Receiving data from Lopy

Hello everyone,

First let me introduce my project: I'm using 2 Lopy (by Pycom), one Lopy reads the data from 2 sensors (BME280 - temperature, humidity and pressure, BH1750 - luminosity) and sends this values via LoRa to the other Lopy.

I have an Arduino UNO with a LCD shield attached to it and I would like to use it show the values sent from the Lopy 1(the one with the sensors) to the other Lopy.

1) Is it possible to use a wire to connect the Lopy to the Arduino? 2) Do I need some kind of bi-directional logic level converter?

Im looking for the simplest solution. I thought of using a wire to connect the Lopy and Arduino but I'm afraid of damaging the Lopy since the Arduino uses 5V and the Lopy uses 3.3V.

Any kind of help is appreciated.

Thanks in advance.

1) Is it possible to use a wire to connect the Lopy to the Arduino?

Yes. But you need three wires.

2) Do I need some kind of bi-directional logic level converter?

Yes, you need a level converter, it doesn't have to be a bi-directional as the UART interface uses defined directions of signals.

If it’s serial, indeed one way. You normally need only a voltage divider on the Arduino TX line, as the 3.3V of the slave TX is enough for the RX of Arduino to recognise it as a high.

Why not use one of the 3.3V Arduino variants? Then, no level shifters are needed.