An easy-to-use Python script for connecting a Raspberry Pi-based PM2.5 monitor to the LASS system.
While a stand-alone AirBox is cool, using a Raspberry Pi to power it is a bit of overkill for something that you put and forget. A simple, reliable, industrial micro-controller (Arduino or other) is more desirable for a put-and-forget airbox that you install and leave somewhere.
The goal here is to find a way to take full advantage of the Raspberry Pi’s capability in order to do something better.
Raspberry pi has several important advantages, and PiM25 software’s goal is to make all of these advantages available
You can:
- Have multiple, virtual boxes
- Compare different sensors head-to-head in real time.
- Do local logging, or electronic reporting of sensors beyond those needed for a standard AirBox report. They allow for many, and for mobile and battery operated support (battery level, battery charge/discharge, motion speed, CPU usage percent) as well as additional sensors beyond (PM1, 2.5, 10, temp, humid) like
- add toxic and irritating gasses
- light levels
- radiation
- rain and precipitation
- barometric pressure
- loud noises
- wind speed and direction
Multiple, virtual LASS boxes to support multiple sensor sets in the same location
How to “build a box”.
There are a few ways.
-
You can write a standard, simple python script. Make a box instance, then make sensor instances from it.
-
You can do it interactively from a Python prompt. Similarly to the script, make a box instance, then make sensor instances from it.
-
Generate the whole thing predefined in a .yaml dictionary. Use PiM25.PiM25YAMLreader(‘filename.yaml’)
You can also combine any or all of the above!
$ sudo apt-get update
$ sudo apt-get install -y python-dev python-pip python-matplotlib mosquitto mosquitto-clients
$ sudo pip install numpy paho-mqtt psutil ymlconfig pynmea2 requests
$ sudo pip3 install paho-mqttOnce you are done, you can SAVE your configuration as a .yaml file using PiM25.PiM25YAMLwriter(‘filename.yaml’) That way you can “rebuild” your box the next time you start your project, exactly as it existed when you were last developing it.
METHOD 1: Python script.
from PiM25_UPDATED import BOX import time from itertools import cycle import matplotlib.pyplot as plt
box = BOX('my box', use_WiFi=True, use_SMBus=True, use_pigpio=True)
dht = box.new_DHT22bb('my dht', DATA=17, POWER=27)
g3 = box.new_G3bb('my dht', DATA=24, collect_time=3.0)
adc = box.new_MCP3008bbspi('my adc',CSbar=26, MISO=13, MOSI=19, SCLK=6, Vref=3.3 )
CO = box.new_MOS_gas_sensor('my CO sensor', ADC='my adc', channel=1, Rseries=1000, Calibrationdata=[[10,5000],[100,2200],[1000,777]], logCalibrationdata=[[10,5000],[100,2200],[1000,777]], use_loglog=False, gasname='CO')
oled = box.new_OLEDi2c('my oled')
s1 = oled.new_screen('T and H')
s1.new_field('temp', [2, 5], wh=[120, 24], fmt='T(C) {0:.1f}', fontdef='Arial Unicode.ttf', fontsize=20, info=[[dht, 'temperature']]) s1.new_field('humid', [2, 35], wh=[120, 24], fmt='H(%) {0:.1f}', fontdef='Arial Unicode.ttf', fontsize=20, info=[[dht, 'humidity']])
s2 = oled.new_screen('particles')
s2.new_field('PMbig', [2, 5], wh=[120, 24], fmt='PM25 {0:.0f}', fontdef='Arial Unicode.ttf', fontsize=20, info=((g3, 'PM25'),)) s2.new_field('PMsmall', [2, 35], wh=[120, 24], fmt='PM1 {0:.0f}, PM10 {0:.0f}', fontdef='default', fontsize=20, info=((g3, 'PM1'), (g3, 'PM10')))
s3 = oled.new_screen('gasses')
s3.new_field('COa', [2, 30], wh=[120, 24], fmt='CO (ppm) {0:.1f}', fontdef='Arial Unicode.ttf', fontsize=18, info=((CO, 'ppm'),))
oled.initiate() oled.display_on() for thing in ('show_white', 'show_black', 'show_gray'): getattr(oled, thing)()
wait = 7. # seconds
while True:
oled.show_gray()
dht.read()
g3.read()
adc.digitize_one_channel(1)
CO.read()
# or just use box.read_all()
# lass.build_and_send_to_LASS()
# print lass.LASS_string
for s in oled.screens:
s.update_all()
tnext = time.time() + wait
screenz = cycle(oled.screens)
while time.time() < tnext:
s = screenz.next()
oled.show_screen(s)
time.sleep(1.5)
METHOD 2: Python interactive. should be similar or identical, just typed line-by-line
METHOD 3: .yaml definition.
