My module flashes with blue LED once per 2 seconds. It behaves this way when TX and RX are completely disconnected (no jumpers$ AND when I connect jumpers for TX and RX (pins 0/1 from Arduino, powered by battery to prevent serial conflict with USB).
Not only is my shield not discoverable; it does nothing besides flash blue LED.
What diagnostic codes or info can I pull from the shield to tell me possible causes? Any obvious culprits?