ESP8266 Community Forum

- Tue Sep 01, 2015 3:39 pm #27579 I'm using an ESP8266 connected to my computer using a CP2102 and I've been having trouble connecting to and communicating with my ESP12 module.

Flash configuration:
TXD --> RXD
RXD --> TXD
GPIO 0 --> GND
GPIO 2 --> 3.3V
GPIO 15 --> GND
VCC --> 3.3 V
CH_PD --> 3.3 V
GND --> GND

AT configuration:
TXD --> RXD
RXD --> TXD
GPIO 0 --> 3.3 V
GPIO 2 --> 3.3 V
GPIO 15 --> GND
VCC --> 3.3 V
CH_PD --> 3.3 V
GND --> GND

I flash a variation of nodeMCU onto the module. This seems to go fine, thus I believe my flash configuration is fine. When I try and talk to the module with GNU screen or picocom I get nothing or bash hangs or, with picocom, 'FATAL: read from term failed: Device not configured' is thrown and picocom closes.

Any suggestions? Should I be using pull up/down resistors?

swoop swoop

- Tue Sep 01, 2015 4:31 pm #27581

Any suggestions? Should I be using pull up/down resistors?

Yes - needed on GPIO 0 & 2 - 1k to 10k work. Ok to pull GPIO 0 to ground to flash.
This might not cure the problem but its unlikly to work with direct connections.

- Fri Sep 04, 2015 10:32 am #27814

When I try and talk to the module with GNU screen

Make sure when you use AT commands, you have used a AT firmware. I think your connection is good. But I dont think using the GPIO2 connected to VCC is needed.

- Fri Sep 04, 2015 11:27 am #27820

But I dont think using the GPIO2 connected to VCC is needed.

According to https://github.com/esp8266/esp8266-wiki ... ot-Process, you need to have GPIO2 to HIGH.
Of course leaving pins floating can work, but it is certainly not a good practice, it is better having them pulled-up.