When few weeks I wrote how to solve a problem of broken USB port in Flip32+ flight controller, I suggested that one of the solutions is adding a serial Bluetooth module to provide wireless connection with a bord. And telemetry. Excellent news is: this is pretty simple and cheap.
What we will need:
- Flight controller with soldered UART pins,
- HC-06 serial Bluetooth module, costs below $5 when imported from China,
- USB-to-serial module, for example FTDI FT232RL. This is needed to configure HC-06 to use 115200 port speed,
- 4 wire female-to-female golpin cable.
First of all, you have to configure HC-06 to use proper baud rate. In case of Flip32 it would be 115200 bps (bits per second). For this you will need FTDI. Connect it by crossing RX and TX lines like that:
HC-06 FTDI GND GND 5V 5V RX TX TX RX
Plug FTDI to PC’s, install required drivers, and connect to correct COM (or /dev/tty.* in case of Linux or Mac) port with speed 9600 bps. This is default value of HC-06. If connection failed recheck wiring and try different baud rates.
At this step you will of course require software to make a serial connection. There are many choices. For example:
- Linux and Mac usually has preinstalled screen command that does that. In my case (Macbook Pro) syntax was:
screen /dev/tty.usbserial-A50285Bl 9600
- In case of Windows machines you can use excellent Putty
After establishing connection with HC-06, we need to send some AT commands to configure name, baud rate, pin and other:
ATif you will see OK after this command, you setup is running correctly,
AT+NAMEFlip32will set name of BT module to Flip32,
AT+BAUD8sets baud rate to required 115200,
AT+PIN1234sets PIN to 1234,
AT+ENABLEIND0disables indication print
The only problem here is that you can not just type them. BT module will expect that each command will enetered very fast (AFAIR mas 1s between letters). So the best option here is to open text editor, type commands there and then copy them one by one into serial software.
Now you can disconnect BT module and connect it into Flip32. I’ve described how to solder UART pins in previous post, so please refer to it. Cross TX and RX lines between Flip32 and HC-06 and you are good to go.
Power up Flip32 FC, red light on HC-06 will start to blink, that means it is ready to accept connections. Pair your PC/laptop with Flip32 (it will be visible under the name you gave it using AT+NAME commant) and chosen PIN (the one you entered using AT+PIN command). After pairing open Cleanflight configurator, choose COM port (in my case on Mac it will be was /dev/tty.Flip32-DevB), select 115200 speed and click Connect. That’s all. You have remote access to your multirotor drone flight controller. That makes configuring it much easier.