Searching for a powerful gong or acoustic notifier? The "Card Sound" consists of audio amplifier TDA7266 having 2x 7 W output, the AD converter CS4344, one STM32F401 and a slot for micro sd card. Objective is to play different sounds stored on an SD card. Current schematic has one TWI port for control. Amend other interfaces like RS-485, UART, SPI etc. is also possible.

Card Sound is playing now. Some unspectacular pictures have been added, but the sound is awesome :-) Software loads several wave files from FAT file system and feeds the CS4344 via DMA. Thanks to cheap SD card memory there is effectively no limit for number and size of wave files.