miniLOG - precision standalone voltage logger

I'd like to introduce my latest project. It's a precise standalone voltage logger that saves the logged data to an SD card. I call it the miniLOG, because it's small and well, it logs stuff...

The idea first came to me when I was thinking about some small product that I could sell. Either as a kit or as a ready product. The idea of having a small, portable voltage logger seemed pretty cool. However, I like to think that for a product to sell, it should have some unique little aspect to it. It's hard for a better unique aspect than precision.

I didn't want to put any complicated analog circuitry on the board because from the very idea it was supposed to be small. I thought that a simple 12bit ADC would be enough. I added 3 more microcontroller ADC channels just for the hell of it. All input voltages are divided by 10 with precision 0.1% voltage divider resistors. So the miniLOG has 4 voltage logging inputs, one of which is a high resolution 12bit input.

This is the first part in the miniLOG series. I hope to be updating it every now and then.

Here's a little sneak peek of the PCB

Peace.