beacon_on_MAC.py

#!/usr/bin/env python2.7

""" Beacon Class """

""" Thomas Verbeke - thomas.verbeke@vub.ac.be

        Based on LoRaMAC

        Send a LoRaMAC frame and open a window for receiving the ACK.
        Retry after x seconds
    
    Tested with Embed LoRa Module (SX1276 Semtech chip)
   
"""

import time
from math import ceil, floor
from time import sleep
from SX127x.LoRa import *
from LoRaMAC import LoRaMAC

BOARD.setup()
	
""" 	868 ISM BANDS   
	
	BAND 	/	DutyCycle 	/ 		MaxPower		/  	Channel Configuration Options		/  	LoRaWAN use
	============================================================================
	h1.2		/	1%			/		14 dBm		/ 	15 x 125 or 10x 250 or 4x500			/	5X125 kHz
	h1.4		/	1%			/		14 dBm		/	3x 125 or 1x250 or 1x 500**			/	3X125 or 2x125 and 1x250 kHz
	h1.5		/	0.1%		/		14 dBm		/	2x 125 or 1x250					/	1XFSK
	h1.6		/	10%			/		27 dBm		/	1x 125							/	Reception Window channel				
	h1.7		/	100%		/		7 dBm		/	1x 125							/	not used

	Band h1.6 is used as the BEACON channel or reception channel
	Band h1.7 is used as last resort channel when device has used up all of its available duty cycle resources
	** Modify Tx filter settings needed: done by writing "0xE1" in register 0x3D

"""

BAND0_868 = {'name': "RF_Band_868_h1.2" , 'dutyCycle' : 100, 'maxPower' : 14, 'maxTxTime' : 36000 } # 1% use, maxTxTime in ms
BAND1_868 = {'name': "RF_Band_868_h1.4"  , 'dutyCycle' : 100, 'maxPower' : 14, 'maxTxTime' : 36000} # 1% use
BAND2_868 = {'name': "RF_Band_868_h1.5"  , 'dutyCycle' : 10000, 'maxPower' : 14, 'maxTxTime' : 3600} # 0.1% use
BAND3_868 = {'name': "RF_Band_868_h1.6"  , 'dutyCycle' : 10, 'maxPower' : 14, 'maxTxTime' : 360000}  #mbed platform only connect high efficiency amp so TX power is limited at 14 dBm # 10% use
BAND4_868 = {'name': "RF_Band_868_h1.7"  , 'dutyCycle' : 1, 'maxPower' : 7, 'maxTxTime' : 3600000} #100% use

bands_868 = {'BAND0' : BAND0_868, 'BAND1' : BAND1_868, 'BAND2' : BAND2_868, 'BAND3' : BAND3_868, 'BAND4' : BAND4_868}

#default channels in bands h1.6 and h1.7
channel_D1_868= {'name' : 'CH_D1_868_Def_BEACON' , 'freq' : 869.525,  'bw' : BW.BW_125, 'band' : BAND3_868} #Freq is center freq
channel_D2_868= {'name' : 'CH_D2_868_Def_ALWAYS_ON' , 'freq' : 869.850 ,  'bw' : BW.BW_125, 'band' : BAND4_868} #Freq is center freq
"""
#Channel configurations
OPTION 1:  	High capacity : conf h1.2 to use 15x125 kHz and use h1.4 and h1.5 as the high speed channel
OPTION 2:	 	High speed:  4x500 kHz channels in the h1.2 band and 3x125 kHz channels in h1.4 and 1x250 kHz channel in h1.5 
OPTION 3: 	LoRaWAN avoidance mode: avoid h1.4 band and use h1.2 band from 865.1-566.9 (10x 125 kHz channels)
OPTION 4: 	Testing: 1x 125 kHz channel, 1x250 kHz channel and 1x500 kHz channel in both h1.2 and 
"""	
channel1_868 = {'name' : 'CH1_868_125' , 'freq' : 865.100 ,  'bw' : BW.BW_125,  'band' : BAND0_868}
channel2_868 = {'name' : 'CH2_868_125' , 'freq' : 865.200 ,  'bw' : BW.BW_250,  'band' : BAND0_868}
channel3_868 = {'name' : 'CH3_868_125' , 'freq' : 865.600 ,  'bw' : BW.BW_500,  'band' : BAND0_868} 

channel4_868 = {'name' : 'CH4_868_125' , 'freq' : 868.050 ,  'bw' : BW.BW_125,  'band' : BAND1_868}
channel5_868 = {'name' : 'CH5_868_125' , 'freq' : 868.300 ,  'bw' : BW.BW_250,  'band' : BAND1_868}
channel6_868 = {'name' : 'CH6_868_125' , 'freq' : 868.300 ,  'bw' : BW.BW_500,  'band' : BAND1_868} #warning: to use this channel register "0xE1" must be written in register 0x3D

class Beacon(LoRaMAC):
	def __init__(self, verbose=True):
                super(Beacon, self).__init__(verbose)
                
		""" General Settings for the SX127X """

		""" Header ON/OFF (Implicit Mode) - Turning header off is called implicit mode 
						    Payload length, coding rate, payload CRC must 
						    be fixed at tx and rx side.
						    
