The MIKROE-2902 OOK (on-off keying) RX click board from MikroElektronika is a wireless receiver that operates at the frequency of 433 MHz (sub-GHz). This device allows realization of a simple, low-speed wireless ad-hoc communication network between a receiver and compatible transmitter. It features an ASK (amplitude shift keying)/OOK demodulator, analog received signal strength indicator (RSSI) output, and integrated squelch capabilities. OOK RX click uses the MICRF230 IC, a 400 MHz to 450 MHz ASK/OOK receiver with RSSI and squelch, from Microchip. The working principle of this device is based on decoding of information embedded in a radio signal. The ASK/OOK modulation is a way to encode information and assemble it into radio signals that can be transmitted and received wirelessly. The OOK modulation is like the ASK, but of a binary type. The presence of the carrier signal is recognized as the logical 1, while the absence of a carrier signal is recognized as the logical 0. This method is more immune to noise and interferences than the ASK modulation, and it allows for greater communication distance to be achieved.

The MIKROE-2903 OOK TX click board uses the MICRF114 IC, a 285 MHz to 445 MHz low power integrated RF transmitter, from Microchip Technology. The working principle of this device is based on the encoding of information and embedding it in a radio signal. The OOK modulation is a way to encode information and assemble it into radio signals that can be transmitted and received wirelessly. The transmission signal of OOK TX click is generated by the internal synthesizer section of the MICRF114 IC, which operates at a single frequency. The external oscillator with the base frequency of 13.56 MHz is used so that the RF signal frequency is 433.95 MHz, a perfect match for the OOK RX click, which operates on the exact same frequency. The MICRF114 IC has a single RF output pin, which can be easily matched with the onboard single pole PCB trace antenna.

The MIKROE-2903 and MIKROE-2902 transceiver and receiver can be used for remote low-speed communication applications such as the remote keyless access, remote fan or light control, garage or gate doors control, and any other applications involving unidirectional low data rate wireless links.