My final project takes care of plants. It came out a little different from what I imagined when I pitched the idea in class.
First of all, I went to Canal Plastic to buy a half-dome plastic, but they didn’t have it and they were very rude, so I decided to take my business elsewhere. I ended up buying a birdcage from a friendly hardware store near my apartment.
It’s not exactly how I planned it, but I am happy with this. And I like the idea of plant trapped in a birdcage too.
Second of all, instead of making a gravity water system with a water valve, I decided to use a water pump. It kind of complicated things, but I will talk about it later.
I started with making the soil moisture sensor work. I picked up a moisture sensor from Tinkersphere. I won’t be able to connect the arduino to my desktop all the time, so I used a LCD to show the soil moisture instead of using the serial monitor.
I wanted arduino to water plants only in the evening, but like I said, I won’t be able to connect arduino to the desktop (to get time), so I had to get a RTC (real time clock), so I went back to Tinkersphere again. RTC has its own backup battery and now arduino can track time even after being disconnected from the computer.
Next part was to control the UV light. I ordered Power Switch Tail as it was suggested in the class. The power switch tail came with a manual (unlike other parts you get for arduino) and it was pretty self explanatory.
At 3pm, piezo speaker plays “Twinkle Twinkle” and the light turns on. It turns off at 8pm. Except for Sunday because I like to sleep in. I ended up planting California Bluebells, and they like shades. So, only getting UV light from 3pm to 8pm is good for them.
So far, so good. Now I’m trying to use a water pump and that’s when things got confusing. I know we learned how to use 12V motor in class, but I forgot how and was really scared to fry the USB port. I went to Tinkersphere again (the cashier remembers me by now), to get a transistor and diode to protect arduino from the backlash. I also had to get a relay, and that I didn’t know how to use and couldn’t find a useful information online. So, the cashier at Tinkersphere helped me. Anyways, I tested the water pump and it worked.
At 7:30pm, the plantsitter checks if the soil is dry (soil moisture less than 50%), the plantsitter will play “Twinkle Twinkle” again and water the plant. If not, it doesn’t do anything. I did some testing and leaving the pump on for 20 seconds was the best. It’s enough time for water to travel through the tube, waters the plant, but not too long so it doesn’t overflow the pot.
Here is a video of the plantsitter watering the plant after mounting it to the birdcage. Originally I had the water on the floor, but the pump wasn’t strong enough to push water all the way up, so now it’s on the shelf. The plastic container doesn’t look very nice, so I am planning on getting a nice glass to put water in.
I’ve added some moss for the look.
Now it’s finished!