Dear ITEAD Studio Stuff,
I recently purchased from AMAZON your 3G Shield, it was working all fine with power supplied from USB port of my LAPTOP, until I decided to run it with Arduino MEGA 2560 and using a BATT (11.1V 3200mAh) where now the SIM5216E keeps telling me this error message "+CME ERROR: SIM failure".
Can you help me fixing this issue?
You'd better submit your question to the support desk. Engineer will reply to you one-to-one.