The sketch for this project can be downloaded from my GitHub page here.
In an earlier post on using the HM10/CC41A BLE units a comment was posted asking about using this Bluetooth with an Arduino Pro Mini. I purchased a Pro Mini recently and it arrived a few days ago. once I had it up and running I connected the Bluetooth unit.
The Tx and Rx signal pins were connected to the Pro mini through a bi directional logic level converter (Bluetooth Tx to Arduino Software Serial Rx pin and Bluetooth Rx pin to Arduino Software Serial Tx pin) but I used 5 volts to power the Pro Mini. I initially tried using 3 volts but this was unsuccessful. As the Pro Mini does not have a 3.3 volt pin I used a logic level converter with a 3.3 volt regulator.
I uploaded the sketch I use to test Bluetooth units that can be found on my GitHub link at the top of this page, switched the Serial Monitor on (9600 baud, NL and CR selected) and typed in AT . The reply OK was received showing that the Pro Mini was talking to the Bluetooth unit. I typed in AT+BAUD and received the reply BAUD=4.
This short test shows that the Pro Mini can work with the CC41A BLE unit with no apparent problems.