blepy

Blepy

A class-based wrapper for the peripheral functionalities provided by the library python-bluezero.

About

The primary goal of this library is to make it easier and more clearer about how to implement Bluetooth low energy Peripherals, including the associated Services, Characteristics and Descriptors. This is done by using a class-based wrapper for the BlueZ based python-bluezero library.

As seen in the figure below, a Service has one to many Characteristics and a Characteristic has (often) one to many Descriptors, which is what this library is built to follow.

Usage

Import blepy

To use blepy in your project, simply import the whole package:

import blepy

Service

Create unique BLE services by inheriting blepy.Service, including associated characteristics:

class ExampleService(blepy.Service):
   def __init__(self, primary):
      super().__init__(self, "UUID", primary)
      self.characteristics = [ExampleCharacteristic()]

Characteristic

Create unique BLE characteristics by inheriting blepy.Characteristic, including associated descriptors:

class ExampleCharacteristic(blepy.Characteristic):
   def __init__(self):
      super().__init__(self, "UUID")
      self.descriptors = [ExampleDescriptor()]     

Descriptor

Create unique BLE descriptors by inheriting blepy.Descriptor:

class ExampleDescriptor(blepy.Descriptor):
   def __init__(self):
      super().__init__(self, "UUID")

Peripheral

Create a new peripheral with included services by either using the blepy.Peripheral as it is:

# Initialize and publish the peripheral
peripheral = blepy.Peripheral([ExampleService(True)], adapter_address, local_name='Peripheral', appearance=0)
peripheral.publish()

... or by inherit from the blepy.Peripheral and create an unique peripheral:

class ExamplePeripheral(blepy.Peripheral):
    def __init__(self, adapter_address):
        services = [ExampleService(True)]
        super().__init__(services, adapter_address, local_name='Peripheral', appearance=0)

# Initialize and publish the peripheral
peripheral = ExamplePeripheral(adapter_address)
peripheral.publish()

Examples

(GATT Server) cpu-temperature.py

This example transmits (randomly generated) temperature values of the CPU over a single characteristic. Values are only updated when notification are switched on.

(UART) ble_uart.py

This example simulates a basic UART connection over two lines, TXD and RXD.

It is based on a proprietary UART service specification by Nordic Semiconductors. Data sent to and from this service can be viewed using the nRF UART apps from Nordic Semiconductors for Android and iOS.