I'm trying to connect a XS3868 Bluetooth module to an Arduino. This is what the module looks like, the picture includes the pin names. I also found the following diagram online that explains how to wire it:
There a couple of symbols in that diagram that I don't understand though:
- What does the symbol indicated in red and the 47u or 220u next to it mean?
- What is the part of the circuit indicated in blue trying to do? Why is there a capacitor?
Thanks for your help!