Automatic home plants watering system (under $10 bucks!) - Arduino Nano v1

thingiverse

This is an affordable home plants watering system under $10. It measures soil humidity, decides when it's dry enough, and turns on a water pump using a solenoid or a 5-liter bucket. I coded this project as my first time with Arduino, so don't expect perfect code. No soldering is required, but the control box is larger due to the wires. I tried a smaller version, but it didn't fit all the components. Here are the necessary parts: * 10 M3 nuts * 1 Arduino Nano ($2.79) - https://www.aliexpress.com/item/Nano-CH340-ATmega328P-MicroUSB-Compatible-for-Arduino-Nano-V3/32572612009.html * 1 Step Down power supply ($1.09) - https://www.aliexpress.com/item/Free-shipping-1pcs-XL4005-DSN5000-Beyond-LM2596-DC-DC-adjustable-step-down-5A-power-Supply-module/32730909898.html * 1 Relay module ($0.65) - https://www.aliexpress.com/item/KY-019-5V-One-1-Channel-Relay-Module-Board-Shield-For-PIC-AVR-DSP-ARM-for/32358134833.html * 1 Humidity sensor module ($0.58) - https://www.aliexpress.com/item/Smart-Electronics-Soil-Moisture-Hygrometer-Detection-Humidity-Sensor-Module-For-arduino-Development-Board-DIY-Robot-Smart/32562744759.html * 1 Mini Protoboard ($1.98, 5 pieces) - https://www.aliexpress.com/item/5PCS-SYB-170-5-Colors-Mini-Solderless-Breadboard-Prototype-Experiment-Test-Protoboard-170-Tie-Points-For/32671297865.html * 1 Arduino male jumper wires ($1.00) - https://www.aliexpress.com/item/40PCS-20cm-male-to-male-2-54MM-1P-1P-Dupont-cables/32648521256.html * 1 Arduino female jumper wires ($0.67) - https://www.aliexpress.com/item/Dupont-line-20pcs-10cm-2-54mm-1p-1p-Dupont-cables/32807872201.html You'll also need a 12v power supply, which you'll cut and connect to the protoboard using male jump wires. Then, connect it to the DC-DC Stepdown power supply and adjust it to 5v. Use male and female jump wires to directly power the Arduino Nano and Relay board. Do not connect the humidity sensor directly to the 5VCC, as many sensors suffer from premature wear when powered on constantly. Instead, use digital IO from the Arduino to power it. There's a plastic pin on the case that fastens the pump and power supply wires with hallermann ties. The idea is to turn on the sensor using digital IO, measure humidity using an analog input, and if it's greater than 650, the soil is very dry. Another digital IO makes the Relay board give 12v to the pump. Then, it compares if the humidity has changed at least 10%, and tries 20 times to make the soil reach 400 units of humidity. If it fails, maybe the water has run out or there's a problem with the pump, then the program goes into an infinite delay. The sensor must be somewhat close to the water hose exit. I've used some delay to give time for the water to penetrate into the soil and reach the sensor. Lower delay times between "pump and measure" gave me very wet spots, so there's almost 10 seconds between cycles. Pump must be submerged, so it must be placed under the water vase to stay always wet. I've been using this for over a month, and it uses 5L of water for 1.5 weeks in a big vase of 80x40x15 cm. PS: This project was taken down by Thingiverse without reason in 2018. This is just a re-upload!