Chris from PyroElectro was looking for a way to miniaturize his previous VGA test box to make it more suitable for portable use. He came up with this design for a Mini AV Test Box for portable testing of VGA displays and speakers.
His project fits a full fledged AV tester into a mint-tin can with minimal requirements for using it. The design features a PIC 16F84A and 555 timer. Nothing complex, just a quick RGB display pattern to determine whether a display’s 800×600 VGA functionality works, and a variable tone oscillator to check whether a speaker or pair of headphones are operational.
Source code in assembly, schematic and PCB Eagle files are provided.