Adafruit_Learning_System_Gu.../NAU7802_Food_Scale/code.py
BlitzCityDIY 7cf6458cf3 Updating code and calibration
Fixing all misspellings of calibration. Also tweaks to code after running long-term with larger weight.
2022-07-13 09:52:47 -04:00

365 lines
12 KiB
Python

# SPDX-FileCopyrightText: 2022 Liz Clark for Adafruit Industries
# SPDX-License-Identifier: MIT
import time
import board
from digitalio import DigitalInOut, Direction, Pull
from adafruit_ht16k33.segments import Seg14x4
from cedargrove_nau7802 import NAU7802
from calibration import calibration
# I2C setup with STEMMA port
i2c = board.STEMMA_I2C()
# alphanumeric segment displpay setup
# using two displays together
display = Seg14x4(i2c, address=(0x70, 0x71))
# start-up text
display.print("*HELLO* ")
# button LEDs
blue = DigitalInOut(board.A1)
blue.direction = Direction.OUTPUT
green = DigitalInOut(board.A3)
green.direction = Direction.OUTPUT
# buttons setup
blue_btn = DigitalInOut(board.A0)
blue_btn.direction = Direction.INPUT
blue_btn.pull = Pull.UP
green_btn = DigitalInOut(board.A2)
green_btn.direction = Direction.INPUT
green_btn.pull = Pull.UP
# nau7802 setup
nau7802 = NAU7802(board.STEMMA_I2C(), address=0x2A, active_channels=2)
nau7802.gain = 128
enabled = nau7802.enable(True)
# zeroing function
def zero_channel():
"""Initiate internal calibration for current channel; return raw zero
offset value. Use when scale is started, a new channel is green_btned, or to
adjust for measurement drift. Remove weight and tare from load cell before
executing."""
blue.value = True
print(
"channel %1d calibrate.INTERNAL: %5s"
% (nau7802.channel, nau7802.calibrate("INTERNAL"))
)
blue.value = False
print(
"channel %1d calibrate.OFFSET: %5s"
% (nau7802.channel, nau7802.calibrate("OFFSET"))
)
blue.value = True
zero_offset = read_raw_value(100) # Read 100 samples to establish zero offset
print("...channel %1d zeroed" % nau7802.channel)
blue.value = False
return zero_offset
# read raw value function
def read_raw_value(samples=100):
"""Read and average consecutive raw sample values. Return average raw value."""
sample_sum = 0
sample_count = samples
while sample_count > 0:
if nau7802.available:
sample_sum = sample_sum + nau7802.read()
sample_count -= 1
return int(sample_sum / samples)
# function for finding the average of an array
def find_average(num):
count = 0
for n in num:
count = count + n
average = count / len(num)
return average
# calibration function
def calculateCalibration(array):
for _ in range(10):
blue.value = True
green.value = False
nau7802.channel = 1
#value = read_raw_value()
print("channel %1.0f raw value: %7.0f" % (nau7802.channel, abs(read_raw_value())))
array.append(abs(read_raw_value()))
blue.value = False
green.value = True
time.sleep(1)
green.value = False
avg = find_average(array)
return avg
# blink LED function
def blink(led, amount, count):
for _ in range(count):
led.value = True
time.sleep(amount)
led.value = False
time.sleep(amount)
# zeroing on startup
display.fill(0)
display.marquee("CLEAR SCALE CLEAR", 0.3, False)
time.sleep(2)
display.fill(0)
display.print("ZEROING")
time.sleep(3)
# zeroing each channel
nau7802.channel = 1
zero_channel() # Calibrate and zero channel
display.fill(0)
display.print("STARTING")
# variables and states
clock = time.monotonic() # time.monotonic() device
reset_clock = time.monotonic()
long_clock = time.monotonic()
mode = "run"
mode_names = ["SHOW OZ?", " GRAMS?", " ZERO?", "CALIBRTE", " OFFSET?"]
