I've started using a self-defined set of color codes for my Arduino projects and I thought that I should ask if there are already some color codes in general use.
I bought six spools (1000 ft/300 meters) of wire-wrap AWG30 in black, red, orange, green, blue, and gray.
I have standardized on BLACK for ground/earth/0.0 volts and RED for Vcc (the main AVR voltage on the Vcc pins). I've assigned blue to SCL and green to SDA lines on the I2C/TWI/wire.h connections. ORANGE is for any power voltage that is not Vcc, i.e. the Vin +9V (or +5V USB voltage if the AVR Vcc is +3.3V).
If there is a different standard in general use for these lines, then I'd like to know before getting too deep into my own color assignments.
The color codes are used for:
> Schematics. I do a simple cut_and_paste of old OrCAD symbols on a black/white image in PhotoShop/PaintShopPro/GIMP instead of using Eagle or a commercial schematic-capture program. Works for me. After the Black/white diagram of the circuit, I overdraw the buses and important traces in color in software or with colored pencils on paper print-outs.
> Wire-Wrapping and point-to-point soldering on the prototype board. Black=gnd; red=Vcc; blue=SCL [I2C], SCK [SPI] ; green=SDA [I2C,SPI], reset; orange=ChipEnable (TFT); grey= RegisterSelect
> Plastic test-clips for custom hardware tools (like I2C sniffers, MIDI, and RS232 monitors).
> Lay-out and part-placement drawings. Scans and photos of circuit-board prototypes under development. When reverse-engineering a printed circuit board, I scan the board with 800 dots/per/inch resolution. Most traces will be a slightly different shade of the (usually green) solder-mask color. I use paint-fill with a tolerance setting that allows the image of the trace to be paint filled in a different color. This lets me see at a glance the entire Gnd, Vcc, or other individual trace network on the scanned image of the PCB.
> fritzing. Standardized Arduino parts-layout-wiring software.
> timing charts.
I know that the resistors have a color band code that (roughly) follows the rainbow: black/brown/red/orange/yellow/green/blue/violet/grey/white. And there are old capacitor color codes that were sometimes followed on 20th-century electronic devices.
Are there any standard AVR/Arduino standard color coding systems that I might not be aware of?