Posted by Arielo on 2017-09-25 17:00

EDIT: Scratch all below... it was a faulty wire between the Discovery board and my custom PCB. Programmer works ok.

Hello, I’m new to STM32, and I’m learning how to use these MCU with a discovery board (STM32F0Discovery).

I’m usign AC6 and CubeMX on linux (Ubuntu 14.04).

I’ve been able to program the device, and try different stuff on it (timers, I/O, nokia 5110 lcd, ADC, etc). I haven’t had any issue programming the device using the on board ST-Link V2.

Now, I’ve built a PCB with an STM32 MCU (STM32F070F6Px), and I wanted to use the Discovery board ST-Link to program this PCB.

I use the SWD header on the Discovery board, and removed the jumpers on the other header, to use it as an external programmer. I’ve connected the SWD header to my custom PCB, using the lines on the image:

I cannot program the device. I get the following error:

Open On-Chip Debugger 0.10.0-dev-00004-gcef2a8c-dirty (2017-08-31-14:01)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
none separate
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
adapter speed: 950 kHz
adapter_nsrst_delay: 100
Info : clock speed 950 kHz
Info : STLINK v2 JTAG v28 API v2 SWIM v0 VID 0x0483 PID 0x3748
Info : vid/pid are not identical: 0x0483/0x374B 0x0483/0x3748
Info : using stlink api v2
Info : Target voltage: 2.911124
Error: init mode failed (unable to connect to the target)
in procedure ‘program’
in procedure ‘init’ called at file “embedded:startup.tcl”, line 473
in procedure ‘ocd_bouncer’

• OpenOCD init failed **

shutdown command invoked

I’ve tested the Rst line with an Oscilloscope, and when I try to flash the chip, it goes low, and stays low, it doesn’t go back up.

Please, I need help with this.