ProGrow Update #3
The ProGrow has been exploding with growth over the past few days. Some of the blades are over 6″ now, despite Ozzies constant attempts to eat all of it. The soil started to develop a very small amount of harmless white mold. I assume the mold is due to the consistently high moisture levels. I treated the mold by adding a trace amount of potassium bicarbonate and cinnamon to the soil, and to the water. The mold vanished in less than two days and the grass seems to appreciate it. I also reduced the frequency of automated watering to once every 6 hours at the most, and changed the moisture threshold that turns on the pump. This should help reduce the moisture levels of the soil, to discourage further mold growth.
Batteries
I tested the 18650’s that I had laying around, and only two of the batteries were still functional. The other two seemed to be almost completely discharged and are most likely at the end of their life. I’m going to use these two to create the new battery pack for the system. I still need to test the Macbook battery that I have to see if it’s a potential solution, but I prefer the 18650s due to their profile. I’m still waiting on the charging modules from Aliexpress, and it could still be a while. Once the charging modules arrive, I’ll charge up the batteries and do proper measurements to get an idea of their health.
I am considering moving the system from an Arduino UNO to an Arduino Nano. I believe that it would let me reduce the footprint of the project as well as reduce idle power consumption. I’ve received my SD card module in the mail and intend to implement it into the ProGrow as the next step. I am going to remove the RGB indicator LED in order to free up GPIOs for the SD Card. Ozzie seems to like hanging out right next to the ProGrow. It’s like a grass buffet for him!