I bought this relay module and I tried connecting it to my raspberry pi. I attached the Vcc (one next to the inputs) to the 5v rail of the pi and gnd to gnd. I attached the input pins to various gpio pins and when I try and switch it on, it doesn't work. I followed this question and checked my module and all the tests passed. What should I try or should I just request a refund?
All answers appreciated!
EDIT: Powering up relay with JDVCC jumper on, and connecting each one of the input pins to ground does work. My power source is a 5v power supply up to 2 Amps. The states are switched on this relay, makes sense.