Here's some pics from those events. If you recognize your child (or yourself) and would like the picture removed or credit for the pic, just let me know.
|Inspiration meets Curiosity. Thanks to the JPL Spacecraft 3D app, you can do augmented reality with JPL spacecraft.|
Once the demonstrations were done, I decided to look into how the battery was being charged by the solar panel. I quickly realized that it wasn't. The solar panel is capable of about 200 to 300 mAhs. Just sitting there, the rover draws about 200. So the solar panel really wasn't doing much. The nice thing is though, that Inspiration can sit for about 4 hours before dying.
I decided to go back to the 2 battery system where the rover drives on one battery while charging the other and then switching as one battery is drained and the other is charged. Theoretically it should keep Inspiration running as long as there are sunny days. However, I found out the code for such a change over can be tricky. Also, the discharging battery drains faster than the other can be charged so there ultimately the rover would be dead after about 24 hours.
Here are some tests that I did while at work a few weeks ago. I was trying to get the code right and also collect data on how long it takes to charge and discharge.
|This was the setup I had going outside of work and I monitored the battery voltages from my desk|
|Unfortunately the sun wasn't out all week so I had improvise with this setup under my desk.|
|First test showed one battery powering the Arduino and Xbee shield and the other being charged.|
|This test showed what happened in my code when the 2 batteries became equal in voltage.|
|This was a successful test of the batteries charging and discharging.|
After these tests I decided redesign the power distribution system and get a few new things to help with better charging capabilities.
A new relay. This relay uses a lot less power to actuate the switches and each relay can switch 2 circuits at once. This should work well for the 2 battery system.
|Inspiration in its "Launch" configuration|
|Made a foamcore box to put it in for shipping.|
|And the final package complete with duck tape handles and ready to be stuffed in another box and shipped.|