Making a SUMP protocol logic analyzer with Raspberry Pi Pico

The Raspberry Pi folks developed Picoprobe, where one Raspberry Pi Pico can be used to reprogram and debug another, using the picoprobe firmware, which transforms a Pico into a USB → SWD and UART bridge. This makes it easy to use a Raspberry Pi Pico on non-Raspberry Pi platforms such as Windows, Mac, and Linux computers where you don’t have GPIOs to connect directly to UART or SWD, but you do have a USB port.

Jaroslav Kysela has forked the code allowing Picoprobe use with a logic analyzer implementation based on the SUMP protocol.

Supported features:

• up to 16 probes (gpio 6-21 by default)
• 200kB RAM for samples
• RLE encoding
• test mode (external pattern)
  • probe 0 and 1 – 10Mhz PWM
  • probe 1 and 2 – 1Mhz PWM
  • probe 3 and 4 – 1kHz PWM
  • probe 8 and 9 – 1kHz PWM (swapped levels)
• test pin (gpio 22) – 5Mhz 50%/50% PWM for probe tests (activated only when sampling)

Overclocking the Pico can give up to a 50 MHz sampling rate.

See more on GitHub.