kcoul:
- Am I missing anything? I already have a breadboard and some other components I could possibly use for prototyping
It looks like you have the main components you will need and at first glance either list should make a workable device. However, the intended operational distance is going to be a major factor in determining power usage (since the range is directly proportional to the transmission power). Depending on how far you want the transmitter to work away from what you are interfacing with, you may need increased battery capacity or just live with a charging meaning only a few hours use.
kcoul:
2. Will the simple board have enough pins for what I need? I guess I need 6 separate pins to receive from each button, plus 2 more for rx and tx, but it looks like the simple board only has 6 pins total?
I count a total of nine I/O "pin holes" on the Simple's PCB.
kcoul:
3. If you had a pre-programmed LilyPad, then the FTDI wouldn't be needed, right? I'm hoping to find a way to only need to program the initial prototype unit, then take the finished sketch and have it be loaded onto other LilyPad's prior to being sewn into the velcro strap with the other components. The idea would be to be able to offer a pre-made wearable controller that could be purchased by software users as an optional accessory.
If by "pre-programmed" you mean have the sketch uploaded to Lilypad boards before attaching them to anything, yes. You shouldn't need have any physical connection to a computer for this application to work like you want it.
kcoul:
4. What are some good methods, materials, links, to take the final prototype and sew it all into a velcro strap? I can upload a sketch of how the final strap should look
I don’t know of any specifically for Velcro straps, but you could start with the tutorials over at Sparkfun. A few different attachment methods are shown.
kcoul:
5. Would any other components do a better job than the ones I have listed for my project?
6. Would this project conform to the Bluetooth Low Energy 4.0 protocol, or the regular Bluetooth protocol? I really hope that it wouldn't burn through batteries quickly (though I doubt it would)
As previously mentioned, this will depend upon the useful range you want. The BLE has an advertised range of ~50 m, but that’s your best case scenario. I wouldn’t count on the actual range being that high through obstructions or with interference on the same channels being used. Still in most circumstances it could easily be over half that distance.
But if you use BLE, remember you can’t count on your device interfacing with normal BT devices. So that might end-up limiting its usefulness to some of your customers.