Grove connectors: UART and I2C

[jamstooks]

The UnitV2 appears to use a UART connection with the same HY2.0-4P Grove connector as other peripherals that use I2C.

If I wanted to connect multiple peripherals and a UnitV2 camera to the Core2 (which only has one Grove port), I can't simply use the Grove-T or the PbHub, right?

Would I need a port expansion module, like the COMMU to get the additional I2C ports?

[ajb2k3]

You need a PAHub to increase I2C ports, PBHub is for analog devices only.

[felmue]

Hello @jamstooks

@ajb2k3 is correct, the PbHub is for analog devices only and cannot be used for UART.

Unlike UART, I2C is a bus and can handle multiple units (as long as the units use different I2C addresses). So if you want to connect multiple I2C units to you M5Core2 you can use a Groove-T.
However as soon as some units you wish to connect share the same I2C address you need a different solution. You have two options:

• the units in question allow for the I2C address to be modified
• use a PaHub (like @ajb2k3 suggested)

As for connecting the UnitV2 to your M5Core2 via UART: I would suggest the Battery Bottom 2, which has been designed for M5Core2 and it gives you the UART port needed.

The COMMU module should work as well, but as it has been designed for the M5Stack (Basic, Gray, Go, Fire) there seems to be some incompatibility issues like while the COMMU module is stacked to the M5Core2 the M5Core2 cannot be flashed.
(Note: I don't have the COMMU module, so I cannot confirm that issue.)

Thanks
Felix