Hey everyone - I was hoping to get some additional help on trying to flash this STM102C8 (datasheet attached) micro that controls an APC UPS BR1500G I am trying to repair. I've ran into some trouble connecting to the micro via STMCubeProgrammer.
I am using a FTDI UART to USB cable (datasheet attached) and the STMCubeProgrammer software. I installed the drivers for the FTDI cable as well from their website. I also got a LQFP48 adapter board in case I had to remove the chip from circuit to flash it.
I read the ST application note 2606 to get info on the bootloader function for this chip. Here's how I set it up:
-Connected the VCC 3.3V (red) wire from the FTDI cable to VDD on micro
-Connected ground (black) wire from FTDI cable to VSS on micro
-tied BOOT0 (pin 44) on micro high (3.3V)
-tied BOOT1 (pin 20) on micro low (gnd)
-Connected the TXD (orange) wire from FTDI cable to PA9/USART1_TX (pin 30) on micro
-Connected the RXD (yellow) wire from FTDI calbe to PA10/USART1_RX (pin 31) on micro
-I selected 'UART' in STMCube software and checked to ensure serial configs matched (see photo attached).
Of course, once I was finished connecting everything, I tried to connect and an error message popped up saying 'Error activating device - check bootloader and serial configs and reset'. I double checked everything and powered cycled my setup and tried again - same result. I tried tying the NRST pin low to see if that would reset it, but that still gave me the same error. I tried connecting to the micro both in-circuit and out of circuit.
It should be noted that the reason I am trying to flash this chip in the first place is because I suspect it has some faulty GPIO pins. Pin 27 (PB14) is shorted to VDD. And PB13 (pin 26) is not working at all. These pins are responsible for the AVR function of the UPS. But otherwise the unit works fine. So I assumed I would still be able to interface with it to flash it.
I was hoping you guys could take a look at my set-up to make sure I'm not missing anything (I've attached photos as well). Any help would be greatly appreciated! Also, if the micro is read-protected by the manufacturer, would this explain the error message I am getting?
Thanks!