P1 UART 5V Tolerant?

I am using the P1 module to read and send data from a 5V MCU - In the datasheet of the P1 some PINs are marked as “5V Tolerant” - However currently I’ve planned to use a level converter here but when this isn’t needed I would leave it out. But this would also require that the P1 does provide 5V signals!? Is this the case? Or is it better to have level converter between UART of P1 and MCU?

The info which pins are 5V tolerant can be found here

And whether your “client” can deal with 3.3V HIGH on RX to recognise the bit correctly depends on that device and is beyond us to know.
The respective datasheet should give you some info about the level thresholds. In general I’d think it should be OK.


Thanks for this information. Unfortunately the MCU does not deal with 3,3V HIGH - so there is level-shifting needed. I just thought that if the Photon can deal with 5V UART I somehow thought that it sends out 5V on TX. But it doesn’t, right!?

Nope 5V tolerant does only mean 5V can be tolerated at that pin but it does not mean it’ll ever output 5V.