Pico and ESP8266

The No 'ready' after AT+RST error also appears when CH_PD has not been set to 3.3. It happened to me too because I don't use the shim.

So to summarize:

• The serial connection needs to be cross wired. ESP8266 URXD => Pico TX and ESP8266 UTXD => Pico RX
  
• ESP8266 CH_PD needs to be connected to the Pico 3.3.
  
  

What I saw until now is that the wifi module seems a bit unstable. I get random errors when connecting. For example:

• SD card must be setup with E.connectSDCard first on module init.
  
• No change when trying to connect to a wifi network.
  
• CIPSTART failed after connection to wifi has been established
  
  

Usually a reboot solved the issues and it works fine for some time. I will try to keep an eye on the issues. I think it may be related to the AT commands. Maybe the prior command is still in the command buffer of the ESP8266 after I restart the Pico.