I recently bought a few of these little guys:
https://www.aliexpress.com/item/32845674676.html
And I would like to put micropython on them.
The chip is the classic NRF52832. They have a CORTEX-M4, 512K FLASH and 64K RAM. It should be more or less ok for micropython and some basic code.
I soldered some pins to the board and powered it. I then did a bluetooth scan and could detect a "Nordic_HRM" device -> the board is alive.
I looked at the nrf port page here: https://github.com/micropython/micropyt ... /ports/nrf, and the board I want to flash doesn't seem supported. But it's based on the NRF52832 module so I have some hope. I successfully built the default firmware (the one for the pca10040 board).
I then went on to flashing the board.
I have a STLINK-V2 connector and I connected it to the SWDIO and SWCLK pins of the board (and to VCC and GND). I installed openocd from the latest commit on github (so it has support for the nrf52 chips).
If I run openocd, everything seems normal:
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❯ openocd -f nrf52.cfg
Open On-Chip Debugger 0.10.0+dev-01383-gd46f28c2e-dirty (2020-08-21-18:25)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
WARNING: interface/stlink-v2.cfg is deprecated, please switch to interface/stlink.cfg
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
nRF52 device has a CTRL-AP dedicated to recover the device from AP lock.
A high level adapter (like a ST-Link) you are currently using cannot access
the CTRL-AP so 'nrf52_recover' command will not work.
Do not enable UICR APPROTECT.
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 1000 kHz
Info : STLINK V2J29S7 (API v2) VID:PID 0483:3748
Info : Target voltage: 3.174546
Info : nrf52.cpu: hardware has 6 breakpoints, 4 watchpoints
Info : starting gdb server for nrf52.cpu on 3333
Info : Listening on port 3333 for gdb connections
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❯ telnet localhost 4444
Trying ::1...
Connection failed: Connexion refusée
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Open On-Chip Debugger
> program firmware.hex
target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0x00015908 msp: 0x20010000
** Programming Started **
nRF52832-QFAA(build code: E0) 512kB Flash, 64kB RAM
Adding extra erase range, 0x00023bfc .. 0x00023fff
** Programming Finished **
> program firmware.hex verify
target halted due to debug-request, current mode: Thread
xPSR: 0x01000000 pc: 0x00015908 msp: 0x20010000
** Programming Started **
Adding extra erase range, 0x00023bfc .. 0x00023fff
** Programming Finished **
** Verify Started **
** Verified OK **
I then disconnected the STLINK connector. I connected the tx/rx pins to a FTDI adapater, and powered the board. I tried to access the micropython prompt with:
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screen /dev/ttyUSB0 115200
Could you please point me in the right direction?
Do I need a special config for my board? Do you see anything weird in the things I did?
I'll be happy to write an article of make a PR if I manage to get this working.