bluetooth-gateway-study-guide

Debugged version of the Python Bluetooth Internet Gateways Study Guide from Bluetooth SIG V2_0_1

A web BLE gateway based on an embedded HTTP server (Apache2) and WS (Websocketd) with my added MQTT adapter

Tested with ROCK-3C and Silicon Labs Thunderboard Sense (SLTB001A) & Thunderboard EFR32BG22 (SLTB010A)

OS Installation

Get latest Debian XFCE image - CLI not working - tested with rock-3c_debian_bullseye_xfce_b42.img.xz

Set systemd default target to CLI: sudo systemctrl set-default multi-user.target

Update system:

sudo apt upgrade

Reboot sudo reboot

---

Software

Install Paho-mqtt in venv:

sudo apt install libdbus-1-dev libglib2.0-dev libcairo2-dev libgirepository1.0-dev

Install Mosquitto:

Setup listeners:

# Enable settings by listener
per_listener_settings true
# Allow anonymous access on port 1883
listener 1883
allow_anonymous true

Restart:

Copy gateway code:

cd bluetooth-gateway-study-guide/implementation/solutions/peripherals/gateway_mqtt_no_security

Create virtual env:

source venv/bin/activate

Install packages into venv:

pip install dbus-python

pip install PyGObject

pip install paho-mqtt

---

Using Bluetoothctl to connect and identify characteristic path

Open a separate Terminal and start Bluettotctl:

[bluetooth]# scan on
Discovery started
[CHG] Controller 50:5A:65:27:45:D8 Discovering: yes
...
[NEW] Device 9A:61:DA:87:D2:C4 Nano33BLESENSE

[bluetooth]# connect 9A:61:DA:87:D2:C4 
Attempting to connect to 9A:61:DA:87:D2:C4
[CHG] Device 9A:61:DA:87:D2:C4 Connected: yes
Connection successful
[NEW] Primary Service (Handle 0xa504)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service0006
	00001801-0000-1000-8000-00805f9b34fb
	Generic Attribute Profile
...

[Nano33BLESENSE]# menu gatt
Menu gatt:
Available commands:
...

[Nano33BLESENSE]# list-attributes 
Primary Service (Handle 0x17f0)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service0006
	00001801-0000-1000-8000-00805f9b34fb
	Generic Attribute Profile
Characteristic (Handle 0x0001)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service0006/char0007
	00002a05-0000-1000-8000-00805f9b34fb
	Service Changed
Descriptor (Handle 0x0000)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service0006/char0007/desc0009
	00002902-0000-1000-8000-00805f9b34fb
	Client Characteristic Configuration
Primary Service (Handle 0x819c)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service000a
	0000181a-0000-1000-8000-00805f9b34fb
	Environmental Sensing
Characteristic (Handle 0x7c60)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service000a/char000b
	00002a6e-0000-1000-8000-00805f9b34fb
	Temperature
Descriptor (Handle 0x0000)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service000a/char000b/desc000d
	00002902-0000-1000-8000-00805f9b34fb
	Client Characteristic Configuration
Characteristic (Handle 0x9070)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service000a/char000e
	00002a6f-0000-1000-8000-00805f9b34fb
	Humidity
Descriptor (Handle 0x0000)
	/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service000a/char000e/desc0010
	00002902-0000-1000-8000-00805f9b34fb
	Client Characteristic Configuration

---

Testing

Start mqtt_client in venv:

/home/rock/gateway_mqtt_no_security/venv/bin/python /home/rock/gateway_mqtt_no_security/gateway/mqtt_client.py 'localhost' 'test/gateway'

Open another Terminal: Make sure you have scanned and connected your peripheral using Bluetoothctl Issue mqtt command to get temperature according to characteristic handle for your device - the output shows in the other terminal:

mosquitto_pub -h localhost -t "test/gateway/in/read_characteristic" -m '{"bdaddr":"9A:61:DA:87:D2:C4", "handle":"/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service000a/char000b"}'

Result:

2024-03-10 12:37:53,163 - {"bdaddr": "9A:61:DA:87:D2:C4", "handle": "/org/bluez/hci0/dev_9A_61_DA_87_D2_C4/service000a/char000b", "cmd": "read_characteristic", "value": 2120, "result": 0}

Convert result: 2120 = 21.20 C