SparkFun Forums

[jptalledo]

Hi guys

I've just bought a smirf base/remote pair transceiver but I want to know what is the interface voltage for the tx and rx pins in the remote unit. because the PIC16f688 has a 3.3v vdc but in the terminal I measure 0 and 5v.. If I have a 3.3v microcontroller can I interface directly to the pins?? what happened if I have a 5v microcontroller.

Thanks

[MJ]

My reading of the nrf2401 datasheet (which i presume is what's on the smirf) says that the communication lines can go between 1.9 and 3.6 volts.

So, provided you're powering the PIC at ~3 volts you won't get higher than that at the pins. However, if you're powering the two components separately (the PIC with ~5v and the smirf with ~3v) you can't directly connect them or you'll exceed the voltage limits of the transceiver.