change to NAU7802
This commit is contained in:
kolossos
GitHub
parent
8c5aaa00cc
commit
7e3839d667
|
|
@ -1,235 +1,20 @@
|
|||
#!/usr/bin/python
|
||||
# -*- coding: utf-8 -*-
|
||||
"""PiPyADC: Example file for class ADS1256 in module pipyadc:
|
||||
import nau7802py
|
||||
import time,os
|
||||
|
||||
ADS1256 cycling through eight input channels.
|
||||
|
||||
Default data rate changed to 100 SPS. Check if hardware is connected.
|
||||
Moving average filter over 32 samples.
|
||||
|
||||
Reading ADC sample data directly into a Numpy array as a buffer
|
||||
for further processing, e.g. FIR filter, PID control, ...
|
||||
|
||||
Hardware: Waveshare ADS1256 board interfaced to the Raspberry Pi 3
|
||||
|
||||
Ulrich Lukas 2017-03-10
|
||||
"""
|
||||
import sys,os
|
||||
sys.path.append('/opt/bienen/PiPyADC')
|
||||
|
||||
import time
|
||||
import numpy as np
|
||||
import itertools
|
||||
from ADS1256_definitions import *
|
||||
from pipyadc import ADS1256
|
||||
# In this example, we pretend myconfig_2 was a different configuration file
|
||||
# named "myconfig_2.py" for a second ADS1256 chip connected to the SPI bus.
|
||||
import ADS1256_tim01_config as myconfig_2
|
||||
myScale = nau7802py.NAU7802()
|
||||
|
||||
grafanaurl="%GRAFANA_URL%"
