Create schematics for I/O Expander (Halloween controller)
I need an "I/O Expander" that should use the Parallax P8X32A Propeller chip (http://www.parallax.com/tabid/407/
The basic design can come from something like this board: http://www.parallax.com/tabid/768/
I'm thinking something like this:
1. Power supply input on-board, provide both 3.3 and 5 v
2. 8x digital inputs (3.3 volt, but 5 volt tolerant). Isolated, but don't have to be opto-coupled. Should have feedback LED.
3. 8x digital outputs (low mA, 3.3 volt). Should have feedback LED.
4. 2x A/D input (note that the propeller chip does not have an A/D converter on-board, this has to be solved with external components). Used for analog sensor reading, not audio.
5. 4x analog inputs with level comparator (can this be made with adjustable level?)
6. USB port on-board (embedded "Prop Plug": http://www.parallax.com/Store/Micr
7. 2x relay outputs (relay onboard, small, low voltage, but isolated)
8. 4x LED outputs (can be used to control using PWM, up to 0.5-1A/output, not that exact)
9. 1x DMX output (RS-422, bit-banged by propeller)
10. 4x mosfet outputs to control external relays, etc. See https://www.sparkfun.com/products/
The job is to create a schematic and PCB layout in Eagle PCB CAD using good electronics design practices. Note that the schematic should include a Propeller chip, but no software development is required.
1. Clean Eagle Schematic file
2. Clean PCB layout file
3. Parts list from Digikey or Mouser
The schematic will be reviewed by electronics engineer.
Please note that this is for a hobby project and I don't have a lot of money to spend on it (about $100 or so).
If you're interested then please let me know how long you estimate it will take to complete, and include sample schematic and pcb layout (pictures) that you have previously created.