With no Connection the measured level at the Bluetooth module Tx and Rx pins is 5V, so I assume that means that EZ-B is OK with 5V pulses. However, I am interested in replacing the Bluetooth module with an RF module that outputs 3.3V on its Tx pin. EZ-B will probably be OK with that, but I'm not sure. The Rx input of the RF module is OK with 3-5V.
You could measure the TX signal. If its logic high is 5V, the RX will most likely be 5V tolerant.
With no Connection the measured level at the Bluetooth module Tx and Rx pins is 5V, so I assume that means that EZ-B is OK with 5V pulses. However, I am interested in replacing the Bluetooth module with an RF module that outputs 3.3V on its Tx pin. EZ-B will probably be OK with that, but I'm not sure. The Rx input of the RF module is OK with 3-5V.
It'll take up to 5v. Any voltage greater than 0 is considered ON. So even 1 volt is enough :)
Thanks DJ, that's good info. Thanks to both of you for the quick response.