watercounter/water-counter
watercounter/water-counter
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Code Issues Releases Wiki Activity

Use interrupt with edge triggering (epoll)

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This commit is contained in:
Martin Kompf 2016-03-28 17:54:40 +02:00
parent a67be3af05
commit 6a362159f7
2 changed files with 25 additions and 17 deletions
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2
setup.sh
View File

@ -1 +1,3 @@
gpio unexport 9
gpio export 9 in gpio export 9 in
gpio edge 9 rising

40
wairc.py
View File

@ -22,16 +22,16 @@
# You should have received a copy of the GNU General Public License # You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>. # along with this program. If not, see <http://www.gnu.org/licenses/>.
import serial
import time import time
import sys import sys
import os import os
import re import re
import select
import argparse import argparse
import rrdtool import rrdtool
# GPIO value files (wiringPi) # GPIO pin to read from
gpin = '/sys/class/gpio/gpio9/value' gpio_pin = 9
# counter unit: 1 revolution = x m^3 # counter unit: 1 revolution = x m^3
trigger_step = 0.001 trigger_step = 0.001
@ -78,6 +78,12 @@ def last_rrd_count():
handle.close() handle.close()
return val return val
# Setup gpio edge interrupt triggering
def setup_gpio(pin):
os.system("gpio export {} in".format(pin))
os.system("gpio edge {} rising".format(pin))
# Main # Main
def main(): def main():
# Check command args # Check command args
@ -88,29 +94,29 @@ def main():
if args.create: if args.create:
create_rrd() create_rrd()
trigger_state = 0
counter = last_rrd_count() counter = last_rrd_count()
print "restoring counter to %f" % counter print "restoring counter to %f" % counter
while(1==1): # open gpio input value file
# read gpio input value file # and register handler for edge trigger
f = open(gpin, 'r') setup_gpio(gpio_pin)
line = f.read().strip() f = open("/sys/class/gpio/gpio{}/value".format(gpio_pin), 'r')
f.close() epoll = select.epoll()
epoll.register(f, select.EPOLLIN | select.EPOLLET)
events = epoll.poll() # eat the first edge
old_state = trigger_state while(1==1):
if line == '1': events = epoll.poll()
trigger_state = 1 f.seek(0)
elif line == '0': value = f.read(1)
trigger_state = 0 if value == '1':
if old_state == 1 and trigger_state == 0: # trigger edge detected -> update count rrd
# trigger active -> update count rrd
counter += trigger_step counter += trigger_step
update = "N:%.3f:%.3f" % (counter, trigger_step) update = "N:%.3f:%.3f" % (counter, trigger_step)
#print update #print update
rrdtool.update(count_rrd, update) rrdtool.update(count_rrd, update)
time.sleep(0.1)
f.close()
if __name__ == '__main__': if __name__ == '__main__':
main() main()