Bricked ESP? GPIO 0 showing 1.5V
Posted: Sat Oct 10, 2015 2:03 am
My device is a ESP-12E board purchased from Alibaba.
Item: I was using this board without issue for a couple of weeks. It has been programmed, reprogrammed multiple times, both via Serial and via OTA.
Item: I have another ESP-12E board from the same order, which is still working fine.
I was programming it via Serial a few days ago, and there seemed to be an error during upload.
Okay, no issue, reset and try again. But now, the upload process starts - but is stuck at 0%. It never moves.
I pulled GPIO 0 HIGH, and reset the device, but it doesn't resume any of its old programming. On each reset, it repeats this string of gibberish (115200 baud):
rl��r��#�n����p�<����8��ǒ��p�nn��;�nĒ���b�$ rr
which is perfectly normal for programming mode. But it's entering programming mode even while GPIO0 is HIGH!
So I measured the pin voltage and it seems that it is permanently stuck at 1.5V, even with the pullup resistor. I even connected it directly to the 3v3 supply and the pin remained at 1.5V. I'm guessing the chip is likely dead, but I would like verification of that fact, and perhaps any guesses as to why / how it happened.
Item: I was using this board without issue for a couple of weeks. It has been programmed, reprogrammed multiple times, both via Serial and via OTA.
Item: I have another ESP-12E board from the same order, which is still working fine.
I was programming it via Serial a few days ago, and there seemed to be an error during upload.
Okay, no issue, reset and try again. But now, the upload process starts - but is stuck at 0%. It never moves.
I pulled GPIO 0 HIGH, and reset the device, but it doesn't resume any of its old programming. On each reset, it repeats this string of gibberish (115200 baud):
rl��r��#�n����p�<����8��ǒ��p�nn��;�nĒ���b�$ rr
which is perfectly normal for programming mode. But it's entering programming mode even while GPIO0 is HIGH!
So I measured the pin voltage and it seems that it is permanently stuck at 1.5V, even with the pullup resistor. I even connected it directly to the 3v3 supply and the pin remained at 1.5V. I'm guessing the chip is likely dead, but I would like verification of that fact, and perhaps any guesses as to why / how it happened.