“The ESPboy Walkie-Talkie module uses SA868 transceiver allows you to use your ESPboy as an Walkie-Talkie radio. You can buy this module ready-made or make it yourself.
1.1 SA868 module
1.2 LTK5128 amplifier board
1.3 MAX9814 microphone (i used one with manual gain adjustment)
1.4 speaker 4Ohm 3w (i used speaker from the old notebook)
1.5 antenna connector