I2c wiring on Wifi Kit 32 v3.1

#1

I am attempting to wire a Adafruit INA260 to a Heltec Wifi Kit 32 v3.1. I’m unable to do this as it isn’t clear which pins are wired to the secondary i2c. I know that I can wire two i2c devices to a Lora 32 v3.2 without issue, but the pinouts are different between the two boards. I’ve attempted wiring to pins 17 - SCL, and 18 - SDA on header J3, based on various information, no success. I’ve also attempted using pins 5 & 6 on J3, also no success.

Could someone provide an updated pinout diagram, as this is frustrating, as between this and the pins_arduino.h not seeming to line up, I’m ready to either use a Lora board (which isn’t needed for this application), or go over to a Pi (which is overkill for this).

Please help!

#2

This issue comes up regularly enough: http://community.heltec.cn/search?q=i2c%20order%3Alatest

The secret being that you have to define a second instance of Wire as the first one is being used for the display.

#3

Thanks for the response nmcc, and I’ll give that a try shortly, but still the question remains: mapping of the physical pinout to the pin assignment within the pins_arduino.h/actual function per pin.

I’ve done i2c development on Pis previously and this is confusing at best, frustrating at most, and I’m really not trying to damage components while developing. Call me cautious, but right now my development budget is my own and not a company’s, so less mistakes the better.

#4

You can refer to the schematics. But also consider that the bigger MCU’s can route many different function blocks like I2C, SPI or UART to any pin - with ESP32 you create a second instance of Wire and begin() with the pins you want to use.