This Audio Alert box is placed between an audio source and an audio consumer such as an FM transmitter or amplifier. When the alert box wirelessly receives an encoded message, it breaks into the audio stream from the source and plays the mp3 sound clip related to the message received.
See the original Audio Alert description for more: https://www.thingiverse.com/thing:2754869
This new version uses different components and is designed around a finished SMD PCB.
This 2nd version of the Audio Alert project was originally designed to support the 2nd version of the Dust Collector Full board that uses the same transceiver (See https://www.thingiverse.com/thing:2657033). I decided to make the board design somewhat extensible. All of the unused MCU pins have been brought out to the edge of the board for future use along with a dedicated I2C connector to allow for a future display and/or keyboard, etc..
The sound quality of this board is better than the original board. The original board uses a generic analog switch rather than an actual audio switch as used in this new design.
This design also gives you three MP3 sources: onboard NOR Flash, USB memory stick, or SD card. This is essentially a fully implemented stereo version of the YX5200-24SS chip on the mono DFPlayer module.
The NOR Flash requires the image of a FAT file system. All MP3 files should be in the root directory. The NOR Flash can be loaded prior to building the board or after via the NOR Flash connector on the board. For either case I wrote a MacOS application to create a FAT file system with selected MP3 files exported in Intel Hex format, and Arduino sketches to unpack the HEX and store the result on the NOR Flash chip. See: https://github.com/JonMackey/FatFsToHex
I’ve never sold anything on eBay and when I went to setup my first listing I realized that I could not embed a link back to Thingiverse. Because of this I will only be creating eBay listings on demand. If anyone in the US is interested in purchasing this board or any boards that you’ve seen in my other Things, send me a message. The prices are very reasonable.
For anyone outside of the US (or in the US and you’d like to build the board yourself), the Gerber files are shared on PCBWay.com. PCBWay is a low cost high quality PCB manufacturer located in China. They ship worldwide. https://www.pcbway.com/project/shareproject/Audio_Alert_v2_3.html
The assembled eBay PCB comes preloaded with three messages: “Dust collector full”, “Someone is at the front door” and “Someone is at the backdoor.”
Prints: I printed both at, 20% fill, no support.