Hi,
I am using an Arduino to control the light outside my house in the staircase. I am using a pir senor as an input on pin 2 and a relay on pin 16 to switch the lamp. My question is should I tie these Arduino pins to 5V with a 4K7 resistor and then connect to the sensor/relay, or should I connect them without the pull-up resistor?
I think I should use a transistor to switch the relay as the coil resist ensue is about 150 ohms.
Your thoughts are welcome.
Regards for your time.
