NRF52840_USB_DONGLE

Note

This tentacle currently may NOT run micropython tests as flashing is not implemented

Tentacle spec: See NRF52840_USB_DONGLE in src/testbed_micropython/tentacle_specs.py

The goal of this tentacle is to verify if SWD and the levelshifter works ok.

Test SWD: A NRF52840 is programmed using the PICO_PROBE (with pico-probe-firmware) via level shifter on 1.7V.

There is a simplified version of the test where micropython is used to apply a square wave signal.

Flash DUT using PICO_PROBE

Start picoprobe and DUT

op power --on proberun --on dut

Flash Erase

openocd -f interface/cmsis-dap.cfg -f target/nordic/nrf52.cfg -c "gdb_flash_program enable" -c "init; nrf52_recover; exit;"

Flash Adafruit Bootloader

wget https://github.com/adafruit/Adafruit_nRF52_Bootloader/releases/download/0.9.2/pca10059_bootloader-0.9.2_s140_6.1.1.hex
export IMAGE=pca10059_bootloader-0.9.2_s140_6.1.1.hex
openocd -f interface/cmsis-dap.cfg -f target/nordic/nrf52.cfg -c "gdb_flash_program enable" -c "init; nrf52_recover; program "$IMAGE" verify reset exit"

Test the level shifter using micropython square wave signal

Program PICO_PROBE with pico-probe-firmware

op bootmode-probe

download uf2 from https://github.com/raspberrypi/debugprobe/releases<br> place on drive RPI-RP2

op bootmode-probe
wget https://micropython.org/resources/firmware/RPI_PICO-20250911-v1.26.1.uf2

Apply the square wave signal

op power --on proberun --on dut

# micropython
# CLK GPIO2
# DIO GPI03

from machine import Pin
import time

pinGPIO2 = Pin("GPIO2", Pin.OUT)
pinGPIO3 = Pin("GPIO3", Pin.OUT)
pinGPIO4 = Pin("GPIO4", Pin.OUT)
pinGPIO5 = Pin("GPIO5", Pin.OUT)

counter = 0
while True:
    pinGPIO2.value(counter % 2 == 0)
    pinGPIO3.value(counter % 3 == 0)
    pinGPIO4.value(counter % 4 == 0)
    pinGPIO5.value(counter % 5 == 0)
    time.sleep(0.01)
    counter += 1