read-weight.py

# read weight value
# funktioniert derzeit nicht mit python3
import RPi.GPIO as GPIO
import time
import sys
from hx711 import HX711

def cleanAndExit():
	print("Cleaning...")
	GPIO.cleanup()
	print("Bye!")
	sys.exit()

hx = HX711(5, 6)
hx.set_reading_format("LSB", "MSB")

# HOW TO CALCULATE THE REFFERENCE UNIT
# To set the reference unit to 1. Put 1kg on your sensor or anything you have and know exactly how much it weights.
# In this case, 92 is 1 gram because, with 1 as a reference unit I got numbers near 0 without any weight
# and I got numbers around 184000 when I added 2kg. So, according to the rule of thirds:
# If 2000 grams is 184000 then 1000 grams is 184000 / 2000 = 92.
#hx.set_reference_unit(113)
hx.set_reference_unit(92)

hx.reset()
hx.tare()

while True:
	try:
		val = hx.get_weight(5)
		print(val)

		hx.power_down()
		hx.power_up()
		time.sleep(0.5)
	except (KeyboardInterrupt, SystemExit):
		cleanAndExit()