life) for every account created before 1.0.

• Create an account with Google or GitHub when the server offers them (no password to remember; the first time, an account with the same verified e-mail is used), or with your name, e-mail and a password: a 6-digit code is sent to your e-mail to check it (have a look in your spam folder).
• After your first export or your first presentation of a project kept in this browser, the app asks once whether to keep it online with a free account. Not now is for good, and the question goes as soon as you sign in.
• Signed in from a project kept in this browser, Keep this project online? puts it on your account in one click (also Share → Upload and share). This browser keeps its copy: on the projects page, its card says Local copy, next to the online one, marked Online (or Shared once someone else has it, or a link or an invitation waits).
• Forgot your password? on the sign-in window sends a code to choose a new one; it signs you out everywhere else.
• The menu of your name: your @username (how friends find you) and your name, Edit my profile, Friends & teams, Sign out, and Delete my account (it tells you what goes away first).
• Edit my profile: choose a picture, then drag and zoom it to frame it in the circle. It shows in your account button, to your friends and teams, to the people of your projects and next to your cursor. Your name and your colour are there too.
• Folders (New folder on the projects page): sort your projects — on the server or in your browser — in folders of any colour, folders inside folders. Drag a project onto a folder, or use Move to folder… in its menu (⋯). Folders are yours only: sorting a shared project changes nothing for the others. Deleting a folder deletes no project: what it held goes up one level.
• During the beta each account keeps a few projects on the server (shown on the projects page); projects in your browser are unlimited. Move to this computer (menu ⋯ of a project) brings one back into your browser.
• My plan (menu of your name) shows what your account keeps on the server and what you use. From version 1.0, Circuit Notebook has a free plan and Premium (see the pricing page); every drawing tool and every export stay free. If Premium stops, nothing is deleted: what goes beyond the free plan becomes read-only until you make room.

14. Working together

• Share (top bar of a project on the server): type an e-mail or a @username, choose Can edit, Can comment, Can view or Can view, no export, then Invite. A @username is added at once; an e-mail address gets a link that works once, for that address only, for 7 days (waiting invitations are listed: cancel one with 🗑). You can also add a friend or a whole team, or create an invite link for One person (used once) or Anyone with the link.
• View link (no account), for a class or a tutor: in Share, choose All sheets or Some sheets, an end date if you want one, and View, no export if they should not download it, then Create a view link and copy it. Whoever opens the link sees the project read only, without an account: zoom, move around, open the sheets and blocks, search for a part, and follow your slides when you present. They never see who is on the project, the comments, or what you hide from the presentation; a hidden sheet is never sent to them. The Share window counts how many times the link was opened and how many people view it now (numbers only). 🗑 turns it off: everyone viewing with it is stopped at once. Only the owner makes view links; the full link is shown when you make it, and this browser remembers it to copy it again.
• Invited? The invitation shows on your projects page (and a number on your name): Join or Decline.
• Can view, no export (for a customer): they look and present, but the export, download, copy and print buttons are off, and the server refuses its downloads. It stops the easy ways, not a screenshot.
• Where the data lives: projects on the server are stored in the EU (Germany, Hetzner), behind Cloudflare. Details in the privacy policy.
• Rights per sheet: give someone more or fewer rights on one sheet, or hide a sheet from them (a lab report where each group sees its own part…).
• Everyone's cursor and selection show live, in their colour. Comments can be answered, resolved and reopened.
• History keeps versions of the project (automatic ones, and the ones you name): look at one, or bring it back. It has a limited room (shown in the window): the oldest automatic versions make way for new ones, and a saved version can be deleted by whoever saved it or by the owner.
• Friends & teams (menu of your name): add friends by @username, gather them in teams, and share with a team in one click.

15. On a phone

On a phone the drawing takes the whole screen. The bar at the bottom opens the tools, the parts, the sheets, the comments and the settings. One finger moves the view (or a part), two fingers zoom. A new sheet opens at 200 %, so a part comes out the size of a fingertip. Tap a part to get its actions: rotate, mirror, copy, edit, delete. With the wire tool, a tap lands on the nearest pin within a fingertip, even if your finger covers it. Presenting works too: tap the left third of the screen to go back, anywhere else to go on, upright or sideways.

