2021-04-13 09:16 AM
2021-04-13 10:30 AM
The board with an STM32F407VET6 is probably a custom board, isn't it?
If so, then you can easily connect both this board and the STLINK/V2 to a PC at the same time.
Regards
/Peter
2021-04-13 12:20 PM
No, the ground is common, the 5V is relative to the same reference.
The authentic ST-LINK/V2 doesn't use the pin 1/2 VTarget for anything other than the buffers/level-shifters
Also there is a supply pin which could power the other board is some circumstances. Pin 19 3.3V out
2021-04-13 01:53 PM
To P.B. : Yes, this board is custom (from China), and comes w/ an LCD 320x240 screen ILI9341 driven; when USB-plugged alone on a Win7 PC, it turns on, does some self tests, and then tries to communicate w/ his host (PC). Having no driver of any kind nor info on what it could need, I still wonder what this exchange should contain... I will surely learn about it somewhere, I guess. Anyway, thank you very much for comforting me about electrically connecting both devices together w/o risking damages, I'll soon begin to explore the Cube ecosystem that I've downloaded & installed. Thanks again for caring.
2021-04-13 02:18 PM
To T.DL. : Ok ! I don(t know about the authenticity of the STLINK/V2 I have, but it 'looks' ok (for what it's worth); once both devices connected, I'll have a look at the voltages present @ JTAG pins 1,2 & 19 on the target board side, as they are accessible. I think I know STM32' GPIO pins are 5V tolerant, but I didn't know STLINK/V2' JTAG pin 19 could provide the 3.3V supply to the target board, thank you for instructing :) Thank you very much for your info.