Corrupting eeprom?

Chris Low wrote 09/02/2019 at 23:02 • 0 points

I am working on a project with the ttgo T-watch which has an Acsip s76g sip which has a lora chip and gps with a uc in a sip. On the t-watch the only coms is via uart. The T-watch also has an Axp202 i2c power control chip. It allows to select the voltage output available. In the example code from ttgo they had set the output of the LDO3 to the s76g to 1800mv. I haven't been able to get a proper datasheet for the s76g. I contacted the manufacturer to get one, but once they realized I wasn't a large company they stopped responding. From everything I have read it is a 3.3v chip. 

I wrote a small program to change some of the parameters of the Lora chip. The commands are sent via serial1 on the esp32 and the s76g acknowledges the change then writes them to eeprom. The program worked fine for a while. I probably had it change the parameters 10 times and then it started having issues. It stopped responding to serial commands. I was able to power cycle and get it to work a few times, but now it won't work at all. I get no response to serial commands. I changed the output to 3.3v and still nothing. Everything else works fine. I just get no response to serial commands. I used a different t-watch with the output set at 3.3v running the same program and it is working fine. 

My question is it possible to corrupted the eeprom by trying to get it to write at a voltage that must be right around its cutout voltage? Does that make sense of could it be something else? Any thoughts on how to fix it?