I have a MicroPython pyboard v1.1. It contains the STM32F405RGT6 chip. When I try to debug with ST link V2 debugger it just light up all the LEDS and says "no device found" on the STM32CubeIDE 1.90v.

[cjaya.1]

This is the MicroPython pyboard v1.1 that I try to debug with ST link V2 debugger

https://store.micropython.org/product/PYBv1.1.

it just light up all the LEDS and says "no device found" on the STM32CubeIDE 1.90v. Any idea about this?

[Bob S]

How do you have the STLink connected to the board? Do you have the programmer software configured to connect under reset?

[cjaya.1]

Thank you for the reply. I have connected the STLink to board as SWIO and SWCLK ,NRST to reset of the pyboard and Target Vcc to 3.3v of the pyboard. And the programmer reset behaviour Type set up as "Connect under reset" on the STM32CubeIDE.

[Bob S]

I meant my question towards a more detailed answer: which pins on the STLink to which pins on the python board?

You have access to the BOOT0 pin, try forcing the internal bootloader to run then connect via UART or USB (presuming those are connected to the correct pins for bootloader use, see AN2606).

It has been a while since I've looked at this, but could it be that the CPU has been programmed for RDP level 2, which prevents ANY debugger access? I don't recall how the STLink reports that.

[cjaya.1]

STlink pin 7(SWIO) connected to P5 of pyboard

STlink pin 9(SWCLK) connected to P4 of pyboard

STlink pin 2(Target VCC) connected to 3.3V of pyboard

STlink pin 4(GND) connected to GND of pyboard

STlink pin 15(NRST) connected to Y13 of pyboard

This is the schemetic of pyboard:

https://micropython.org/resource/PYBv11-schematics.pdf

Yes, I was able to use BOOT0 to run internal bootload and then connect via USB. And I am able to flash the .BIN file.

But I wanted to use the debugger to step through each stage.

[Sarra.S]

Hello @cjaya.2kody​,

You need to pay attention to BOOT0 and BOOT1 pins, generally when programming with SWD and STLink, you need to pull BOOT1 and BOOT0 down to ground with pull down resistors.

From the schematics I can see that BOOT1 is internally pulled down. I'd pull down resistors on both with at 10k resistor, 47K would also be fine.

Also, you should try STM32 Cube Programmer first to check if you can talk to your STLink device.

Sarra