PyRaspInstruments
The bottom dock holds the code editor and the instruments. Its header has a Code button that collapses the whole dock, a Hide code / Show code button that gives the instruments the full width, and one tab per instrument; the status on the right tracks the program (loading, waiting for the simulation, running, exited, waiting for input).
The instruments watch the running simulation. The plotter, recorder, logic analyzer and bus sniffer show nothing until you press Run; stop the run and their data is cleared when they next reset.
Logic analyzer
The logic analyzer draws GPIO levels against simulated time.
- Channels start as the GPIOs you have actually wired (up to twelve). The checkbox grid lets you add or remove any GPIO from 2 to 27.
- Window sets the visible time span: 1 ms, 10 ms, 100 ms, 1 s or 10 s.
- Trigger arms on a rising or falling edge of one channel. When it fires, the view freezes so you can inspect what happened; Live resumes.
- PWM pins are drawn as a duty/frequency annotation in orange instead of individual edges.
- The bus lane under the traces shows decoded I²C, SPI, UART, 1-Wire, DHT and WS2812 transactions at the moment they happened.
- Click to place cursor A, shift-click for cursor B; the footer reads the time difference and the equivalent frequency.
Clear empties the captured history and cursors. A pin's history keeps the most recent 20,000 edges; the oldest are dropped.
Plotter
The plotter graphs up to sixteen channels against simulated time: any numeric state field of any part, and the voltage on any GPIO. Open Channels, filter the list and tick what you want to watch; each trace gets its own colour and a live legend. The window is 10 seconds, 1 minute or 10 minutes.
Values are sampled twenty times a second of real time and stamped with simulated time, so pausing the simulation (or slowing it down) does not distort the horizontal axis.
Bus sniffer
The bus sniffer is a table of every transaction seen on the digital buses:
| Column | Meaning |
|---|---|
| Time | Simulated seconds. |
| Bus | i2c, spi, uart, 1-wire, dht or ws2812. |
| Address | The device address, chip select, or direction. |
| Dir | Read or write. |
| Bytes | The payload, in hex (truncated after 24 bytes). |
| Reply / note | What came back, or why the transaction failed. |
A failed transaction is highlighted. The filter menu narrows to one bus, Pause freezes the view while the simulation keeps running, and Clear empties it. The instrument keeps the last 2,000 transactions and shows up to 400 at a time.
Serial monitor
The serial monitor is a terminal for the UART on GPIO14 (TXD) and GPIO15 (RXD). It shows what the Pi sends and what arrives at its receive pin, as text or as hex. The Adapter baud selector sets the speed of the virtual USB–serial adapter at the other end — 1200 to 115200, default 115200. If the adapter's baud does not match the program's, both directions come out garbled, exactly as they would on a bench.
Typing in the input box and pressing Enter sends those bytes into RXD, like an adapter feeding your program. The input is disabled while the simulation is stopped.
Power meter
The power meter shows the current drawn from each budgeted supply rail, with the rail voltage, the running current, the peak seen so far, and the budget. A bar fills towards the budget and turns to "over" when the rail is exceeded. The estimate includes each part's datasheet supply current, along with LEDs, resistors and anything else on the rail.
Recorder
The recorder captures chosen channels (the same picker as the plotter, up to sixteen) at 1, 5, 10 or 20 samples per second:
- ● Record starts a take while the simulation runs; ■ Stop ends it and reports the sample count.
- Download CSV writes the take to a file — the first column is simulated seconds — which works with no server.
- With a backend, stopping saves the take as a recording on the server. The table below lists the saved recordings with their ids and channels; those ids and channel names are what you type into a Recording datafeed to replay the take in another run. See data feeds.
A recording's name is the project name plus the local date and time; its length and channel list are shown in the table.
Files
The Files tab shows the files your program saved with Picamera2 and friends. Images get a preview; everything can be downloaded. The files live for the browser session only, and Clear removes the list.