204.174.159.1: Migrated reply #780

2020-02-22T07:17:14Z

Migrated reply #780

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sudo raspi-config # Enable Interfacing Options>I2C
sudo apt-get install i2c-tools # Install i2c-tools
nano ~/ups.py # Make a new python script

...
import struct
import smbus
import sys
import time
import os

lowest = 60

def readVoltage(bus):
"This function returns as float the voltage from the Raspi UPS Hat via the provided SMBus object"
address = 0x36
read = bus.read_word_data(address, 2)
swapped = struct.unpack("<H", struct.pack(">H", read))[0]
voltage = swapped * 78.125 /1000000
return voltage

def readCapacity(bus):
"This function returns as a float the remaining capacity of the battery connected to the Raspi UPS Hat via the provided SMBus object"
address = 0x36
read = bus.read_word_data(address, 4)
swapped = struct.unpack("<H", struct.pack(">H", read))[0]
capacity = swapped/256
return capacity

def shutdown():
os.system("sudo shutdown -h now")

bus = smbus.SMBus(1) # 0 = /dev/i2c-0 (port I2C0), 1 = /dev/i2c-1 (port I2C1)
print "Voltage:%5.2fV" % readVoltage(bus)
print "Battery:%5i%%" % readCapacity(bus)

# Only check if we are low
if readCapacity(bus) <= lowest:
first = readCapacity(bus)
time.sleep(5)
second = readCapacity(bus)
# If battery capacity is dropping
if first > second:
shutdown()
...

crontab -e
*/5 * * * * python /home/pi/ups.py > /dev/null 2>&1 #Add to crontab. Run script every 5 min.

CommentStreams:764d7138a34fa5fbf3293982d7ad839b - Revision history

204.174.159.1: Migrated reply #780