Author Topic: Moteino R6 16Mhz suddenly died after months of use  (Read 216 times)

digkarag

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Moteino R6 16Mhz suddenly died after months of use
« on: January 08, 2021, 07:09:28 AM »
Hello,

One of my Moteino R6 16Mhz has suddenly "died".
Measuring the Vout in the LDO gives me a reading of approx. 1.3-1.5 Volts. Tried to desolder LDO and give 3.3v directly to the Vout pin but still dead. If I connect it to the USB-FTDI adapter and try to flash it, the red led is flashing for a white in a weird way and then stops. Flashing stops on uploading state.
With 5V at the Vin pin the LDO gives an output of approximately 3.2V but moteino is still not responding.

Any ideas?
« Last Edit: January 08, 2021, 02:32:54 PM by Felix »

Felix

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Re: Moteino R6 16Mhz, Suddenly died
« Reply #1 on: January 08, 2021, 09:22:29 AM »
You say LED still blinks, that's not dead.
LDO/MCU probably damaged by applying wrong voltage or wrong polarity.
Moteinos don't suddenly die, I have never witnessed one ;)

digkarag

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Re: Moteino R6 16Mhz, Suddenly died
« Reply #2 on: January 08, 2021, 09:45:42 AM »
But blinks in the wrong way. I don't think that LDO is damaged because after removing it and shorting Vin-Vout it's working exactly in the same way.
Also, I am pretty sure about voltage and polarity as I am using three R6 moteino's in the same setup and the other two are working as expected.
Is there any way I can test if the MCU is damaged? Do you ever face any bootloader corruption after several flashings?

Felix

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Re: Moteino R6 16Mhz, Suddenly died
« Reply #3 on: January 08, 2021, 10:28:31 AM »
I would be very interested to hear more if you had more pragmatic context or details than "moteino is dead and things are weird".
What is "blinks in the wrong way"?

Is this a brand new out of box Moteino?
What I know is shipped Moteinos are tested to cover from mysterious DOA/claims. I am however open to hear any evidence if that was not the case.

But maybe there is something physically wrong with the board that started causing the "in a weird way" behavior, and you can show that - ex a shorted PCB trace or something wrong with the radio module that I missed (although it is also tested with the Moteino to transmit/receive). Really .. there is very little room for mystery once a Moteino is assembled and tested.


digkarag

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Re: Moteino R6 16Mhz, Suddenly died
« Reply #4 on: January 08, 2021, 11:46:44 AM »
Let me clarify. I am not claiming that the moteino arrived broken to me or the board is not well-tested.

I am using this board on a daily development for months, however, I don't think that I shorted it somewhere because my other moteino's are working perfectly.
In that specific board, I resolder 5-6 different antennas and flash it hundreds of times, so I just want to repair it if it's possible.
I am asking if it's possible to find a way to troubleshoot the MCU or check if the bootloader is corrupted.

When I talk about weird LED behavior I mean a continuous blinking of 5-6 and weird because the delay between blinkings is not the same and the "weird" voltage drop on the LDO's Vout. Can I understand something from those facts?

Felix

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Re: Moteino R6 16Mhz, Suddenly died
« Reply #5 on: January 08, 2021, 12:07:13 PM »
The blinks are actually triggered by the bootloader. That blinking you describe doesn't sound like its unusual. If the DTR is pulsed repeatedly that can cause that type of blinking before an upload can begin.

I am using this board on a daily development for months, however, I don't think that I shorted it somewhere because my other moteino's are working perfectly.
In that specific board, I resolder 5-6 different antennas and flash it hundreds of times, so I just want to repair it if it's possible.
That's quite revealing, useful to know.

I am asking if it's possible to find a way to troubleshoot the MCU or check if the bootloader is corrupted.
Maybe the bootloader is corrupted although the protection fuses should prevent that, but perhaps not at non compliant voltages, that could perhaps happen, instructions to jump around and randomly delete something in flash.
If thats the case, then LDO voltage needs to be restored to 3.3v, then the MCU can be ISP checked/reflashed with the bootloader, that's what i'd do.
But not sure its even worth the effort, given the history you mentioned I would move on to another Moteino.
Unless you're very remote somewhere and have nothing else to work with.


digkarag

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Re: Moteino R6 16Mhz, Suddenly died
« Reply #6 on: January 08, 2021, 12:59:07 PM »
Maybe troubleshooting requires some effort, but since I use moteino's almost daily I think that's an interesting case.
Also, I would like to try burn again the bootloader so maybe a board that is possible broken is a good choice. No risk  8)

The error I am getting from the arduino IDE is Error: avrdude: stk500_recv(): programmer is not responding

https://support.arduino.cc/hc/en-us/articles/360016478240-Error-avrdude-stk500-recv-programmer-is-not-responding
However, following this guide I check that the program is ok (I am using moteino's FTDI adapter)

So, maybe I should try a new bootloader?
« Last Edit: January 08, 2021, 01:05:04 PM by digkarag »

Felix

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Re: Moteino R6 16Mhz, Suddenly died
« Reply #7 on: January 08, 2021, 02:32:21 PM »
Those errors are not very helpful at all, it just means the programmer cant talk to the bootloader, or something interrupted the transfer.
Do what I said above, you will need an ISP programmer.
But again, IMHO - apart from perhaps learning something, your time is more valuable than a new Moteino (not trying to make a sale!).

digkarag

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Re: Moteino R6 16Mhz suddenly died after months of use
« Reply #8 on: January 12, 2021, 10:47:25 AM »
Currently, it's just for learning. Can I burn the bootloader using another moteino as ISP?

Felix

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Re: Moteino R6 16Mhz suddenly died after months of use
« Reply #9 on: January 12, 2021, 02:07:07 PM »
Sure. But don't ask me how, I tried that once, never again. A few $ for ISP programmer is the way to go. Or better, get Atmel ICE as a more proper tool for flashing AVR and SAMD chips.

digkarag

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Re: Moteino R6 16Mhz suddenly died after months of use
« Reply #10 on: January 13, 2021, 04:45:57 AM »
I won't. You already provide me a lot of information and help! Thanks a lot  8)