- Custom Development
Some FlexSEA boards come with onboard Bluetooth, and most can support an external module on their expansion connector. In all cases, a Microchip RN42 pre-certified Class 2 Bluetooth radio is used. Using the Serial Port Profile (SPP), it is seen as a COM port on your computer (same deal as with serial-over-USB).
Before starting this guide, please make sure that:
You are now ready to use this module with the GUI.
Using the GUI with Bluetooth is almost the same as with USB. You start by opening a COM port, and you can stream sensor values and send control commands. The only difference is that with Bluetooth you should always be in Auto mode.
Normal mode: for every packet the GUI will send a Read request, and the circuit will send a Reply packet. If you are streaming at 100Hz, it means that you'll be sending Read packets every 10ms, and receiving replies shortly after. The packet rate will be 200/s.
Auto mode: the GUI will send one special configuration packet telling the circuit to send replies at the requested frequency. Streaming at 100Hz means a packet rate of 100/s, and unidirectional radio communication.
Using Normal mode at speeds above 30Hz while on Bluetooth can lead to communication crashes. Always use Auto and you'll be able to reliably stream at 200Hz.
After you open the COM port we recommend that you wait 10-15s before starting to stream at high-speeds.