As you can see in the schematic all three TC74 sensors have their SDA and SCL pins connected in series to pin A4 and A5 on the Arduino board. The two 4.7K pull-up resistors must be used when using I2C ...

Adding a photoresistor (light sensor) and a thermistor (temperature sensor) and connecting them to a programmed Arduino gave me a gadget that monitors the environment of a single plant. You can ...

I made this project because I wanted a way to automatically control the speed of a DC fan according to the temperature read by a LM35 sensor. I had a few problems with the PWM part mainly because the ...