#-------------------------------------------------------------------------------

# Version info

#-------------------------------------------------------------------------------

__version__ = "2020-12-27"

# 2020-12-27 Rollover more according specification

# 2020-06-16 Modified: device-by-zero due to zero Cadence/SpeedKmh

# 2020-06-09 First version, based upon antHRM.py

#-------------------------------------------------------------------------------

import time

import antDongle as ant

import logfile

def Initialize():

global PedalEchoPreviousCount, CadenceEventTime, CadenceEventCount, SpeedEventTime, SpeedEventCount

PedalEchoPreviousCount = 0 # There is no previous

CadenceEventTime = 0 # Initiate the even variables

CadenceEventCount = 0

SpeedEventTime = 0

SpeedEventCount = 0

def BroadcastMessage (_PedalEchoTime, PedalEchoCount, SpeedKmh, Cadence):

global PedalEchoPreviousCount, CadenceEventTime, CadenceEventCount, SpeedEventTime, SpeedEventCount

#-------------------------------------------------------------------------

# If pedal passed the magnet, calculate new values

# Otherwise repeat previous message

# Avoid devide-by-zero!

#-------------------------------------------------------------------------

if PedalEchoCount != PedalEchoPreviousCount and Cadence > 0 and SpeedKmh > 0:

#---------------------------------------------------------------------

# Cadence variables

# Based upon the number of pedal-cycles that are done and the given

# cadence, calculate the elapsed time.

# _PedalEchoTime is not used, because that give rounding errors and

# an instable reading.

#---------------------------------------------------------------------

PedalCycles = PedalEchoCount - PedalEchoPreviousCount

ElapsedTime = PedalCycles / Cadence * 60 # count / count/min * seconds/min = seconds

CadenceEventTime += ElapsedTime * 1024 # 1/1024 seconds

CadenceEventCount += PedalCycles

#---------------------------------------------------------------------

# Speed variables

# First calculate how many wheel-cycles can be done

# Then (based upon rounded #of cycles) calculate the elapsed time

#---------------------------------------------------------------------

Circumference = 2.096 # Note: SimulANT has 2.070 as default

WheelCadence = SpeedKmh / 3.6 / Circumference # km/hr / kseconds/hr / meters = cycles/s

WheelCycles = round(ElapsedTime * WheelCadence, 0) # seconds * /s = cycles

ElapsedTime = WheelCycles / SpeedKmh * 3.6 * Circumference

SpeedEventTime += ElapsedTime * 1024

SpeedEventCount += WheelCycles

#-------------------------------------------------------------------------

# Rollover after 0xffff

#-------------------------------------------------------------------------

CadenceEventTime = int(CadenceEventTime) & 0xffff # roll-over at 65535 = 64 seconds

CadenceEventCount = int(CadenceEventCount) & 0xffff # roll-over at 65535

SpeedEventTime = int(SpeedEventTime) & 0xffff # roll-over at 65535 = 64 seconds

SpeedEventCount = int(SpeedEventCount) & 0xffff # roll-over at 65535

#-------------------------------------------------------------------------

# Prepare for next event

#-------------------------------------------------------------------------

PedalEchoPreviousCount = PedalEchoCount

#-------------------------------------------------------------------------

# Compose message

#-------------------------------------------------------------------------

info = ant.msgPage_SCS (ant.channel_SCS, CadenceEventTime, CadenceEventCount, SpeedEventTime, SpeedEventCount)

scsdata = ant.ComposeMessage (ant.msgID_BroadcastData, info)

#-------------------------------------------------------------------------

# Return message to be sent

#-------------------------------------------------------------------------

return scsdata

#-------------------------------------------------------------------------------

# Main program for module test

#-------------------------------------------------------------------------------

if __name__ == "__main__":

Initialize()

time.sleep(1)

scsdata = BroadcastMessage (0, 1, 45.6, 123)

print (logfile.HexSpace(scsdata))