Electrolyte Crave-o-Meter

thingiverse

We all know that plants are desperately hungry for electrolytes, but how can you possibly gauge the extent of their desperation? Now you can, with your very own Electrolyte Crave-o-meter! It's a ridiculously simple Arduino-controlled sensor that changes the LED from red (dry) to green (moist) to blue (saturated), depending on the range of values you input in the Arduino sketch. You probably won't be able to get any more colors out of it, but I tried at one point and just wasn't good enough to see the difference anyway. I built this a couple of years ago, so if some of the parts are outdated, I'm really sorry about that. I'm including the original .SLDPRT and a .STEP version if you want to make changes to fit other components. I designed the switch port for mine specifically for a switch that I scavenged and liked, so one of the .STL files has that removed in case you wanted to maybe drill out one yourself. I also designed it for thread inserts, but if you don't want to bother with those there's a version that just has little pilot holes instead. I think this would be an amazing PETG candidate, my first print was PLA and warped significantly after years out in the sun. My reprint is ABS, but I had a really hard time keeping the box from eventually warping with the long print time. No supports needed for the box. The Nano fits nice and snugly, but there's a little cover to secure it in place if you need. Arduidno sketch is included! Parts used: - Arduino Micro - 6V 2W solar panel - Solar Lipoly/LiIon charger - Tiny 3.7v 500mAh Lipo battery - 5V boost/buck converter - Soil moisture sensor - 10mm RGB LED - One red and one green 3mm LED - (x4) 8 mm long M3 x 0.5 mm screws - (x4) M3 x 6mm x 5mm knurled thread insert - (x12) 5mm long M2 x 0.4mm screws - (x12) M2 x 3mm x 3.5mm knurled thread insert