Bicycle
ok, this is presently just a stub
is about charging on-board-batteries of xo1 using a bicycle hub dynamo
am presently on building the software-environment to use xo1 as a navigation-tool
powered by a standard bicycle hub dynamo
depending on the power-consumption (not yet clear) it allows:
EITHER being constantly powered-up (best in display-reflexive-mode(backlight LED off), and as a tablet: attached to the bars
OR only being partly powered-up (wait for recharge...)
(BUT if you got several persons riding the same track you can ask them to serve as your "volountary power slaves": as it is clear at least TWO persons deliver enough energy for constant ON-time: the other person charges another XO1-battery (not yet tested!, suppose is difficult because of smart-batteries??: them know their charging-status attached to a XO1 and being charged by this / vs charged just by a hub-dynamo???) i had opened the battery-pack: (LiFe-batteries) and modified the case so that i can neaty feed in just single 18650 LiIon-cells... -maybe these can be cahnged...?! is yet to be tested!! at any rate: if you plug in a 12-18V external-batteries-pack at the external-charging adapter you can easily power/recharge the XO1...)
the hub-dynamo needs just a rectifier (4 diodes) and a capacity or a smaller battery (eg 3 (maybe used, from scrap, batteries from any portable phone...) revived (not TOO high inner resistance, though)) LiPo-batteries (BUT YOU MUST BE CAEFUL OT TO OVERCHARGE THEM: DANGER OF FIRE/EXPLOSION...) to give rather constant voltage: it delivers around 4-6 Watts (plus possibly added a capacitor inline (if you go for maximum power/voltage at lower speeds already (as the hub is a current-source with a large inductivity you can compensate... -but this limits the possible output even at higher speeds, so a switch would help...)