ESP8266 Community Forum

- Thu Aug 03, 2017 3:54 am #68792 Hello,
I have been Trying to use a MCP23017 with ESP8266 for couple of days with Unsuccessful Results.
The Problem is, 30%~ of the Reboots, ESP8266 Recognizes MCP23017 and Rest of the Time it just simply ignores it.

I am using Adafruit MCP23017 Library and MCP23017 Connected to I2C on ESP8266 Default 4, 5 Pins .

Pull-Ups are 4.7KOhm .
Please Tell me a Fix for this!
I Ran the I2C Scanner Code, It gives the Same result, Sometimes Detects the MCP and Sometimes not.

- Thu Aug 03, 2017 4:33 am #68794 Ok So, It was a Hardware bug in my Project.
Make Sure Everybody Connects RST Pin on MCP23017 to VDD .
It Worked Fine after This .