Today I played with what I thought to be a buck-boost converter. Turns out when I bought it I didn't read the description very carefully. It is actually just a buck converter and can only lower voltage. This will not work for my application, but does give me a piece of hardware I won't feel bad if I destroy. What am I going to do with/to it?
In addition to ordering the converter, I also picked up some MCP42100 digital resisters. They allow the resistance to be set over an SPI bus interface. The buck converter I picked up has two potentiometers: one for voltage and one for current. My plan is to replace the potentiometers with the digital equivalent. This should allow me to control voltage and current from the Arduino. A very cheap Arduino controlled variable power supply.
The purpose? The first step is just to see I can make it work. If it does work, I want to do this with a buck-boost converter and turn this setup into a smart battery charger. Used in combination with maximum power point tracking (MPPT) and an optimum charge algorithm for lead-acid batteries, I should be able to make a superior to the one I am using—and hopefully eliminate some of the strange problems with measuring current I have encountered.
Pictured is me at Governor Dodge State Park. Picture by Lisa B.