Weekly Update 9-02-17 to 9-08-17

We’re back!

I took the summer off from the project for an internship, but the fall semester has started up so I’m back on Sharkduino!

This week I spent mostly getting things ready for the semester. I moved to a new room, and organized my supplies.

I did get a little bit of real work done too, I realized that our new batteries were wired backwards from our previous ones (ground is on the right of the connector for the old ones, but on the left for the new ones). Luckily we didn’t plug any of these backwards batteries into a Sharkduino, but I did destroy a charger before I realized what was happening. Fixing this problem was easy, but tedious. I just undid the connectors and reversed the wires going into them.

To keep this from happening in the future we are going to be more careful about inspecting new batteries before plugging them in. We are also looking at added reverse polarity protection circuitry to the Sharkduino. At our power level I think this circuitry can just be a P-MOSFET. A picture of my test circuit for that can be seen below.

P-MOSFET test

P-MOSFET test

Blowing up chargers wasn’t the only battery work I did. I am also conducting tests to see if we need to separate the LiPo from the sharkduino system while charging it, or if it will still charge normally while the Arduino is pulling a little current. These experiments are ongoing so I’ll talk more about them when I have results.