I am considering an Arduino or PI based project and because I don’t have the competence to properly develop the code (without taking a long time) I am examining the possibility of paying someone to write the code for me. As such the following is the briefest outline of my ideas.
I would appreciate some feedback particularly with regard to the feasibility and complexity of my goals (i.e. can it be done and will it be simple).
I want to be able to use a touch screen (5” or 7”) to independently switch 4-5 audio inputs to any or all of 4 audio outputs. For example, selecting input A on the home screen would then bring up the output screen where any or all of the outputs can be selected, then by pressing a select-enter option the system returns to the home screen where input B, C, D or E can be chosen which again moves to the output screen where any active outputs are coloured and the unselected outputs are free. I am thinking there would probably need to be some kind of block/message (e.g. this output is in use, do you want to switch it to a new input) where an attempt is made to connect an input to a currently active output. One consideration I am having difficulty with is that because this will be regularly powered down, how would the Arduino record which DTDP latching relays are (were) set (to Normally Open) before the power was disconnected, i.e. the latching aspect of the relays means they will still be connected until the reset (Normally Closed) function is triggered.
I would also like to be able to include an audio Bluetooth connection as one of the switched inputs but I’m not sure how to accomplish this, perhaps a separate board.
I am thinking of accomplishing the switching through shift register chips (e.g. 74HC595) triggering DTDP bipolar relays. The relays will most likely all be 5 volt dual coil and be powered separately. As best as I can work out a 4 input - 4 output setup using DTDP relays will need 16 relays with each relay requiring 2 switch pins (one to latch and one to release the relay) making a minimum of 32 shift register pins (so 4 shift register chips) .
For reference, I have included a link to the JOS Functions video (produced by jersagfast) which demonstrates a similar type of operation, I think his settings function is a good idea; [url removed, login to view]
So, what do you suggest/thing, is this a practical idea, Arduino vs PI, onboard vs external Bluetooth?