Arduino schematic

I’ve just started playing with the Arduino module. I’ve had experience on uno/mega/DUE and teensy 2/3 stuff. A couple of questions on the schematic:

  1. what is part number or specs (ppm) for crystal? (Leonardo uses crystal rated at 30 ppm)

  2. schematic shows IO6 and D8 tied to Vcc through some capacitors and notation says “for DataCom” – what does that all mean??

With a multi-meter and breakout module I ran some power tests on the Arduino module.

just running blink (4s interval) with bargraph on d5: off 33ma on 57 ma

power tests:

5v@16MHz (TX/RX LEDs off) 
 run  26 ma
 IDLE  19 ma
 powerdown  0.68 ma 
   run @8mhz 17 ma    @4mhz  13 ma

see http://gammon.com.au/power

For power consumption of littlebit modules see

-------------------------- Edit 12/13/14 ---------------------------
From the eagle files at
https://github.com/littlebitselectronics/eagle-files
the littlebits arduino 16 MHz crystal is a TXC 7B series spec’d at 30ppm.
On my module, I measured 2 ppm using NTP or a GPS PPS pulse, see
https://github.com/manitou48/crystals/blob/master/crystals.txt

Hello manitou,

  1. If I recall correctly our crystal is also accurate to 30ppm.
  2. Those two pins you see under DataCom are allocated for potential future development by us.

Those current measurements look like feasible. Figure about 5mA per LED on the bar graph. If you are measuring after your power source then you can attribute the rest of the current to the Arduino module. You might see some different current ratings than you would with an Arduino Leonardo due to some external circuitry differences.