The sound module with 20 x 17.5 mm is only marginally larger than a Micro SD card. It has a built-in 1.5 W audio power amplifier and 8 LED light outputs. These LED outputs can be used as equal to the outputs on the cardecoder itself. The connection to the Cardecoder takes place via two lines (CLK and Data, here at the example of the Cardecoder V3)):

The "prog" line for the firmware update from the Cardecoder is used as the "data" line. An update of the sound module in built-in state is also possible via this connection. To connect the LED to the vehicle lighting, the same rules apply as on the Cardecoder itself. The 8 LED outputs and the sound files for the sound playback are configured with the corresponding CV in the Cardecoder (see manual Cardecoder).

The sound files on the SD card must be stored in the root directory as uncompressed 16 bit mono wav files (see manual Sound Extension). As SD cards, cards up to 32 GB can be formatted with a FAT12, FAT16 or FAT32 partition supporting the SPI PIO mode. The PIO mode allows a very simple control of SD cards, which can handle even small low-performance micro-controllers. Micro SD Cards do not need to support this mode anymore, but most cards of popular brands usually do that. Only with particularly favorable No-name cards this can not be the case once again. You have to test them yourself and if necessary use another card.

The OCS Sound Module Handbook can be found in the Download Area . For questions about this assembly, visit our Support Forum and the OpenDCC WIKI.