The Chumby Hacker board doesn't take a lot of power on its own but adding goodies can really boost up the draw, here are some things to look out for.
- The main system itself (processor, RAM, SD card) draws 200 to 300 mA depending on how hard its thinking
- The USB hub draws 100-200mA (not including power to the USB devices) depending on how many ports are active
- Having a speaker plugged into the 2W output adds as much as 300mA (louder speakers = more current draw)
- Charging an attached Lipoly battery will take another 500mA max
- Plug-in LCD (we dont have one yet but say it existed) will draw 100-200mA depending on make and backlight brightness
Under no circumstances should you power the device with anything higher than 5V, you will destroy it!
The board can also use a standard 3.7-4.2V lithium ion/polymer battery for power. The board even has a built-in lipoly charger! It is activated by default and if you plug in a Lipoly battery you'll see the kernel recognize it and start charging at up to 500mA.
The Lipoly breakout is a JST B3B-EH-A connector on the same side as the power and A/V jack, next to the single USB port. To connect, use a 0.1" or 2.5mm spaced female socket - the official one is JST EHR-3 and crimp the matchingcrimps on a red, yellow/white and black wire (28 AWG, stranded is best). Slip in the crimped wires so that the board markings match up such that red is +, T is yellow, and - is black. The markings are on the opposite side of the PCB
If powering from a lipoly, the chip will boost it to 5V to supply power to one of the USB ports (the top one, on the same side as the power jack) but not to the other two. There is a fourth USB connection on the header where I2C and other DIO pins are - this one IS also powered by the lipoly boost system.
The lipoly is also used for the RTC backup! Any lipoly battery, when charged, will let the RTC run for years.