I am building a hand held portable raspberry pi. I have just plugging the battery in and using the thing, but I want to make the battery completely part of the unit without the need to unplug it when I am done. so here is what I want to do completely:
1. Have a switch to be the master on/off switch.
2. when the unit is plugged in to a dc power source (wall wart), you will have a switch that will let you to select between powering the unit or charge the unit
3 .Have led indicators for charging, unit powered by battery, unit powered by external
I already have the Pi working with a 7.4v battery for the last month. It is using a switching regulator that works til about 6.0v which is pretty much dead for the battery. The battery already has a built in charging PCB so all I have to do is apply at least 7.5 volts and it will charge with no issues.
below is a draft for the power circuit. Logically, here is how I think it should work:
Plugged In Master On/Off Charging/Wall power Status
Yes On Charging Charging
No On Charging Battery Powered
Yes Off Charging Charging
No Off Charging Off - Does Nothing
Yes On Wall Power Wall Powered
No On Wall Power Battery Powered
Yes Off Wall Power Off - Does Nothing
No Off Wall Power Off - Does Nothing
Here is the circuit how I have it laid out right now in fritzing:
So my questions are:
a. will this work as I expect it
b. How do I add in the indicator led's
