Need to control a serial device, such as a micro-controller, with your cell phone? Look no further than the Audio Serial Module. Using free software and open schematics, this module lets you interface your phone or your speaker-equipped surveillance camera with output devices – you can even control a robot with it!
Simple, reliable tiny and inexpensive, the output-only version of this module has only a single active component. You can make your own using the instructions from our Hackaday feature article. Download the free Anroid app here.
We’ve improved upon the design shown below as well, and now offer for sale a version of this device capable of bidirectional serial connection with the Android platform. The updated module still only requires access to the headphone/microphone port and needs no other permissions for the software to run perfectly. If you’d like one, just click here!