Hello,
I have done similar projects already. Please see my portfolio for details.
Regarding the audio send/receive function, is this for stereo music (for example) or just plain speech? If speed what quality, phone or better? This is to estimate bandwidth requirements and needed codecs.
Regarding the legacy wiring system, I will need the wiring specs. Are these common on/off (high/low) signals, or analog (e.g., voice, voltage readings, etc.)?
If you have a specific protocol for the switch control via Internet, please let me know. Do you have or will you create some application for the Internet side? Or will this be a built-in mini-web server on the device itself presenting the three buttons/switches for the browser connected user? (BTW, I assume one connection at a time will be possible, correct?)
I will deliver full production files upon completion.
My bid also includes the cost of a production quality final prototype.
In case the wiring system is of some complexity, how am I to test the module within your larger system? Can it be somehow emulated and tested standalone?
If interested in working together, please contact me. Thank you.