ESP8266 Community Forum

- Sat Feb 28, 2015 4:25 pm #11004 Okay, I was able to get it to work by using a transistor and inverting the DTR signals in esptool.py.

It seems that DTR straight to GPIO.0 has a problem. Neither pullups, pulldowns, nor a series cap worked.

So I have the DTR line pull GPIO.0 to ground through a transistor. The transistor being an inverter I had to flip the three DTR commands in the script. It could also be done without needing to fip the DTR commands, using the right transistor setup.

- Fri Mar 06, 2015 5:13 pm #11487 I got reliable results without changing anything, just by putting a 220 ohm resistor in the DTR-to-GPIO0 line. I think GPIO.0 causes problems by drawing too much current.

- Sun Mar 29, 2015 5:42 am #12913 Can you elaborate what you mean with putting a 220 Ohm resister between GPIO0 and DTR line? Which is the DTR line? And was this your final fix? Can it be done without soldering?

http://blog.squix.ch

- Sun Mar 29, 2015 9:51 am #12933 I'm not using that dev kit. I have an ESP connected to a CP2102 USB-Serial bridge on a proto board with jumper wires.

The usual connection is this: DTR -> GPIO.0
I modified it to this: DTR -> 220 ohm -> GPIO.0

DTR is the signal line from the USB chip.

And I'm using a 470 ohm resistor now, since it proved to be more reliable. I'm not sure what's going on, but I think the capacitance between DTR and GPIO.0 was causing ringing and the resistor minimizes it.

I can't say if it will work for you.