We’ve looked at the WROOM-DA module before. It’s an ESP32 with two antennas, and [Andreas Spiess] says it is the ugliest ESP32 he’s ever seen. But beauty is only skin deep, after … ...

In the ESP32 module the built-in DAC and ADC are used for audio in and output, which provide just about enough resolution for voice communication. ... The DIY Walkie-Talkie circuit diagram.