I want to put an Arduino-compatible uC, 16 red LEDs, and a battery pack into a construction helmet. There is enough room between the suspension and the hard shell for something like an Arduino Nano (worst case)
LEDs will be paired, and I want to be able to address all 8 pairs separately.
Issues that come to mind:
- Providing enough current for LEDs. (20mA each)
- Batteries to use (weight and runtime)
- Overall size of package / simplicity
I was thinking of using an ATtiny85 and a TPIC6B595N.
How much of a voltage drop can I expect over the TPIC6B595N? Or better yet, where can I find this on it's datasheet?
I was thinking of using 4xAA batteries. For efficiency, should I drive the LEDs directly from the battery, or use the same voltage regulator that the ATtiny85 will be using? Suggestions for a properly sized Vreg?
Suggestions for other battery packs?