stage = 0
zero_stage = 0
weight_avg = 0
zero_avg = 0
show_oz = True
show_grams = False
zero_out = False
calibrate_mode = False
blue_btn_pressed = False
green_btn_pressed = False
run_mode = True
avg_read = []
values = []
val_offset = 0
avg_values = []
for w in range(5):
nau7802.channel = 1
value = read_raw_value()
# takes value reading and divides with by the offset value
# to get the weight in grams
grams = value / calibration['offset_val']
avg_read.append(grams)
if len(avg_read) > 4:
the_avg = find_average(avg_read)
oz = the_avg / 28.35
display.print(" %0.1f oz" % oz)
avg_read.clear()
time.sleep(1)
while True:
# button debouncing
if blue_btn.value and blue_btn_pressed:
blue_btn_pressed = False
if green_btn.value and green_btn_pressed:
green_btn_pressed = False
green.value = False
# default run mode
# checks NAU7802 every 2 seconds
if run_mode is True and (time.monotonic() - clock) > 2:
nau7802.channel = 1
value = read_raw_value()
print(value)
value = abs(value) - val_offset
print(value)
#value = abs(value)
values.append(value)
# takes value reading and divides with by the offset value
# to get the weight in grams
grams = value / calibration['offset_val']
oz = grams / 28.35
if show_oz is True:
# append reading
avg_read.append(oz)
label = "oz"
if show_grams is True:
avg_read.append(grams)
label = "g"
print(avg_read)
if len(avg_read) > 10:
the_avg = find_average(avg_read)
display.print(" %0.1f %s" % (the_avg, label))
avg_read.clear()
val_offset += 10
clock = time.monotonic()
if (time.monotonic() - reset_clock) > 43200:
run_mode = False
show_oz = False
show_grams = False
zero_out = True
reset_clock = time.monotonic()
# if you press the change mode button
if (not green_btn.value and not green_btn_pressed) and run_mode:
green.value = True
# disables run mode (stops weighing)
run_mode = False
show_oz = False
show_grams = False
# mode is set to 0
mode = 0
# display shows the mode option
display.print(mode_names[mode])
blue.value = True
green_btn_pressed = True
# advances through the modes menu
if (not green_btn.value and not green_btn_pressed) and mode != "run":
green.value = True
# counts up to 4 and loops back to 0
mode = (mode+1) % 5
# updates display
display.print(mode_names[mode])
green_btn_pressed = True
# if you select show_oz
if (not blue_btn.value and not blue_btn_pressed) and mode == 0:
# show_oz is set as the state
show_oz = True
label = "oz"
blue.value = False
# goes back to weighing mode
mode = "run"
blue_btn_pressed = True
display.print(" %0.1f %s" % (the_avg, label))
run_mode = True
# if you select show_grams
if (not blue_btn.value and not blue_btn_pressed) and mode == 1:
# show_grams is set as the state
show_grams = True
label = "g"
blue.value = False
# goes back to weighing mode
mode = "run"
blue_btn_pressed = True
display.print(" %0.1f %s" % (the_avg, label))
run_mode = True
# if you select zero_out
if (not blue_btn.value and not blue_btn_pressed) and mode == 2:
# zero_out is set as the state
# can zero out the scale without full recalibration
zero_out = True
blue.value = False
mode = "run"
blue_btn_pressed = True
# if you select calibrate_mode
if (not blue_btn.value and not blue_btn_pressed) and mode == 3:
# calibrate_mode is set as the state
# starts up the calibration process
calibrate_mode = True
blue.value = False
mode = "run"
blue_btn_pressed = True
# if you select the offset
if (not blue_btn.value and not blue_btn_pressed) and mode == 4:
# displays the curren offset value stored in the code
blue.value = False
display.fill(0)
display.print("%0.4f" % calibration['offset_val'])
time.sleep(5)
mode = "run"
# goes back to weighing mode
show_oz = True
label = "oz"
display.print(" %0.1f %s" % (the_avg, label))
run_mode = True
blue_btn_pressed = True
# if the zero_out state is true
if zero_out and zero_stage == 0:
blue_btn_pressed = True
# clear the scale for zeroing
display.fill(0)
display.print("REMOVE ")
zero_stage = 1
blue.value = True
green.value = True
if (not blue_btn.value and not blue_btn_pressed) and zero_stage == 1:
green.value = False
# updates display
display.fill(0)
display.print("ZEROING")
blue.value = False
# runs zero_channel() function on both channels
nau7802.channel = 1
zero_channel()
display.fill(0)
display.print("ZEROED ")
zero_out = False
zero_stage = 0
# goes into weighing mode
val_offset = 0
run_mode = True
show_oz = True
label = "oz"
display.print(" %0.1f %s" % (the_avg, label))
# the calibration process
# each step is counted in stage
# blue button is pressed to advance to the next stage
if calibrate_mode is True and stage == 0:
blue_btn_pressed = True
# clear the scale for zeroing
display.fill(0)
display.print("REMOVE ")
stage = 1
blue.value = True
# stage 2
if (not blue_btn.value and not blue_btn_pressed) and stage == 1:
blue_btn_pressed = True
# runs the zero out function
display.fill(0)
display.print("ZEROING")
blue.value = False
nau7802.channel = 1
zero_channel()
display.fill(0)
display.print("ZEROED ")
stage = 2
blue.value = True
# stage 3
if (not blue_btn.value and not blue_btn_pressed) and stage == 2:
blue_btn_pressed = True
blue.value = False
display.print("STARTING")
blink(blue, 0.5, 3)
zero_readings = []
display.print("AVG ZERO")
# runs the calculateCallibration function
# takes 10 raw readings, stores them into an array and gets an average
zero_avg = calculateCalibration(zero_readings)
stage = 3
display.fill(0)
display.print("DONE")
blue.value = True
# stage 4
if (not blue_btn.value and not blue_btn_pressed) and stage == 3:
# place the known weight item
# item's weight matches calibration['weight'] in grams
blue_btn_pressed = True
blue.value = False
display.fill(0)
display.print("PUT ITEM")
stage = 4
blue.value = True
# stage 5
if (not blue_btn.value and not blue_btn_pressed) and stage == 4:
blue_btn_pressed = True
blue.value = False
display.fill(0)
display.print("WEIGHING")
weight_readings = []
# weighs the item 10 times, stores the readings in an array & averages them
weight_avg = calculateCalibration(weight_readings)
# calculates the new offset value
calibration['offset_val'] = (weight_avg-zero_avg) / calibration['weight']
display.marquee("%0.2f - CALIBRATED " % calibration['offset_val'], 0.3, False)
stage = 5
display.fill(0)
display.print("DONE")
blue.value = True
# final stage
if (not blue_btn.value and not blue_btn_pressed) and stage == 5:
blue_btn_pressed = True
zero_readings.clear()
weight_readings.clear()
calibrate_mode = False
blue.value = False
# goes back into weighing mode
show_oz = True
label = "oz"
display.print(" %0.1f %s" % (the_avg, label))
val_offset = 0
run_mode = True
# resets stage
stage = 0