This is a funny project that makes our plants “talk” to us. It’s very simple and you can create it in few hours. We use a sensor to read the soil moisture of our plant and a led matrix to dislay how the plant “feel”. You can use an ATtiny85 as a microcontroller.
Step 1: Order Materials
- Led Matrix
- Soil Hydrometer Sensor
- ATtiny85 (Microcontroller)
- 9V Battery
- Battery Clip
- Prototyping Board
- Voltage Regulator L78L05
- 2x Capacitors 10uF 25V
Step 2: Wiring Instructions
To wire your ATtiny85 to your Sensor and the MAX7219, connect the following pins:
- ATtiny85 Pin1 –> NC
- ATtiny85 Pin2 –> Sensor A0 (Analog out)
- ATtiny85 Pin3 –> NC
- ATtiny85 Pin4 –> GND
- ATtiny85 Pin5 –> MAX7219 DIN
- ATtiny85 Pin6 –> MAX7219 CS
- ATtiny85 Pin7 –> MAX7219 CLK
- ATtiny85 Pin8 –> +5V
- L78L05 Pin1 –> Output +5V
- L78L05 Pin2 –> GND
- L78L05 Pin3 –> Input from battery +9V
Don’t forget to connect all the GND together (Sensor, Attiny85, MAX7219). We suggest to connect and the two capacitors to your L78L05 (see the image on the right).
Step 3: Prepare the ATtiny
To program your microcontroller (ATtiny85) you will need an Arduino Uno or a Tiny AVR Programmer.
If you choose an Arduino Uno to program the ATtiny follow the steps below:
Connect the Arduino to the ATtiny as follows:
- ATtiny85 Pin 8 – Arduino +5V
- ATtiny85 Pin 4 – Arduino Ground
- ATtiny85 Pin 1 – Arduino Pin 10
- ATtiny85 Pin 5 – Arduino Pin 11
- ATtiny85 Pin 6 – Arduino Pin 12
- ATtiny85 Pin 7 – Arduino Pin 13
For more detail: Make your plant smile using Arduino