16. Words of the notebook

What each tool and each word of the app is for. In the app, rest the pointer on a tool, a part of the library whose name is jargon, a heading of the right panel or a button of the presentation bar (or focus it with Tab; on a phone, hold your finger on it): the same card shows, with the tool's key.

Drawing a schematic

Part

A component of the library, placed with a click; R turns it, X and Y mirror it.

Wire

Connects the pins of parts: drawn from pin to pin, it is an electrical connection.

Junction dot

Shows that wires meeting here are connected (the app draws one where three meet).

Bridges

A hop where two wires cross shows they are not connected (a dot means they are).

Net label

Two wires with the same name are connected, without drawing the wire between them.

Hierarchical block

A box you open: its inside is another sheet, so a big circuit fits on small pages.

Sheet port

A door of the sheet inside a block: it becomes a pin of the block, outside.

Signal line

Carries a signal from block to block in a block diagram, pin to pin.

Generic block G(s)

Stands for any system of a block diagram: write its transfer function inside.

Block

A box named in plain words (Sensor, LoRa radio) for a block diagram of a system.

Drawing on the board

Text / LaTeX

Writes words and formulas on the sheet (a formula goes between dollar signs).

Pencil

Draws freehand, like a pencil on the page, for quick sketches and marks.

Eraser

Rubs out what you drag over: a pencil stroke or a whole element.

Shapes

Rectangles, circles, diamonds and more, for diagrams and flowcharts.

Line / arrow

Joins shapes and notes, or any two points: for flowcharts and sketches.

Sticky note

A square of coloured paper to stick a reminder or a to-do on the sheet.

Image

Puts a photo or a picture on the sheet, to crop it or cut out its background.

Waveform

Signals against time (chronograms), Bode plots and poles, calculated for you.

Timing diagram

Digital signals as in a datasheet: clocks, bits, buses and the times between edges.

Text

Font, size, bold and colour of the words of the selection.

Style

Colour, thickness, dashes and fill of the lines and shapes of the selection.

Shadows

A soft shadow under boxes, notes and images, to lift them off the page.

Organising

Select

Picks what you click or frame, to move it, change it or delete it.

Pan

Slides the sheet under the screen, like moving the paper with your hand.

Comment

Pins a question or a remark to a spot of the sheet, for the people who read it.

Table

Rows and columns for measures or a parts list; paste cells from a spreadsheet.

Task board

Columns of cards (to do, doing, done) to share out the work of a project.

Link button

A button that opens a web page, another sheet or a slide when clicked.

Stamp

A rubber stamp for a sheet: CHECKED, APPROVED, DRAFT, with the date and your initials.

Arrange

Position, size, angle and order of the selection, and lining things up.

Link

Makes the selection clickable: to a web page, another sheet or a slide.

Visibility

Locks the selection in place, or leaves it out of the presentation or the PDF.

Presenting

Frame

A slide: when you present, each frame fills the screen in turn.

Animated current

Shows the current moving along wires when you present, as flowing dots.

Animation

Makes the selection appear, move or change, click by click, when you present.

Laser pointer

A red dot that follows your pointer, to show the audience where to look.

Pen

Writes on the slide during the talk; nothing stays unless you keep your notes.

Keep my notes

Puts what you wrote with the pen on the sheet, in red pencil, for after the talk.

Blackboard

Hides the slide behind a blank board to write on, then brings it back.

Blackboard beside the slide

Puts a board next to the slide, to write without hiding it.

17. Keyboard shortcuts

Press ? in the app for the full list; you can change any of them there (Ctrl is ⌘ on a Mac). The most useful:

18. The beta and help

Circuit Notebook is in open beta, free while it grows, and changes often: see what's new in each version. Found a bug, or missing a symbol? Tell me through the contact form. How your data is handled: the privacy policy.