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@ramunasd

ramunasd/cadence.py

Last active Jul 31, 2020
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ANT+ Garmin bike cadence and speed sensor reader
"""
Initialize a basic broadcast slave channel for listening to
an ANT+ HR monitor.
"""
import sys
import time
from ant.core import driver, node, event, message
from ant.core.constants import *
from config import *
def convertSB(raw):
value = int(raw[1]) << 8
value += int(raw[0])
return value
class CadenceListener(event.EventCallback):
lastEvent = None
def process(self, msg):
if isinstance(msg, message.ChannelBroadcastDataMessage):
page = msg.payload[1] & 0x7F
if page != 0:
return
eventTime = convertSB(msg.payload[5:7])
if eventTime == self.lastEvent:
return
self.lastEvent = eventTime
revolutions = convertSB(msg.payload[7:9])
print eventTime, ':', revolutions
NETKEY = '\xB9\xA5\x21\xFB\xBD\x72\xC3\x45'
# Initialize
stick = driver.USB1Driver(SERIAL, log=LOG, debug=DEBUG)
antnode = node.Node(stick)
antnode.start()
antnode.registerEventListener(CadenceListener())
# Set network key
network = node.Network(key=NETKEY, name='N:ANT+')
antnode.setNetworkKey(0, network)
# Get the first unused channel. Returns an instance of the node.Channel class.
channel = antnode.getFreeChannel()
# Initialize it as a receiving channel using our network key
channel.assign(network, CHANNEL_TYPE_TWOWAY_RECEIVE)
# Now set the channel id for pairing with an ANT+ HR monitor
channel.setID(122, 0, 0)
# Listen forever and ever (not really, but for a long time)
channel.searchTimeout = TIMEOUT_NEVER
# We want a ~4.06 Hz transmission period
channel.period = 8102
# And ANT frequency 57
channel.frequency = 57
try:
# Time to go live
channel.open()
print "Listening for events..."
while True:
time.sleep(60)
finally:
# Shutdown channel
channel.close()
channel.unassign()
# Shutdown
antnode.stop()
from ant.core import log
# USB1 ANT stick interface. Running `dmesg | tail -n 25` after plugging the
# stick on a USB port should tell you the exact interface.
SERIAL = '/dev/ttyUSB0'
# If set to True, the stick's driver will dump everything it reads/writes
# from/to the stick.
# Some demos depend on this setting being True, so unless you know what you
# are doing, leave it as is.
DEBUG = True
# Set to None to disable logging
LOG = None
#LOG = log.LogWriter()
# ========== DO NOT CHANGE ANYTHING BELOW THIS LINE ==========
#print "Using log file:", LOG.filename
#print ""
#!/usr/bin/python
import sys
import time
from ant.core import driver, node, event, message
from ant.core.constants import *
from config import *
NETKEY = '\xB9\xA5\x21\xFB\xBD\x72\xC3\x45'
CIRCUMFERENCE = 2.0
def convertSB(raw):
value = int(raw[1]) << 8
value += int(raw[0])
return value
class SpeedListener(event.EventCallback):
lastTime = None
lastRevolutions = None
def calcSpeed(self, time, revolutions):
if self.lastTime is None:
return None
if time < self.lastTime:
time += 64 * 1024
if revolutions < self.lastRevolutions:
revolutions += 65535
return (revolutions - self.lastRevolutions) * 1024.0 * CIRCUMFERENCE / (time - self.lastTime)
def process(self, msg):
if isinstance(msg, message.ChannelBroadcastDataMessage):
page = msg.payload[1] & 0x7F
if page != 0 and page != 5:
return
if page == 5:
stopped = (msg.payload[2] & 1 == 1)
if stopped:
print self.lastRevolutions, 0
eventTime = convertSB(msg.payload[5:7])
if eventTime == self.lastTime:
return
revolutions = convertSB(msg.payload[7:9])
speed = self.calcSpeed(eventTime, revolutions)
print revolutions, speed
self.lastTime = eventTime
self.lastRevolutions = revolutions
# Initialize
stick = driver.USB1Driver(SERIAL, log=LOG, debug=DEBUG)
antnode = node.Node(stick)
antnode.start()
antnode.registerEventListener(SpeedListener())
# Set network key
network = node.Network(key=NETKEY, name='N:ANT+')
antnode.setNetworkKey(0, network)
# Get the first unused channel. Returns an instance of the node.Channel class.
channel = antnode.getFreeChannel()
# Initialize it as a receiving channel using our network key
channel.assign(network, CHANNEL_TYPE_TWOWAY_RECEIVE)
# Now set the channel id for pairing with an ANT+ HR monitor
channel.setID(123, 0, 0)
# Listen forever and ever (not really, but for a long time)
channel.searchTimeout = TIMEOUT_NEVER
# We want a ~4.06 Hz transmission period
channel.period = 8118
# And ANT frequency 57
channel.frequency = 57
try:
# Time to go live
channel.open()
print "Listening for events..."
while True:
time.sleep(60)
finally:
# Shutdown channel
channel.close()
channel.unassign()
# Shutdown
antnode.stop()
@ryober

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@ryober ryober commented Nov 4, 2018

Hello. I wonder if speed.py should work for speed and cadence sensor with only corresponding setID and period?

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