Custom Services example using Python library

Introduction

The Python library comes with a range of convenient AT commands that can be used to control various aspects of the BleuIO dongle, including scanning, advertising, connecting, and, most importantly, setting up custom services. Custom BLE services can be configured with just a few lines of Python code, to meet the specific requirements of the application.

This script will work on BleuIO Python library 1.2.0 or above

Creating a Custom Service with BleuIO’s Python Library

An example Python script that showcases how to create a custom BLE service using BleuIO’s Python library:

# (C) 2023 Smart Sensor Devices AB

import time
from datetime import datetime

from bleuio_lib.bleuio_funcs import BleuIO

# This example will show how to setup your own service
# Press Ctrl-C to exit the script.


# Scan result Callback function
def my_scan_callback(scan_input):
    print("\n\nmy_scan_callback: " + str(scan_input))


# Event Callback function
def my_evt_callback(scan_input):
    print("\n\nmy_evt_callback: " + str(scan_input))


# Start BleuIO
my_dongle = BleuIO()
# Register callback functions for scan results and events
my_dongle.register_evt_cb(my_evt_callback)
my_dongle.register_scan_cb(my_scan_callback)

# Run ATI Command
resp = my_dongle.ati()
print(resp.Cmd)
print(resp.Ack["errMsg"])
print(resp.Rsp)

print("My Role: " + my_dongle.status.role)
print("Is Adv: " + str(my_dongle.status.isAdvertising))
print("Is Connected: " + str(my_dongle.status.isConnected))

# Set role to dual if it isn't set already
if not my_dongle.status.role == my_dongle.gaproles.DUAL:
    resp = my_dongle.at_dual()
    print(resp.Cmd)
    print(resp.Ack)

# Disconnect if we're connected
if my_dongle.status.isConnected:
    resp = my_dongle.at_gapdisconnectall()
    print(resp.Cmd)
    print(resp.Ack)

# Stop Advertising if we're advertising
if my_dongle.status.isAdvertising:
    resp = my_dongle.at_advstop()
    print(resp.Cmd)
    print(resp.Ack)

# Stop custom service just in case it had been started previously
resp = my_dongle.at_customservice_stop()
print(resp.Cmd)
print(resp.Ack)

# Service

# Set service UUID
resp = my_dongle.at_customservice(
    0, my_dongle.UUID, "ee6ec068-7447-4045-9fd0-593f3ba3c2ee"
)
print(resp.Cmd)
print(resp.Ack)

# Characteristic 1

# Set characteristic 1 UUID
resp = my_dongle.at_customservice(
    2, my_dongle.UUID, "018f55d9-d747-4c4e-a87b-e9b074ffd2b6"
)
print(resp.Cmd)
print(resp.Ack)

# Set characteristic 1 value length
resp = my_dongle.at_customservice(1, my_dongle.CHAR_LENGTH, "100")
print(resp.Cmd)
print(resp.Ack)

# Set characteristic 1 value
# Here we set it to the current time in hours, minutes and seconds format.
cbTime = datetime.now()
char1_data = cbTime.strftime("%H:%M:%S")
resp = my_dongle.at_customservice(1, my_dongle.CHAR_VALUE, char1_data)
print(resp.Cmd)
print(resp.Ack)

# Set characteristic 1 permissions
resp = my_dongle.at_customservice(1, my_dongle.CHAR_PERMISSION, "R")
print(resp.Cmd)
print(resp.Ack)

# Set characteristic 1 properties
# We set it to Read and Notify
resp = my_dongle.at_customservice(1, my_dongle.CHAR_PROPERTY, "NR")
print(resp.Cmd)
print(resp.Ack)

# Characteristic 2

# Set characteristic 2 UUID
resp = my_dongle.at_customservice(
    2, my_dongle.UUID, "a693ba2c-f0df-40cb-aea7-8ae47281d997"
)
print(resp.Cmd)
print(resp.Ack)

# Set characteristic 2 value length
resp = my_dongle.at_customservice(2, my_dongle.CHAR_LENGTH, "100")
print(resp.Cmd)
print(resp.Ack)

# Set characteristic 2 value
# Here we set it to the current time in month, days and years format.
cbTime = datetime.now()
char2_data = cbTime.strftime("%m/%d/%Y")
resp = my_dongle.at_customservice(2, my_dongle.CHAR_VALUE, char2_data)
print(resp.Cmd)
print(resp.Ack)

# Set characteristic 2 permissions
resp = my_dongle.at_customservice(2, my_dongle.CHAR_PERMISSION, "R")
print(resp.Cmd)
print(resp.Ack)

# Set characteristic 2 properties
# We set it to Read and Indicate
resp = my_dongle.at_customservice(2, my_dongle.CHAR_PROPERTY, "IR")
print(resp.Cmd)
print(resp.Ack)

# Here we check that the service data we set has gone in
resp = my_dongle.at_customservice()
print(resp.Cmd)
print(resp.Ack)
print(resp.Rsp)
print(resp.End)

# Here we start the custom service so next time we advertise and someone connects they will see the new service
resp = my_dongle.at_customservice_start()
print(resp.Ack)

# Here we start advertising so other devices can detect us and connect
resp = my_dongle.at_advstart()
print(resp.Ack)

# Going in a never ending loop that will just update the values of Characteristic 1 and 2 every second.
# If anyone is subscribed we will notify/indicate them.
while True:
    cbTime = datetime.now()
    notiCharTime = cbTime.strftime("%H:%M:%S")
    resp = my_dongle.at_customservice(1, my_dongle.CHAR_VALUE, notiCharTime)
    print(resp.Cmd)
    print(resp.Ack)

    indiCharTime = cbTime.strftime("%m/%d/%Y")
    resp = my_dongle.at_customservice(2, my_dongle.CHAR_VALUE, indiCharTime)
    print(resp.Cmd)
    print(resp.Ack)
    time.sleep(1)

The example script demonstrates the process of setting up a custom service with two characteristics. Characteristic 1 holds the current time in hours, minutes, and seconds format, while Characteristic 2 contains the date in month, day, and year format. The script registers callbacks for scan results and events, sets up the service UUID, characteristic UUIDs, permissions, properties, and starts advertising the custom service.

---