# Bluetooth on the Raspberry Pi Zero W (1 or 2)
The Zero W series has Bluetooth capability because of the Wifi chip on the board.
**Warning:  This is a work in progress!!!**

# Reference
- "Exploring Raspberry Pi" by Derek Molloy pg 537-544
- [Connecting to a Headless Raspberry Pi using Bluetooth](https://medium.com/@tomw3115/connect-to-a-headless-raspberry-pi-using-bluetooth-0e61c05e1b68)
- https://github.com/sorah/bluetooth-getty
- [Use dbus insteadd of sdptool](https://linuxvox.com/blog/bluez-adding-services-attributes-and-profiles-without-sdptool-command/)

# Getting Bluetooth working
1. Login to the pi via a USB-serial port or monitor-keyboard-mouse.  Configuring bluetooth can sometimes kick you off the wifi.
1. Tell `rfkill` to unblock bluetooth.  Perhaps this is a security thing?
```
sudo rfkill unblock bluetooth
```
1. Restart the bluetooth service and check it's status
```
sudo systemctl restart bluetooth
sudo systemctl status bluetooth
```
1. Figure out the address using `hcitool`
```
hcitool dev
```
1. If you have a laptop set to be discoverable, you can check if bluetooth is working
```
hcitool scan
```
1. You can then query that device for what services it offers
```
sdptool browse ADDRESS
```
1. Now we want to make the Pi discoverable to our phone, tablet, or laptop
```
sudo hciconfig hci0 piscan
sudo hciconfig hci name RaspberryPi
```
1. A Serial Port Profile(SPP) is needed for our serial port
```
sudo sdptool add SP
```
1. For some reason, we have to put the bluetooth daemon in compatibility mode.  (True as of 2016-2026 --foley).  Find the line with `ExecStart` and put `--compat` at the end
```
sudo nano /lib/systemd/system/bluetooth.service
```
1. Test the SPP is setup

```
sudo sdptool browse local
```
1. Time to pair it with a device
```
sudo bluetoothctl
discoverable on
agent on
pairable on 
scan on
```
and once you have paired it
```
discoverable off
exit
```

1. If this works, you can install the `bluetooth.services` and `rfcomm.service` files to automate some of this setup.
```
sudo cp bluetooth.service /etc/systemd/system/bluetooth.target.wants/.
sudo cp rfcomm.service /etc/systemd/system/.
sudo systemctl daemon-reload
sudo systemctl enable rfcomm
sudo reboot

```



# Discussion
Apparently Bluez's `sdptool` is now depricated and they are telling people to use this new GATT via `busctl` or `dbus-send`. [linuxvox article on depricated sdptool](https://linuxvox.com/blog/bluez-adding-services-attributes-and-profiles-without-sdptool-command/)