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Lab 02: Give the Kit a Checkup

02-probe.py is a doctor's visit for your kit. It checks everything that software can check and prints a report in Thonny's shell. Run it on a new kit, and again any time something stops working.

Welcome to Lab 02

Chrono waving welcome This program does the detective work for you. In about half a minute it tells you whether a problem is the board, the files, the wiring, or your own code. Let's make time tick!

What You Will Learn

  • what the Pico W has inside: its chip, memory, and storage
  • which kit files must be on the board
  • how to read a test report and act on its warnings

Run It

Open 02-probe.py in Thonny and click Run. The report has eleven sections:

Section What it checks
1. Board and firmware Which chip, which MicroPython, how fast the processor runs
2. RAM How much working memory is free
3. Flash How big the storage is, and every file on it
4. Kit files Are the display driver, fonts, config.py, and sound files on the board?
5. Power and sensors USB power, the chip's temperature, the BOOTSEL button
6. WiFi The board's MAC address and the networks it can see
7. Real-time clock Has anything set the time yet?
8. Buttons Are MODE, UP, and DOWN all reading "not pressed"?
9. SPI bus The speed the display connection really runs at
10. Speaker The BCLK/LRC pin rule, the GAIN pin, and three rising beeps
11. Display Starts the screen and draws color bars and "Probe OK"

The report ends with a Summary that lists every warning. Fix those first.

Why can't it check the screen and speaker by itself?

Chrono thinking Notice that the Pico only sends to the display and the amplifier; neither one can answer back. So the last two checks need your senses: if you see "Probe OK" and hear three rising beeps, both work.

Nothing Can Break

The probe only reads. It never writes a file or changes a setting, so it is always safe to run. Set PLAY_BEEPS = False at the top of the file for a silent checkup.

If It Doesn't Work

  • "... is not on the board -- run upload-code.sh". The kit's files aren't on the Pico yet. Close Thonny and run upload-code.sh.
  • A button reads "pressed" when you aren't touching it. That button is turned the wrong way in the breadboard, so its legs are always connected. Turn it a quarter turn.
  • An error in the speaker section. BCLK and LRC are swapped. See the wiring warning on the kit's main page.

Checkup Complete!

Chrono celebrating You can now read a hardware report and turn each warning into a fix. When something goes wrong later, run this lab first.

Next: Lab 03: Test the Buttons