I download the sample code into Arduino UNO.
First time, I powered the Arduino by USB. the RFID shield works fine, the search light was on.
However, when I change to battery jacket, it’s not working. Only power light was on.
Can anyone help me? 
I download the sample code into Arduino UNO.
First time, I powered the Arduino by USB. the RFID shield works fine, the search light was on.
However, when I change to battery jacket, it’s not working. Only power light was on.
Can anyone help me?