My colleague and I are trying to design a simple, cheap, easy-to-make classroom voting system using IR to communicate with a central teacher computer, that can project the results on a screen in the classroom. Our priorities are:
Simple to make and reproduce - we plan to open-source both hardware and software.
Cheap to make - ideally around £3 per handset
Easy to get up and running - by making it functionally straightforward and providing all the necessary documentation.
We both teach full-time and so are working on this in our spare time.
Initially, we're looking for help with the transmitter, making it as efficient as possible. We're using a Genie microcontroller, which is configured for 4 inputs and 1 output. The output is to the IR LED. At the moment, it's got a range of around 4-5m, but we'd like to increase that to as much as possible.
We want to keep the PCB as simple as possible, sticking to through-hole soldering and a single-sided board.
We're using an education-focussed CAD package called Circuit Wizard, which allows us to code and program the chips.
Do he results need to be recorded to a computer? Another interesting method for this is to put and RGB led and IR receiver on each one. When the student pushes the button it stores the value on the device and then the teacher flood light transmits the right answer and each device lights up green or red if the answers are correct. It is not exactly the same result as you intended but might be much easier to implement as you don't need to deal with IR collisions of 2 way communication
Do he results need to be recorded to a computer? Another interesting method for this is to put and RGB led and IR receiver on each one. When the student pushes the button it stores the value on the device and then the teacher flood light transmits the right answer and each device lights up green or red if the answers are correct. It is not exactly the same result as you intended but might be much easier to implement as you don't need to deal with IR collisions of 2 way communication