my box:
args: {'use_WiFi': True, 'use_pigpio': True, 'use_SMBus': True}
LASS devices:
my LASS:
static location: {'latlon':[25.03366, 121.564841], 'alt':550.0}
sources: {'humsrc':'my dht', 'tempsrc':'my dht', 'pm1src':'my gthree', 'pm25src':'my gthree', 'pm10src':'my gthree',
'timedatesrc':'system', 'GPSsrc':'static', 'gassensors':[]}
GPIO devices:
my dht:
method: new_DHT22bb
args: {'DATA':17, 'POWER':27}
my gthree:
method: new_G3bb
args: {'DATA':24, 'collect_time':3.0}
my oled:
method: new_OLEDi2c
screens:
T and H:
fields:
temp:
args: {'wh':[120, 24],
'fmt':'T(C) {0:.1f}', 'fontdef':'Arial Unicode.ttf',
'fontsize':20, 'info':[['my dht', 'temperature']]}
xy0: [2, 5]
humid:
args: {'wh':[120, 24],
'fmt':'H(%) {0:.1f}', 'fontdef':'Arial Unicode.ttf',
'fontsize':20, 'info':[['my dht', 'humidity']]}
xy0: [2, 35]
particles:
fields:
PMbig:
args: {'wh':[120, 24],
'fmt':'PM25 {0:.0f}', 'fontdef':'Arial Unicode.ttf',
'fontsize':20, 'info':[['my gthree', 'PM25']]}
xy0: [2, 5]
PMsmall:
args: {'wh':[120, 24],
'fmt':'PM1 {0:.0f}, PM10 {0:.0f}', 'fontdef':'default',
'info':[['my gthree', 'PM1'], ['my gthree', 'PM10']]}
xy0: [2, 35]
And the python to run it is currently like this. In the next version, it will be completely automated
boxes = reader('mybox_documentation.yaml')
box = boxes[0]
lass = box.LASS_devices[0]
log = box.LOG_devices[0]
box.get_device('my oled').initiate()
box.get_device('my oled').display_on()
box.get_device('my oled').show_gray()
# Define your loop for operation
wait = 10. # seconds
# Go!
while True:
box.read_all()
lass.build_and_send_to_LASS()
# print lass.LASS_string
log.build_and_save_entry()
for s in oled.screens():
s.update_all()
tnext = time.time() + wait
screenz = cycle(box.screens)
while time.time() < tnext:
s = next(screenz)
oled.show_screen(s)
time.sleep(1)
Here is a quick review of python methods:
BOX
.clear_all_device_datadicts()
.read_all_devices()
.get_system_timedate_dict()
.make_a_pi()
.WiFi_setstatus()
.get_WiFi_is_on()
.WiFi_on()
.WiFi_off()
.get_mac_address()
.print_some_system_info()
.get_system_datetime()
.show_CPU_temp()
.get_system_datetime()
.add_device(dev)
# some wrappers…..
.new_Dummy()
.new_DHT22bb()
.new_G3bb()
.new_GPSbb()
.new_MCP3008bbspi()
.new_MOS_gas_sensor()
.new_OLEDi2c()
.new_LASS()
.new_LOG()
.get_system_datetime()
LASS
.set_static_location(latlon, alt)
.set_sources(self, humsrc=None, tempsrc=None, pm25src=None,
pm1src=None, pm10src=None, timedatesrc=None,
GPSsrc=None, gassensors=None)
.build_entry()
.send_to_LASS()
.view_LASS_entry()
LOG
.configure()
.build_entry()
.save_entry()
GPIO_DEVICE
.get_my_current_instance_info()
.get_my_original_instance_info()
Dummy
.read()
DHT22bb
.read()
.cancel()
MCP3008bbSPI
.digitize_one_channel()
.measure_one_voltage()
MOS_gas_sensor_ppm()
.read()
MOS_gas_sensor
.read()
RTCi2c
.read()
.set_time()
G3bb
.read()
GPSbb
.read()
OLEDi2c
.new_screen()
.add_screen(screen object)
.initiate()
.display_on()
.set_contrast()
.show_black()
.show_white()
.show_gray()
.show_screen(screen object)
.update_all_and_show_screen(screen object)
.show_array()
.preview_me()
SCREEN
.__init__()
.__repr__()
.new_field()
.add_field()
.update_all()
.preview_me()
.update_all_and_preview_me()
FIELD
.__init__()
.__repr__()
.update()
.preview_me()