Upload issue with ESP8266 - DTR output 1.7V
Posted: Fri Mar 30, 2018 2:06 am
I have been programming an ESP8266 on a custom board. The DTR pin is pulled up to 3.3 via 10K resistor and also a tactile switch SW4 is connected to it (Circuit attached). The switch connects it to GND when pressed. I was able to program it couple of times but after I tried a minor soldering attempt on DTR pin, I am getting the following behavior.
1. When i reset, The existing program works, The Voltage level on DTR is pulled up correctly to 3.3V andd at button press, it drops down to GND and ESP can detect the button press
2. When i start to program it, ESP Resets but i Get
3. using logic analyzer, i captured the following, After RST goes low, DTR goes low but when released DTR stays at 1.7v instead of 3.3.
Do let me know is this a normal behavior and how to fix it.
1. When i reset, The existing program works, The Voltage level on DTR is pulled up correctly to 3.3V andd at button press, it drops down to GND and ESP can detect the button press
2. When i start to program it, ESP Resets but i Get
warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed
error: espcomm_upload_mem failed.
3. using logic analyzer, i captured the following, After RST goes low, DTR goes low but when released DTR stays at 1.7v instead of 3.3.
Do let me know is this a normal behavior and how to fix it.