|
||||
|
||||
first=True
|
||||
### START EXAMPLE ###
|
||||
################################################################################
|
||||
### STEP 0: CONFIGURE CHANNELS AND USE DEFAULT OPTIONS FROM CONFIG FILE: ###
|
||||
#
|
||||
# For channel code values (bitmask) definitions, see ADS1256_definitions.py.
|
||||
# The values representing the negative and positive input pins connected to
|
||||
# the ADS1256 hardware multiplexer must be bitwise OR-ed to form eight-bit
|
||||
# values, which will later be sent to the ADS1256 MUX register. The register
|
||||
# can be explicitly read and set via ADS1256.mux property, but here we define
|
||||
# a list of differential channels to be input to the ADS1256.read_sequence()
|
||||
# method which reads all of them one after another.
|
||||
#
|
||||
# ==> Each channel in this context represents a differential pair of physical
|
||||
# input pins of the ADS1256 input multiplexer.
|
||||
#
|
||||
# ==> For single-ended measurements, simply select AINCOM as the negative input.
|
||||
#
|
||||
# AINCOM does not have to be connected to AGND (0V), but it is if the jumper
|
||||
# on the Waveshare board is set.
|
||||
#
|
||||
# Input pin for the potentiometer on the Waveshare Precision ADC board:
|
||||
POTI = POS_AIN0|NEG_AINCOM
|
||||
# Light dependant resistor of the same board:
|
||||
LDR = POS_AIN1|NEG_AINCOM
|
||||
# The other external input screw terminals of the Waveshare board:
|
||||
EXT2, EXT3, EXT4 = POS_AIN2|NEG_AINCOM, POS_AIN3|NEG_AIN4, POS_AIN4|NEG_AIN3
|
||||
EXT5, EXT6, EXT7 = POS_AIN5|NEG_AINCOM, POS_AIN6|NEG_AINCOM, POS_AIN7|NEG_AINCOM
|
||||
|
||||
# You can connect any pin as well to the positive as to the negative ADC input.
|
||||
# The following reads the voltage of the potentiometer with negative polarity.
|
||||
# The ADC reading should be identical to that of the POTI channel, but negative.
|
||||
POTI_INVERTED = POS_AINCOM|NEG_AIN0
|
||||
|
||||
# For fun, connect both ADC inputs to the same physical input pin.
|
||||
# The ADC should always read a value close to zero for this.
|
||||
SHORT_CIRCUIT = POS_AIN0|NEG_AIN0
|
||||
|
||||
# Specify here an arbitrary length list (tuple) of arbitrary input channel pair
|
||||
# eight-bit code values to scan sequentially from index 0 to last.
|
||||
# Eight channels fit on the screen nicely for this example..
|
||||
#CH_SEQUENCE = (POTI, LDR, EXT2, EXT3, EXT4, EXT7, POTI_INVERTED, SHORT_CIRCUIT)
|
||||
CH_SEQUENCE = (EXT3,)
|
||||
################################################################################
|
||||
|
||||
########################## CALIBRATION CONSTANTS ############################
|
||||
# This shows how to use individual channel calibration values.
|
||||
#
|
||||
# The ADS1256 has internal gain and offset calibration registers, but these are
|
||||
# applied to all channels without making any difference.
|
||||
# I we want to use individual calibration values, e.g. to compensate external
|
||||
# circuitry parasitics, we can do this very easily in software.
|
||||
# The following values are only for demonstration and have no meaning.
|
||||
CH_OFFSET = np.array((-10, 0, -85, 0, 750, 0, 0, 0), dtype=np.int)
|
||||
GAIN_CAL = np.array((1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0), dtype=np.float)
|
||||
################################################################################
|
||||
|
||||
# Using the Numpy library, digital signal processing is easy as (Raspberry) Pi..
|
||||
# However, this constant only specifies the length of a moving average.
|
||||
FILTER_SIZE = 2
|
||||
################################################################################
|
||||
|
||||
|
||||
def do_measurement():
|
||||
### STEP 1: Initialise ADC objects for two chips connected to the SPI bus.
|
||||
# In this example, we pretend myconfig_2 was a different configuration file
|
||||
# named "myconfig_2.py" for a second ADS1256 chip connected to the SPI bus.
|
||||
# This file must be imported, see top of the this file.
|
||||
# Omitting the first chip here, as this is only an example.
|
||||
|
||||
#ads1 = ADS1256(myconfig_1)
|
||||
# (Note1: See ADS1256_default_config.py, see ADS1256 datasheet)
|
||||
# (Note2: Input buffer on means limited voltage range 0V...3V for 5V supply)
|
||||
ads2 = ADS1256(myconfig_2)
|
||||
|
||||
# Just as an example: Change the default sample rate of the ADS1256:
|
||||
# This shows how to acces ADS1256 registers via instance property
|
||||
ads2.drate = DRATE_2_5
|
||||
ads2.pga_gain = 64
|
||||
#ads2.mux = POS_AIN4 | NEG_AIN3
|
||||
### STEP 2: Gain and offset self-calibration:
|
||||
ads2.cal_self()
|
||||
|
||||
### Get ADC chip ID and check if chip is connected correctly.
|
||||
chip_ID = ads2.chip_ID
|
||||
print("\nADC No. 2 reported a numeric ID value of: {}.".format(chip_ID))
|
||||
# When the value is not correct, user code should exit here.
|
||||
if chip_ID != 3:
|
||||
print("\nRead incorrect chip ID for ADS1256. Is the hardware connected?")
|
||||
# Passing that step because this is an example:
|
||||
# sys.exit(1)
|
||||
|
||||
# Channel gain must be multiplied by LSB weight in volts per digit to
|
||||
# display each channels input voltage. The result is a np.array again here:
|
||||
CH_GAIN = ads2.v_per_digit * GAIN_CAL
|
||||
|
||||
# Numpy 2D array as buffer for raw input samples. Each row is one complete
|
||||
# sequence of samples for eight input channel pin pairs. Each column stores
|
||||
# the number of FILTER_SIZE samples for each channel.
|
||||
rows, columns = FILTER_SIZE, len(CH_SEQUENCE)
|
||||
filter_buffer = np.zeros((rows, columns), dtype=np.int)
|
||||
|
||||
# Fill the buffer first once before displaying continuously updated results
|
||||
print("Channels configured: {}\n"
|
||||
"Initializing filter (this can take a minute)...".format(
|
||||
len(CH_SEQUENCE)))
|
||||
for row_number, data_row in enumerate(filter_buffer):
|
||||
# Do the data acquisition of eight multiplexed input channels.
|
||||
# The ADS1256 read_sequence() method automatically fills into
|
||||
# the buffer specified as the second argument:
|
||||
ads2.read_sequence(CH_SEQUENCE, data_row)
|
||||
# Depending on aquisition speed and filter lenth, this can take long...
|
||||
sys.stdout.write(
|
||||
"\rProgress: {:3d}%".format(int(100*(row_number+1)/FILTER_SIZE)))
|
||||
sys.stdout.flush()
