Hey folks, my GIGA R1 is giving me some problems. I'm unable to enter bootloader mode (flashing green light) even though i double press the RST button. I have tried all sorts of things, tried to use the STM programmer used the command prompt but none of them seems to work since they connect to the dfu port which is available only when you enter the bootloader mode. Don't know the exact cause however, prior to the issue i connected a 9v battery to the VRTC and GND pin to use the inbuilt Realtime clock. did it damage the board somehow?
Hi @temperate.
I think it must have. VRTC is connected to the VBAT pin of the GIGA R1 WiFi board's STM32H747XI microcontroller. If you consult table 19 under section 6.2 ("Absolute maximum ratings") in the STM32H747XI datasheet, you will see that the absolute maximum voltage rating for the VBAT pin is 4 V. So I think that subjecting the pin to 9 V is likely to have done significant permanent physical damage to the microcontroller.
Unless you have the right tools on hand and the skills to use those tools, repair of the board will not be feasible. I suggest you attach a note to the damaged board describing what is wrong with it and put it in your electronics salvage bin. Then purchase a replacement board.