ESP8266 Community Forum

- Sun Nov 01, 2015 2:19 pm #32762 There is no I2C hardware on the ESP, the implementation is done purely in software by bit-banging the protocol. The errors likely occur, when an interrupt fires during data transmission.
With this in mind, I personally would prefer using the hardware ESP's SPI.

- Sun Nov 01, 2015 2:48 pm #32770 I've made some progress already...

Using example: Basic_ScannerI2C from Sming, I flashed the ESP8266. I put the slave code on an Arduino Uno from here: https://www.arduino.cc/en/Tutorial/MasterWriter

Grounded the two boards, connected pins D1 to A4 and D2 to A5, and specified the pins in the Sming code:
Wire.pins(5,4); // SCL, SDA (D2 and D1).

I assume sming is using software driven bit banded I2C though, can anyone confirm? My testing will continue.

- Sun Nov 01, 2015 2:50 pm #32771

There is no I2C hardware on the ESP, the implementation is done purely in software by bit-banging the protocol. The errors likely occur, when an interrupt fires during data transmission.
With this in mind, I personally would prefer using the hardware ESP's SPI.

Thanks! I was starting to wonder that... my first clue was assignable I2C pins.

Can anyone chime on using the second UART as an option and its viability vs SPI?