it’s an Arduino-compatible microcontroller board for interfacing with radio frequency (RF) modules, such as the popular 433/315MHz transmitter/receiver, and the nRF24L01 transceiver. The RFToy has a built-in ATmega328, USB-serial converter (CH340G), 128×64 OLED display, three buttons, and a coin battery holder. Programming is done in Arduino through the on-board mini-USB port. It has three sets of pin headers to directly fit RF modules, and an audio jack to output RF receiver signals to a computer’s sound card. Using RFToy you can build a variety of projects involving RF modules, such as remote control and wireless sensors. [ ]