I'm a structural engineer, so this is a bit out of my element. I've tried to put together my first concept for an Arduino shield, and would appreciate feedback. I'd like to know if it's "workable" before I try to figure out the board layout in Eagle.
It's a dual power supply that can be monitored by an attached Arduino board. That board would then communicate status to the main project board. I have two Max1555's connected to batteries, USB (for main charging) and two solar panels (3.6V, 210ma max). I followed the "mightymintyboost" concept. I tap off the battery voltage to two analog input pins on the Arduino.
3.7V Lipo battery power then feed two PNP transistors. If I have those hooked up right, they should conduct when the base is LOW, so they'll automatically both be on. Then I can use a digital pin on the Arduino to turn one of them off. I could "exercise" the batteries that way, or individually try to monitor their amp-hours etc.
Finally, the combined power supply, now at about 3.3V, goes into two parallel LT1302 voltage boosters. I'm uncertain how those will work in parallel, but they're 8-dip packages so I'm more comfortable with them. Their output is then 5V, and I'm hoping to be able to get 1A total out of it.
See anything stupid?
www.wsengineer.com/powershield.pdf
(Hope I got this link right. It sure is hard to attach files or images here)