Hello friends! Today we will connect two nRF24L01 radio modules to two Arduino boards and send a small command from one board to the other. We will start with the radio interface and wiring, install the RF24 library, and then use one complete sketch with a selectable transmitter or receiver role. The useful part of this project is not simply making a number appear in Serial Monitor. We also want to understand which settings must match, what an acknowledgment proves and how to distinguish an SPI connection problem from a wireless communication problem. Those distinctions make the same hardware much easier to use in a sensor node or remote-control experiment. The examples below target two Uno R3 boards and ordinary nRF24L01+ modules. The original wiring illustrations, demonstration video and ...