		    Options: [False: OFF, True:ON]
		"""
		#headerOff=False
		self.transmission['headerOff'] = False

		""" Bandwith 
		    Options: [125 kHz | 250 kHz | 500 kHz]
		"""
		#bw=BW.BW_125
		#self.transmission['bw'] = BW.BW_125
		#no longer selection of bw but of communication channel
		self.transmission['channel'] = channel_D2_868
		

		""" Spreading factor / Data Rate
		    Options: [6:64 | 7:128 | 8:256 | 9:512 | 10:1024 | 11:2048 | 12:4096 chips]
		"""
		#sf=7 
		self.transmission['sf']=7 

		""" Code Rate
		    Options: [1:4/5, 2:4/6, 3:4/7, 4:4/8]
		"""
		#cr=CODING_RATE.CR4_5
		self.transmission['cr']=CODING_RATE.CR4_5 

		""" Payload CRC ON/OFF
		    Options: [False: OFF, True:ON]
		    In implicit mode RxPayloadCrcOn should be set on both Tx and Rx
		"""
		#rx_crc_on=True
		self.transmission['rx_crc_on']=True

		""" Preamble length 
		    Options: 6-65535 (Hardware adds 4 more symbols)
		"""
		#preambleLen=8
		self.transmission['preambleLen']=8

		""" Low Data Rate Optimization (Improves robustness of transmission; necessary at high spreading factors or if symbol duration higher than 16ms
		    Options: [True/False]
		"""
		#low_data_rate_optim=False
		self.transmission['low_data_rate_optim']=False


		#Update transceiver configuration
		self.updateConfiguration()

		#set_hop_channel (not available in HAL yet)
		#set_hop_period

		# DIO MAPPING
		#               0x00 for 	RxDone (on DIO0)		| 0x40 for 	        TxDone (on DIO0)
		#	 		        CadDone (on DIO3)		| 			CadDone (on DIO3)  
		#               0x01 for 	RxDone (on DIO0)		| 0x42 for		TxDone  (on DIO0)
		# 			        ValidHeader (on DIO3)	        |			ValidHeader (on DIO3)
		
		mapping = 0x01 
		self.spi.xfer([REG.LORA.DIO_MAPPING_1 | 0x80, mapping])[1]
		self.get_dio_mapping() # update DIO mapping

	def on_rx_done(self):
		#prob good idea to use full buffer (for later)
		#TODO check for bad crc
		#we can also use a timeout functionality to stop listening after predetermined amount of time in order to save energy
		#using RxTimeOut interrupt TimeOut = LoRaRxTimeout * Ts
	    
		print("\n(RxDone) Packet Received")
		
		#print('num bytes payload', self.get_rx_nb_bytes())
	    
		payload = self.read_payload_noheader()
		#print('Payload:', payload,map(hex, payload)) 
		print('*** Payload: %s' % payload) 
	    
		decoded_msg_str = ''.join(map(chr,payload)) # convert byte to string and join
		print ('*** Decoded: %s' %decoded_msg_str)

                if self.incoming['type'] == "ADMIN":
                        self.processADMIN_frame(payload)
                elif self.incoming['type'] == "ACK":
                        self.processACK(payload)
                        
		#self.reset_ptr_rx() 

	def on_tx_done(self): 
		print("\n(TxDone) Packet send")
		self.set_irq_flags(tx_done=1)		#clear interrupt flag
		#self.state['wf_ack']= True		#set ACK state
		print "state %s" % self.state['wf_ack']
		self.timer = time.clock()			#set timer
		self.openReceiveWindow(100) #open receive window for ACK reception HOW LONG??
		
		
	""" Interrupt Utility Functions """
	def on_rx_timeout(self):
		print("\n(RxTimeOut) Rx Timeout (No ACK detected in timeframe)")
		self.set_irq_flags(rx_timeout=1)		#clear interrupt flag
		#self.state['wf_ack']= False			#clear ACK state
		self.set_mode(MODE.STDBY)
		
                print("number of retries:%s" % self.retries)
                
                if (self.retries < self.options['numRetries']):
                        self.retries += 1
                        self.writeFrame(self.lastFrame)
                        sleep(2)
                else:
                        self.state['wf_ack']= False			#clear ACK state
                        self.retries = 0 
                
	def start(self):
		
		print "Assemble frame and (re)send every 5 seconds"
		#frame = self.prepareFrame("BEACON",[0x50, 0x69, 0x6E, 0x67] )
                #print self.channelList.index(channel_D1_868)
                #print self.channelList.index(channel_D2_868)
                #print self.channelList.index(channel1_868)

                print channel1_868['name']
		while True:
                        frame = self.send_MAC_AdminFrame(channel=channel1_868, sf=SF.SF_8, linkCheck=True)
                        while(self.state['wf_ack']!= False):
                              sleep(1)
			sleep(8)

beacon = Beacon(verbose=False)
print(beacon)
assert(beacon.get_agc_auto_on() == 1)

try: input("Press enter to start...")
except: pass

try:
    beacon.start()
except KeyboardInterrupt:
    sys.stdout.flush()
    print("")
    sys.stderr.write("KeyboardInterrupt\n")
finally:
    sys.stdout.flush()
    beacon.set_mode(MODE.SLEEP)
    print(beacon)
    BOARD.teardown()