I am making serial port communication device from a genious guy's work instructables.com.
It will measure the distance of the hamster's running in a day or month.
Using 4, 6 pin of the serial port cable, if the hamster runs, the device can count the numbers how many time did she run.
When I run the py file with Python27 like below, some errors occure. "python hamster-serial.py progress.txt"
I cannot understand what's going on. I am using windows8 and Python2.7 version.
Could you check my source, please?
import datetime
import serial
import sys
# Check for commandline argument. The first argument is the the name of the program.
if len(sys.argv) < 2:
print "Usage: python %s [Out File]" % sys.argv[0]
exit()
# Open the serial port we'll use the pins on and the file we'll write to.
ser = serial.Serial("/dev/ttyS1")
# Open the file we're going to write the results to.
f = open(sys.argv[1], 'a')
# Bring DTR to 1. This will be shorted to DSR when the switch is activated as the wheel turns.
ser.setDTR(1)
# The circumferance of the wheel.
circ = 0.000396 # miles
# Total distance traveled in this run of the program.
distance = 0.0
print "%s] Starting logging." % datetime.datetime.now()
start = datetime.datetime.now()
# This function a period of the wheel to a speed of the hamster.
def toSpeed(period):
global circ
seconds = period.days * 24 * 60 * 60 + period.seconds + period.microseconds / 1000000.
return circ / (seconds / 60. / 60.)
# Waits for the DSR pin on the serial port to turn off. This indicates that the
# switch has turned off and the magnet is no longer over the switch.
def waitForPinOff():
while ser.getDSR() == 1:
1 # Don't do anything while we wait.
# Waits for the DSR pin on the serial port to turn on. This indicates that the
# switch has turned on and the magnet is current over the switch.
def waitForPinOn():
while ser.getDSR() == 0:
1 # Don't do anything while we wait.
# The main loop of the program.
while 1:
waitForPinOn()
# Calculate the speed.
end = datetime.datetime.now()
period = end - start
start = end
speed = toSpeed(period)
# Increment the distance.
distance = distance + circ
waitForPinOff()
# We'll calculate the time the switch was held on too so but this isn't too useful.
hold = datetime.datetime.now() - start
# If the switch bounces or the hamster doesn't make a full revolution then
# it might seem like the hamster is running really fast. If the speed is
# more than 4 mph then ignore it, because the hamster can't run that fast.
if speed < 4.0:
# Print out our speed and distance for this session.
print "%s] Distance: %.4f miles Speed: %.2f mph" % (datetime.datetime.now(), distance, speed)
# Log it to and flush the file so it actually gets written.
f.write("%s\t%.2f\n" % (datetime.datetime.now().strftime("%D %T"), speed))
f.flush()
