DRA808M is a type of compact wireless voice transceiver module based on RFIC RDA1845. It integrates high speed microcontroller, high performance wireless transceiver IC, high power PA, audio process and squelching circuits. It provides standard UART interface which users can easily configure appropriate parameters for different applications. Users can easily construct a walkie-talkie system by connecting microphone, audio PA and speaker.
DRA818U is based on RFIC RDA1846. It has the same pin sequence and dimensions as DRA808M module so users can replace the DRA808M with it directly. Comparing to DRA808M module, DRA818U are added with CDCSS function except CTCSS and AT command-SETFILTER which users can use it to turn on/off Pre-emphasis/De-emphasis funciton, High pass filter and low pass filter.It provides users more flexibility in process audio signal for different applications.
DRA818V is the VHF band version of DRA818U module. It works at 134MHz~174MHz which covers the common HAM radio frequencies such as 144MHz, 145MHZ, 146MHz, 154MHz, 157MHz,160MHz, etc. It has the same function and pin layout as DRA818U module except the frequency so users can easily exchange the two modules according to the requirement and do not need to make second development in hardware.