Picoprobe with the 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)

Limits:

50Mhz sampling rate when compiled with the TURBO_200MHZ define (otherwise 31.25Mhz)
basic triggers are implemented (functional up to 10Mhz - TODO: PIO support)

This protocol is supported in sigrok as openbench-logic-sniffer:

  pulseview --driver=ols:conn=/dev/ttyACM1
    
  sigrok-cli --driver=ols:conn=/dev/ttyACM1 --config samplerate=50Mhz \
             --config pattern=External --samples 256 --channels 0-1

Compile:

  mkdir build
  cd build
  TURBO_200MHZ=1 PICO_SDK_PATH=/opt/pico-sdk cmake ..

Compile RAM code (debug):

  mkdir build
  cd build
  TURBO_200MHZ=1 PICO_SDK_PATH=/opt/pico-sdk cmake -DPICO_NO_FLASH=1 -DCMAKE_BUILD_TYPE=Debug ..

Misc:

picoprobe reset pin is on gpio 28 (instead 6) now

Link to protocol | Link to libsigrok

perexg/picoprobe-sump

Picoprobe with the logic analyzer implementation based on the SUMP protocol