A little debug help please?

[Wingspinner]

Ok, one of my ESC32s stopped working.After some troubleshooting I've found that the ESC32 works fine when in UART as input but not PWM. Without schematics I'll have to do more work to find the problem but perhaps Jussi or Paul or Bill can answer a couple of questions for me. First, is there some sort of protection on the PWM input line to protect the processor pin or does it go directly to the processor? Second, what pin is it? From the sources it says GPIO_PIN_8 on GPIOA. That says to me pin 29 on the processor. Is that correct? There isn't a PWM signal coming in on that pin.

Some quick confirmation on the physical pin number and the circuitry between the PWM input and the pin would be very helpful.

Thank you!

[Kisssys]

Their is a direct connection to Pin 29 for PWM input.

Have you tried to reflash it?

[Wingspinner]

[Kisssys]

Yes, it does sound related and that pin is definitely shorted with that low a resistance. You could take a pin and lift it up to prove the point I guess. The hard part is figuring out what went wrong.

It could have been as simple as unplugging the device with power applied which I'm guilty of, or static.

I'd rework the ESC as you have little to lose, and just use a different pin out of the FC board. The chips have bootloaders built in so you still don't need a programmer.

I rework a lot of stuff but if I didn't have a Stereo Microscope I'd never get the job done. I've taken the 32f4xx off with just hot air and no preheat with the right attachment.

It has also has been changed using just Chip Quik http://www.digikey.com/product-detail/e ... ND/1164266 which works pretty well.

[Wingspinner]

I'm pretty sure what took out the m13 pin on the processor. My power distribution board also conveniently routes the control signals to the ESC as well as power the ESC plugs into it and so does the FC. Makes for tidy wiring. What appears happened is the connector for the FC may have been plugged in one pin offset such that power and ground from the distribution board may have been connected to m13 and power on the FC. The connection is between the.airframe main frame members and hard to see. Not sure but that may have been it. Not sure why that
Oils affect the ESC32 though.

Anyway, processors and hot air nozzles on order from divinely. I don't have a stero microscope but I do have a very high magnification headset which will be sufficient n

Btw I was also thinking I could just chang the Pwm input on the ESC32 in both hw and SE. That ESC would.always need that special version though.

Thanks for your help. I'll let you know how it goes.

Regards

[bn999]

I rarely need to resort to hot air anymore when replacing the MCU. I'd highly recommend trying Chip Quick first, especially if you have little experience with hot air.

The only requirement for the PWM IN pin is that it is a timer pin that can handle input capture. Not sure if there are any more of those available.

[Wingspinner]

Hi Bill,
I've never used the Chip Quick stuff. I'll give it a look. I could just use another input. Heck, it's got plenty but it's my perfectionism showing....

Regards,
Ron

[Wingspinner]

Update, well, a little more troubleshooting.

I've verified that the ESC32 STM32F103 pin 29 is damaged and will need a new processor - not difficult. More importantly, I found a tiny solder particle shorting the AQ6 processor pin that connects to M13. Cleaned that out and wa-la, it works ok now - no need to repair the AQ6 board!

[joebar.rc]

Perfect, good job.
I also swapped an ESC32 mcu, only the 3rd swap I ever did. With some chipquik it's easy to remove and clean.

[Wingspinner]