###Using BLE RN4871
####(In process of editing and adding material 11/28/18)
This is a bluetooth module that can do several things. So far, I have followed Neil's example to connect it to a phone, and
have programmed two modules to connect with each other. I have used them as wireless serial connections.
#### Designing board.
I started with [Neil's hello-world board](http://academy.cba.mit.edu/classes/networking_communications/RN4871/hello.RN4871.ftdi.png)
with some modifications:
- Add an LED to indicate 3.3V power, and one connected to the p_02 pin of the module to indicate operation of bluetooth device.
- [link to Eagle library](./RN4871-V_RM118.lbr) which has symbol and footprint.
#### Connecting to module with computer.
[This tutorial](http://www.martyncurrey.com/arduino-with-rn48701/) got me started.
#### Communicating with phone.
---
[user guide](http://ww1.microchip.com/downloads/en/DeviceDoc/50002466B.pdf) has commands. Very useful and readable.
#### Connecting two modules to each other.
Mounted a second module. Woke up with services 00. See user sheet: needed to give it command "SS,C0".
This one now reads and writes to/from phone.
Look at bonding, and whether that makes it easier to connect two devices.
- Put in command mode. Make sure service is C0.
- connect using c,0, {mac address}
- bond using b.
- now when both are cycled:
- put in command mode
- send command "c CR"
- should see "Stream_open" and devices send trpansparently to one another.