Solar test #9 is still going strong.
For reference, the solar test started Sunday, 2018-06-23 at about 3:00 PM, with about 80-90% charge on the batteries. I put a Pro Mini into the works to shut down the Raspberry Pi at night. Monitoring the blue lights on the chargers, I am getting a full charge on all but one battery by about 10:00 am every day. The one never seems to get a full charge. My thoughts on that are as follows:
- Faulty charger, but I have replaced the one on that cell.
- Bad battery.
- That battery is performing better than the others and is taking up most of the load. If so, it’s always “charging.”
- I have no idea.
I am going with #3 at this point until I learn otherwise.
I have not posted the information regarding how to build this in detail yet. Because I am working on #10. #10 will be published with all the information for you to build your own. The most significant difference is I am changing out the Pro Mini with the Adafruit Trinket M0.
The M0 has a few advantages over the MiniPro. The biggest is that it has a USB port, and it runs CircuitPython. If you have not played with CircuitPython yet, you need to get one of the boards and try it out. When you connect the board to your computer, it mounts as a drive. All you need to do is edit the main.py file and save it. The board sees the file has changed and reboots all by itself. It’s great.
Finding this board and the drive mounts on the Pi sent me in a new direction. I will now have the Pi connected to the Trinket M0 via USB but without the power pin connected. I will connect the power pin of the USB on the Trinket M0 side directly to the charge controller.
Today I started the sandbox unit. The sandbox will be built exactly how the real rover is built. It will stay in the backyard or on the workbench. The sandbox rover is being built as version 10 of the solar test. I don’t want to stop #9, I want to keep it running for as long as possible. Next weekend I will put #10 out and see how it performs.
One thing I did learn, program the M0 before connecting it to the Pi. It puts it in a startup/shutdown loop.