Hy, I have two vesc 6 here. Ive changed the mcu and Iam able to upload the bootloader via st link without any problems. After that the USB just does not get connected or recognized (nothing in the device manager etc), I ve just tried with the 4.12 bootloader and with it the USB gets recognized but it says USB Device not usable (So at least it recognizes a usb device). Ive changed the resistors to new ones that are in the line from the MCU to the USB. Ive checked all the pins of the MCU. Everything should be fine. Both vesc6 the problem is exactly the same. I dont think its the USB port itself because it gets recognized with the 4.12 bootloader I just cant do something with it. Any ideas? Thanks
The mcu are 100% the correct ones
normal vesc 6, not + or mkIII
double check your soldering on the MCU.
Check that your regulator outputs are alive and well.
Do you have a working vesc to dobule check your connection to the PC is alright?/change PC
…and if not too obvious, your vescs need power from something (preferably a dc supply with current limiting), not just the 5V from the USB
yes 3 PCs, 3 cables, new mcus its the same the whole time. 3.3 and 5v are totaly okay. it has to be something with the vescs. maybe the traces but I measured from the usb to the pins from the mcu and they have contact… I dont get it
ive took the original bootloader for vesc 6. The wired thing is with 4.12 bootloader the usb gets recognized but only with “USB device isnt connected proberbly” in WINDOWS. I am brainstorming atm what else could be wrong. Thanks for your help btw
hmm, odds of you having two bad USB connectors are slim but try to apply some flux on the legs and reheat each pad. Maybe replace those series resistors with a solder bridge(0 Ohm). (leave R1 not mounted tho)
Sometimes DMM shows good connection but in reality its weak with some more current on it.
What else?.. hm…
Try a different bootloader for science?
Isn’t there a tutorial for how to ressurect a bricked vesc with another vesc somewhere? (eliminating the PC part)
Meassuring GND->3.3V and GND->5V when powered down should yield kOhm or higher.
Check MCU again, (should be STM32F40X_LQFP64)
uuuh, what else… Have you done a visual inspection of the entire PCB? Anything that looks suspicious?
So now I dont get anything anymore. Ive took the mcu and placed it on another vesc 6. After uploading the bootloader for vesc6 (the one @Mainflow gave me at the github from vedder) I had exactly the same issue. So ive tested it with the 4.12 bootloader. And usb worked perfect, now I was able to bootload the correct bootloader in the vesc tool and loaded the vesc6 firmware. But why did that work now with another vesc6. And why does the vesc6 bootloader didint do his job… question over questions . ^:3 Now iam going to copy the bootloader on the working one and try to save it so I could upload exactly that hex code to the other vescs
this was 3 years ago, I am not sure anymore what was the problem most likely a bad solder connection or faulty mcu. check for solder connections first. especially the pins for usb and st pins from the mcu. also check the resistors on the usb lines
You can try upload the bootloader via st and then if you lucky, go into vesc tool and do the bootloader upload again via vesc tool and only then upload firmware. This should work
most likely a bad solder connection or faulty mcu. check for solder connections first. especially the pins for usb and st pins from the mcu. also check the resistors on the usb lines