Hi Steve,
You are sending a wrong data, when the QN9020 received wrong command. it answer ECFA0100. So, be sure that you are sending 0xEA not the ASCII value.
Note:All commands should be transmitted with the least significant octet first (Little Endian).
Start Advertising - EA 01 05 01 30 00 64 00
Then you can receive some data. ED 01 01 01
ED = Event MSG_TYPE
01 = MSG_ID Advertising command complete event
01 = The length of Params.
01 = Data value 1
For more details for the other commands please take a look QN9020 Easy ACI User Guide
Hope it helps. Let me know if you still have problems
Best Regards,
Mario