This weekend I thought I'd revisit the VoCore Alpha modules. The Alpha version needs a small modification - remove one of the 0402 capacitors and solder it between another surface mount capacitor and resistor.

My first attempt didn't seem to work ( probably because I fried the poor capacitor ). I had  spare 0603 in the right value, so I tried to squeeze that in. The result at 9pm Sunday night?

It's alive!!!!!!!!

I might be able to actually have something working by the end of this competition now!

On the solar side of things, I have a few of the small solar cells that I'd bought off eBay. I don't have any tabbing wire to join them together, but I did find a small piece of brass shim in the shed. Turns out that brass shim tins very easily, so I cut it to the width of the electrode in the middle of the solar cells. I then used a flux pen to coat the electrode on the solar cells (solder doesn't stick easily to the white coloured electrodes without some help, plus the cells don't like high temperatures). I joined 4 in series, top electrode to the bottom of the next one, before I ran out of shim!

This gives me just over 2V and 400ma. Not quite enough, but it may do for testing. I'm going to find an old photo frame to house the cells for the time being.

In other news, I've been getting to grips with the Linear Technology LTC3105 datasheet, in order to work out the specifics of the components I'll need to acquire to make the power supply and battery charging board. I'll probably do something like the reference schematic, where the output of the LTC3105 charges a battery, as well as providing the input for the VoCore module. I should have an Eagle file soon!