Economical Narrowband Radio Modem
February 2025
The new CNM2 from low power radio specialist Radiometrix, is an inexpensive, easy to use, compact low power 25kHz narrow band GFSK radio modem module that supports a 4800 baud rate link with a 3.3V logic UART interface. CNM2 is frequency programmable and available from 420MHz to 470MHz covering 419MHz (China), 433MHz (EU, Australia, Brazil, South Africa), with a TX power of up to 50mW (depending on the band).
Operating in two distinct modes (transparent and command) the module provides support for different application uses. Transparent mode is ideally suited for tasks where there is a relatively high data throughput requiring less timing control, such as when essentially a very simple ‘wire replacement’ is required. Command/packet mode is ideal when there is less data to send, but more control is needed over transmission times and duty cycle, such as in telecontrol applications and for low duty cycle, low average current tasks.
There is also a CNM3 version available on standard 865-867MHz (India), 868-870MHz (EU) or 915-928MHz (North & South American, Australian frequencies). The CNM2/CNM3 Evaluation Kit with RS232 interface and bus activity LEDs can be used for testing and evaluation.