@slyderule Hi!
C3 has the I2C "PORT A" on the left side beside the USB-C port, pins G1 and G0. You can see it on the supplied sticker!
"Module peripheral interface resources ADC, GPIO, SPI, UART, I2C, I2S, PWM, RMT, DMA, USB serial port, TWAI"(from the Specifications list)
Hope this helps, cheers, Terry

@felmue Hi Felix, me again.
Regarding the PaHub:
I found the Official M5Stack PaHub example to be of little help to write a useful project with 2 sensors with the same I2C address. I made this example very minimalist using a M5Stack Core Basic controller.
PaHub Example with 2 ENVII temperature sensors:
I put it on GitHub https://github.com/teastainGit/Simple-PaHub-example
Would you have time to look it over and "Maybe" submit it to M5Stack? To be added to their example for PaHub?
If not could you tell me how to submit it? I am asking you because you have a great reputation with them!!!
Cheers! Terry

@caiotesio if you are interested...email me the program and I'll try it on my Core2.
Or...slug away! It's sometimes fun and instructional to troubleshoot yourself!
teastain@me.com

@caiotesio
Hi!
They are very different, actually, the most obvious is needing it's own library,
#include <M5Core2.h>.
More here:
https://docs.m5stack.com/en/core/core2
Cheers, Terry

@nicholas-parasporo
Hi! The PaHub can support two devices of the same address. It is an I2C device splitter, which can expand a single Grove i2c interface to six channels, and allows you to mount slave devices with the same I2C address.
More here!
https://docs.m5stack.com/en/unit/pahub
Cheers, Terry

Thomas, so glad to help, I love ESP_NOW !!!
All my maker stuff is now M5Stack!
Cheers, Terry

Hi Thomas. The desk is wooden.
But you can expect typical range and "through walls" of a WiFi router in your house.
WiFi uses quite a bit more current than you might think.
I run mine on 5V iPhone white cube USB power supplies.

Hi, I have a Core Basic HVAC program communicating with two Stamps using ESP_NOW and they are physically close, but the idea was to not run messy cables! The ESP_NOW is peer to peer WiFi, but no login to the internet or even the WiFi router.
One Stamp reads the HVAC vent temperature and reports to the Core, which in turn calculates the damper vane angle and transmits that back to the very same Stamp connected to a 180 servo motor.
The other Stamp just operates one or two small under desk heaters as required, by the Core.
Hope this helps.
Terry

@felmue GOOD JOB!
I downloaded the new library and made a mixed program with one pin Output and another RGB...
Works perfectly. I studied your library...maybe next time I will try!
Much thanks, Terry

@felmue Thanks Felix, I'll try it once The Powers That Be approve !!!
Does it work for you?
Thanks Terry