Hoping to get your help, I am new to Arduino, but I think it’s a fairly simple circuit. My relay just isn’t switching. I have replaced it with a separate relay, but same issue.
I’ve attached a Paint diagram of what I have currently.
Arduino Mega 2560 plugged into laptop via USB 2.0.
I have a 5V usb wall wart (old phone charger with repurposed USB-A to USB-C charging cable). This is connected on an NC circuit of the relay with an LED.
The LED is lit (as expected).
However, when my Arduino sends the signal on pin 8 to the relay, the LED remains lit. The relay’s ‘ON’ LED is on during this time, so it definitely receives the signal.
Arduino switches pin 8 HIGH/LOW on 10s intervals, so it’s not switching too quickly to not notice the LED lose power.
Any advice would be much appreciated - I’m truly baffled.