I got the battery shutdown script working!
I didn't even need to use a GPIO it's all scripted to take the measurements from the fuel gauge board over the I2C bus. I've even got it all running in just one script now.
Because I can take accurate battery measurements now I can script actions at any voltage and I can trigger different led flashes for low battery and critical battery as well as the shutdown.
That's next.
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(along with play and pause toggle on the main button now that Bob made media keys work)
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pi@raspberrypi ~ $ sudo ./gpio.py
Battery OK: 3.8119 volts
Battery OK: 3.8119 volts
Battery OK: 3.8119 volts
Battery Lo: 3.7045 volts - Checking for 20 seconds: 0
Battery Lo: 3.7045 volts - Checking for 20 seconds: 1
Battery Lo: 3.7045 volts - Checking for 20 seconds: 2
Battery Lo: 3.7032 volts - Checking for 20 seconds: 3
Battery Lo: 3.7032 volts - Checking for 20 seconds: 4
Battery Lo: 3.6996 volts - Checking for 20 seconds: 5
Battery Lo: 3.702 volts - Checking for 20 seconds: 6
Battery Lo: 3.702 volts - Checking for 20 seconds: 7
Battery Lo: 3.702 volts - Checking for 20 seconds: 8
Battery Lo: 3.702 volts - Checking for 20 seconds: 9
Battery Lo: 3.702 volts - Checking for 20 seconds: 10
Battery Lo: 3.702 volts - Checking for 20 seconds: 11
Battery Lo: 3.702 volts - Checking for 20 seconds: 12
Battery Lo: 3.7008 volts - Checking for 20 seconds: 13
Battery Lo: 3.7008 volts - Checking for 20 seconds: 14
Battery Lo: 3.7008 volts - Checking for 20 seconds: 15
Battery Lo: 3.6996 volts - Checking for 20 seconds: 16
Battery Lo: 3.6996 volts - Checking for 20 seconds: 17
Battery Lo: 3.6996 volts - Checking for 20 seconds: 18
Battery Lo: 3.6996 volts - Checking for 20 seconds: 19
Battery Lo: 3.6996 volts - Checking for 20 seconds: 20
Battery Low For More Than 20 Seconds Shutting Down:
Broadcast message from root@raspberrypi (Tue May 5 20:45:17 2015):
System halted by Low Battery Alert
The system is going down for system halt NOW!
Battery Lo: 3.6996 volts - Checking for 20 seconds: 21
Battery Low For More Than 20 Seconds Shutting Down:
Broadcast message from root@raspberrypi (Tue May 5 20:45:18 2015):
System halted by Low Battery Alert
The system is going down for system halt NOW!
Battery Lo: 3.6605 volts - Checking for 20 seconds: 22
Battery Low For More Than 20 Seconds Shutting Down:
Broadcast message from root@raspberrypi (Tue May 5 20:45:19 2015):
System halted by Low Battery Alert
The system is going down for system halt NOW!
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Here's the cleaned up script with the battery monitor set for 3.2v - my scripting is getting a little tidier.
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#!/usr/bin/env python2.7
from time import sleep
import os
import subprocess
import RPi.GPIO as GPIO
import fuel
BUTTON1 = 17 # GPIO channel 17 - RestartMC/Shutdown/Reboot
LED1 = 26 # GPIO channel 26 - Power LED
#BATTERY1 = 23 # GPIO channel 23 - Low Battery
POWEROFF1 = 22 # GPIO channel 22 - Power off kill switch
GPIO.setmode(GPIO.BCM)
GPIO.setup(BUTTON1, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(LED1, GPIO.OUT, pull_up_down=GPIO.PUD_UP)
GPIO.output(LED1, 1)
GPIO.setup(BATTERY1, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
GPIO.setup(POWEROFF1, GPIO.OUT, pull_up_down=GPIO.PUD_DOWN)
fuel.writeAlertThreshold(5)
def button_action(BUTTON1):
print('Button press = negative edge detected on Button %s'%BUTTON1)
button_press_timer = 0
while True:
if (GPIO.input(BUTTON1) == False) : # while button is still pressed down
button_press_timer += 1 # keep counting until button is released
else: # button is released, figure out for how long
if (button_press_timer > 7) : # pressed for > 7 seconds
print "long press > 7 : ", button_press_timer
# do what you need to do before halting
subprocess.call(['sudo reboot &'], shell=True)
elif (button_press_timer > 3 < 7) : # pressed for > 3 < 7 seconds
print "medium press > 3 < 7 : ", button_press_timer
# do what you need to do before rebooting
subprocess.call(['./RestartMC20.sh & echo "Killing MC20" &'], shell=True)
elif (button_press_timer > 1 < 3) : # press for > 1 < 3 seconds
print "short press > 1 < 3 : ", button_press_timer
# do what you need to do before restarting mediacenter20
subprocess.call(['shutdown -h now "System halted by GPIO action" &'], shell=True)
button_press_timer = 0
sleep(1)
def battery_monitor():
batt_timer = 0
while True:
if (fuel.readVCell()) >= 3.2: #check battery voltage
#print("Battery OK: {0} volts".format(fuel.readVCell()))
batt_timer = 0
else: # batt is low
print "Battery Low: {0} volts".format(fuel.readVCell()), "- Checking for 20 seconds: {0}".format(batt_timer)
batt_timer += 1 # keep counting
if (batt_timer > 20) : # batt low for > 20 seconds
print "Battery Low For More Than 20 Seconds - Shutting Down: "
subprocess.call(['shutdown -h now "System halted by Low Battery Alert" &'], shell=True)
sleep(1)
GPIO.add_event_detect(BUTTON1, GPIO.FALLING, callback=button_action, bouncetime=200)
#GPIO.add_event_detect(BATTERY1, GPIO.FALLING, callback=battery_monitor, bouncetime=200)
try:
while True:
sleep(5)# sleep and do the battery monitor loop
battery_monitor()
except KeyboardInterrupt:
GPIO.cleanup() # clean up GPIO on CTRL+C exit
GPIO.cleanup() # clean up GPIO on normal exit