A ham radio foxbeacon made from the CH9300 mp3 playback board
https://www.aliexpress.com/i/3256806689097430.html?gatewayAdapt=4itemAdapt
the CH9300-FL version has 16mb of onboard memory. or about 15min of audio playback if the 3rd switch is on and the other 2 are off it will just play the files in order on a loop. Example
poweron.mp3 00001.mp3 00002.mp3 00003.mp3 ect..
The DAC pin is the linelevel out for the radios mic input, on a baofeng or other kenwood compatable radios this is the left channel on the 3.5mm stereo plug The ground on the other side of the board is both the ground for the mic jack and the power to the board.