T-RSC3 bricked (2 units!)

txinto

Hi, I am trying to do my own firmware for T-RSC3. I bought one months ago, I executed the example, ok. Then I just simply wanted to create a new project using ESP-IDF samples, for doing OTA. After flashing it, the unit became bricked. The device never connects to the PC, no serial port. I'm using Linux, but I tested it in Windows. The board is death.
The vendor refund me, and I purchased two more units (I need 485 in my project, and your device fits very well). Then I executed the example code from Lilygo, ok. Then I flashed another example (totally different from the OTA example months ago), which caused the unit to reset. After a while, in the serial line there was garbage. After unplugging the unit, it's bricked the same way.

No physical damage, different projects, and same result. Is the hardware so weak? How could this happen and how can I prevent it to happen? Have you seen it? Are you planning to fix it?

Regards.

Tx

teastain2

@txinto You have a very uncommon module and I think this "community" site, which is mostly supported by users (usually me) will not get any answers!
Please try:
https://github.com/Xinyuan-LilyGO/T-RSC3/issues
and raise an issue.
Their response time is terrible, so you may have to email them @
sales@lilygo.cc

BTW OTA is like uploading sketches via USB, but much more complicated and risky. So you may have a case where the units are deployed far from you but they have WiFi connection...I would try uploading simpler test sketches to be sure that they are functional.
What IDE are you using to program?
It is very hard to Brick a ESP32 but sometimes the sketch you loaded causes CPU crashes like Kernal Panic. The trick is to find it's reset pins and try combinations of resetting until it can upload a simple serial monitor test with a time delay like this one I wrote:

bool ticktock = true;

void setup() {
Serial.begin (115200);
}

void loop() {
ticktock = !ticktock;
  if (ticktock) {
    Serial.println("tick");  
  } else {
    Serial.println("tock");
  }
delay (1000);
}

Regards, Terry

txinto

@teastain2
Thanks Terry for your response. Sorry for not having seen this thread in many time, I just simply put them in a drawer and moved to another devices.

Time today is gold.

Thank you again, for your gold.

Tx.