cr02_lorawan.py

"""
.. module:: cr02_lorawan

********************
CR02_LoRaWAN Module
********************

This is a module for the XinaBox LoRaWAN implementation using `CR02 <https://wiki.xinabox.cc/CR02_-_LoRa_with_ATmega328P_Core>`_ as an I2C slave device with `CW02 <https://docs.zerynth.com/latest/official/board.zerynth.xinabox_esp32/docs/index.html?highlight=cw02>`_ as its master. CR02 operates in the 868MHz range.

==============================
Using CR02_LoRaWAN Module
==============================

CR02_LoRaWAN module is dependant on a *.hex* file which must be uploaded to CR02 via IP01 before the module can be utilized. The file can be found `here <https://github.com/xinabox/arduino-LMIC/releases/tag/0.5.0>`_ accompanied with instructions on flashing it to CR02.

Once flashed, CR02 can be used as a node to connect to The Things Network.


    """
import i2c

class CR02_TTN(i2c.I2C):
    """
==================
CR02_TTN class
==================

.. class:: CR02_TTN(drvname=I2C0, addr=8, clk=100000)

    Creates an intance of the CR02_TTN class.

    :param drvname: I2C Bus used '( I2C0, ... )'
    :param addr: Slave address, default 8
    :param clk: Clock speed, default 100kHz
    """
    def __init__(self, drvname=I2C0, addr=8 , clk=100000):
        i2c.I2C.__init__(self, drvname, addr, clk)
        self._addr = addr
        try:
            self.start()
        except PeripheralError as e:
            print(e)
            raise e
        
    def init(self, appeui, deveui, appkey, debug=False):
        '''
.. method:: init()
        
        Sends the keys generated by The Things Network (TTN) application to CR02. CR02 then establishes a connection with TTN.
        Raises an exeption if any error occurs during initialization.

        :param appeui: The appeui generated by TTN application
        :param deveui: The deveui generated by TTN application
        :param appkey: The appkey generated by TTN application
        :param debug: Set True to view debugging information on CR02. Can only be used with MD03 whereby the serial communication between CW02 and CR02 is seperated.

        '''
        keys=[appeui,deveui,appkey]
        try:
            if debug == False:
                self.write('0')
            elif debug == True:
                self.write('1')
            ack = 0
            for keyx, key in enumerate(keys, 0x61):
                self.write_bytes(keyx)
                sleep(50)
                self.write(key)
                sleep(100)
                ack = self.read(1)
            if ack == str(1):
                print('keys received')
            else:
                print('keys not received')
        except Exception as e:
            print(e)
            raise e
    
    def sendString(self, dataToSend=""):
        '''
.. method:: sendString(dataToSend="")

        Sends a string of limit 30 bytes over the I2C bus to CR02. CR02 in turn sends the string to TTN.
        Exception raised if unsuccessful.

        :param dataToSend: string to be sent to TTN.

        '''
        try:
            newData = '0' + dataToSend
            self.write(newData)
        except Exception as e:
            print(e)
            raise e
        
    def sendNumber(self, numberToSend=0):
        '''
.. method:: sendNumber(numberToSend=0)

        Sends a number of limit 30 bytes over the I2C bus to CR02. CR02 in turn sends the number to TTN.
        Exception raised if unsuccessful.

        :param sendNumber: number to be sent to TTN.
        
        '''
        try:
            newData = '0' + str(numberToSend)
            self.write(newData)
        except Exception as e:
            print(e)
            raise e