Greetings,
I've made this great digispark circuit and have been trying to minimize it's power consumption (b/c it will be running off a battery). I've already got the sleeping thing down (though it sleeps for nearly 9 seconds rather than 8
), and destroyed the power led (while trying to unsolder it).
At this point, I have managed to reduce the current draw to about 4.7mA (while sleeping), but this is quite far from the micro/nano amps that I see in some of the arduino-world.
Following a hint that the power regulator may be consuming much of the power, I tried powering the board directly from the 5v line, but found it's consumption to be 20mA (!)... then tried undervolting it to 3.3v and found it to be 10mA (!?).
My best guess is that the regulator does not work well with "back pressure" from the 5v line, but I thought this was an expected operating mode?
Also, I have read a that disabling the brown-out detector (e.g. when sleeping) can save some juice, but when I tried that (in software, not fuses) it *increased* the amps from the baseline to 8mA. So I imagine that the ATTiny85 on my digispark is not one of the revisions that can do that (docs say rev C & newer), or maybe I'm doing it totally wrong.
Disabling brown-out detector while sleeping:
http://forum.arduino.cc/index.php?topic=83826.0Can anyone provide some pointers on the two problems above? or how I might (or if I can) experiment with the "fuses" on the attiny to disable the brown out detection?
