Praat is a remarkably un-photogenic box for playing Silhouette Range Commands over two-way radio. It consists of an ATmega328 (think "Arduino") microcontroller, a DFPlayer Mini* MP3 player (beware of these, there are two models, the one is barely useable and the other doesn't work at all) and a Baofeng 888 radio. The User Interface is a 20x4 LCD screen and four buttons. It's powered from a 12V SLA, using two Mini360 buck regulators, 5V for the control and 3.7V for the Baofeng.
Depending on which button is pressed, the processor plays the commands in a loop four, five or six times, then calls cease fire (the fourth button aborts the string). The Baofeng is keyed from the MP3 "busy" output.
I'm also using the A/D converter to give an indication of the battery level.
This is the prototype and also the full production run. We only need one.
Avoid the 16-pin MH2024 version/