|
||||
|
||||
|
||||
# From now, update filter_buffer cyclically with new ADC samples and
|
||||
# calculate results with averaged results.
|
||||
print("\n\nOutput values averaged over {} ADC samples:".format(FILTER_SIZE))
|
||||
# The following is an endless loop!
|
||||
timestamp = time.time() # Limit output data rate to fixed time interval
|
||||
for data_row in itertools.cycle(filter_buffer):
|
||||
#
|
||||
# Do the data acquisition of eight multiplexed input channels
|
||||
#
|
||||
# The result channel values are directy read into the array specified
|
||||
# as the second argument, which must be a mutable type.
|
||||
ads2.read_sequence(CH_SEQUENCE, data_row)
|
||||
|
||||
elapsed = time.time() - timestamp
|
||||
if elapsed > .1:
|
||||
timestamp += .1
|
||||
|
||||
# Calculate moving average of input samples, subtract offset
|
||||
ch_unscaled = np.average(filter_buffer, axis=0) - CH_OFFSET
|
||||
ch_volts = ch_unscaled * CH_GAIN
|
||||
|
||||
to_grafana([int(i) for i in ch_unscaled], ch_volts)
|
||||
|
||||
### END EXAMPLE ###
|
||||
|
||||
|
||||
#############################################################################
|
||||
# Format nice looking text output:
|
||||
def nice_output(digits, volts):
|
||||
sys.stdout.write(
|
||||
"\0337" # Store cursor position
|
||||
+
|
||||
"""These are the raw sample values for the channels:
|
||||
Poti_CH0, LDR_CH1, AIN2, AIN3, AIN4, AIN7, Poti NEG, Short 0V
|
||||
"""
|
||||
+ ", ".join(["{: 8d}".format(i) for i in digits])
|
||||
+
|
||||
"""
|
||||
|
||||
These are the sample values converted to voltage in V for the channels:
|
||||
Poti_CH0, LDR_CH1, AIN2, AIN3, AIN4, AIN7, Poti NEG, Short 0V
|
||||
"""
|
||||
+ ", ".join(["{: 8.3f}".format(i) for i in volts])
|
||||
+ "\n\033[J\0338" # Restore cursor position etc.
|
||||
)
|
||||
|
||||
def tim_nice_output(digits, volts):
|
||||
global first
|
||||
global res0
|
||||
res=float(85.5+64000*volts[0:1])
|
||||
if first:
|
||||
res0=res
|
||||
res=res-res0
|
||||
first=False
|
||||
sys.stdout.write(
|
||||
"\0337" # Store cursor position
|
||||
+ "{: 8.4f}".format(res)
|
||||
+ "\n\033[J\0338" # Restore cursor position etc.
|
||||
)
|
||||
|
||||
def to_grafana(digits, volts):
|
||||
global first
|
||||
global res0
|
||||
res=float(.63+7.5/5*6400*volts[0:1])
|
||||
|
||||
sys.stdout.write(
|
||||
"\0337" # Store cursor position
|
||||
+ "{: 8.4f}".format(res)
|
||||
+ "\n\033[J\0338" # Restore cursor position etc.
|
||||
)
|
||||
try:
|
||||
os.system("curl -i -XPOST '"+grafanaurl+"' --data-binary 'weight,location=bees01 value="+str(res)+"'")
|
||||
except:
|
||||
print("no access to grafana?")
|
||||
pass
|
||||
time.sleep(5)
|
||||
|
||||
# Start data acquisition
|
||||
try:
|
||||
print("\033[2J\033[H") # Clear screen
|
||||
print(__doc__)
|
||||
print("\nPress CTRL-C to exit.")
|
||||
do_measurement()
|
||||
|
||||
except (KeyboardInterrupt):
|
||||
print("\n"*8 + "User exit.\n")
|
||||
|
||||
|
||||
if myScale.begin():
|
||||
while True:
|
||||
currentReading = myScale.getReading()
|
||||
currentWeight = myScale.getWeight()
|
||||
print('Reading: ' + str(currentReading)+" "+ str(round(currentWeight, 4)))
|
||||
try:
|
||||
cmd="curl -i -XPOST '"+grafanaurl+"' --data-binary 'weight,location=bees01 value="+str(currentWeight)+"'"
|
||||
print (cmd)
|
||||
os.system(cmd)
|
||||
except:
|
||||
print("no access to grafana?")
|
||||
pass
|
||||
time.sleep(1)
|
||||
|
|
|
|||
Loading…
Reference in New Issue