Data not being received from DHT22 Temperature/Humidity Sensor

[Michael Grossie]

Pardon - this topic was started in thread called - Unable to start weewx - with ADS-WS1 Station

Raspberry Pi 2B+

Installed with setup.py

WS1 Weather Station

Weewx 4.1.1

Extra Sensor - Adafruit DHT22 - Temperature and humidity sensor.

Service - Extra_sensors_service - located in /home/weewx/bin/user

(frame work for the above file from a script that used a BMP085/180)

I am trying to gather the data from the Adafruit DHT22 and insert it into the "outTemp" and the "outHumidity" columns of the archive.sdb.  The "driver" or "service" is based on one that I found on Github for the BMP085/180.

I can see that data is being received in a csv file that I wrote a script for (with the help of script I found on Raspberrypi.org). 

I can see in the Loop Data that both outTemp and outHumidity are listed but they have no data associated with them.

I thought about just parsing the data from the csv with fileparse, but since I can't seem to get this service script to work, I don't have much confidence that I can make it work with file parse.

Below are the weewx.conf files and the extra_sensors_service script.  

==================

# WEEWX CONFIGURATION FILE

#

# Copyright (c) 2009-2019 Tom Keffer <tkeffer>

# See the file LICENSE.txt for your rights.

##############################################################################

# This section is for general configuration information.

# Set to 1 for extra debug info, otherwise comment it out or set to zero

debug = 1

# Root directory of the weewx data file hierarchy for this station

WEEWX_ROOT = /home/weewx

# Whether to log successful operations

log_success = True

# Whether to log unsuccessful operations

log_failure = True

# How long to wait before timing out a socket (FTP, HTTP) connection

socket_timeout = 20

# Do not modify this. It is used when installing and updating weewx.

version = 4.1.1

##############################################################################

#   This section is for information about the station.

[Station]

    

    # Description of the station location

    location = "Casita - Yuma, AZ"

    

    # Latitude in decimal degrees. Negative for southern hemisphere

    latitude = 31.6288

    # Longitude in decimal degrees. Negative for western hemisphere.

    longitude = -114.4056

    

    # Altitude of the station, with unit it is in. This is downloaded from

    # from the station if the hardware supports it.

    altitude = 424, foot    # Choose 'foot' or 'meter' for unit

    

    # Set to type of station hardware. There must be a corresponding stanza

    # in this file with a 'driver' parameter indicating the driver to be used.

    station_type = WS1

    

    # If you have a website, you may specify an URL

    station_url = http://www.grossie.???

    

    # The start of the rain year (1=January; 10=October, etc.). This is

    # downloaded from the station if the hardware supports it.

    rain_year_start = 1

    

    # Start of week (0=Monday, 6=Sunday)

    week_start = 6

##############################################################################

[WS1]

    # This section is for the ADS WS1 series of weather stations.

    

    # Driver mode - tcp, udp, or serial

    mode = serial

    

    # If serial, specify the serial port device. (ex. /dev/ttyS0, /dev/ttyUSB0,

    # or /dev/cuaU0)

    # If TCP, specify the IP address and port number. (ex. 192.168.36.25:3000)

    port = /dev/ttyUSB0

    

    # The amount of time, in seconds, before the connection fails if there is

    # no response

    timeout = 10

    

    # The driver to use:

    driver = weewx.drivers.ws1

##############################################################################

[Simulator]

    # This section is for the weewx weather station simulator

    

    # The time (in seconds) between LOOP packets.

    loop_interval = 2.5

    

    # The simulator mode can be either 'simulator' or 'generator'.

    # Real-time simulator. Sleep between each LOOP packet.

    mode = simulator

    # Generator.  Emit LOOP packets as fast as possible (useful for testing).

    #mode = generator

    

    # The start time. Format is YYYY-mm-ddTHH:MM. If not specified, the default 

    # is to use the present time.

    #start = 2011-01-01T00:00

    

    # The driver to use:

    driver = weewx.drivers.simulator

##############################################################################

#   This section is for uploading data to Internet sites

[StdRESTful]

    

    [[StationRegistry]]

        # To register this weather station with weewx, set this to true

        register_this_station = true

    

    [[AWEKAS]]

        # This section is for configuring posts to AWEKAS.

        

        # If you wish to do this, set the option 'enable' to true,

        # and specify a username and password.

        # To guard against parsing errors, put the password in quotes.

        enable = false

        username = replace_me

        password = replace_me

    

    [[CWOP]]

        # This section is for configuring posts to CWOP.

        

        # If you wish to do this, set the option 'enable' to true,

        # and specify the station ID (e.g., CW1234).

        enable = false

        station = replace_me

    

    # If this is an APRS (radio amateur) station, uncomment

    # the following and replace with a passcode (e.g., 12345).

    #passcode = replace_me (APRS stations only)

    

    [[PWSweather]]

        # This section is for configuring posts to PWSweather.com.

        

        # If you wish to do this, set the option 'enable' to true,

        # and specify a station and password.

        # To guard against parsing errors, put the password in quotes.

        enable = false

        station = replace_me

        password = replace_me

    

    [[WOW]]

        # This section is for configuring posts to WOW.

        

        # If you wish to do this, set the option 'enable' to true,

        # and specify a station and password.

        # To guard against parsing errors, put the password in quotes.

        enable = false

        station = replace_me

        password = replace_me

    

    [[Wunderground]]

        # This section is for configuring posts to the Weather Underground.

        

        # If you wish to do this, set the option 'enable' to true,

        # and specify a station (e.g., 'KORHOODR3') and password.

        # To guard against parsing errors, put the password in quotes.

        enable = false

        station = replace_me

        password = replace_me

        

        # If you plan on using wunderfixer, set the following

        # to your API key:

        api_key = replace_me

        

        # Set the following to True to have weewx use the WU "Rapidfire"

        # protocol. Not all hardware can support it. See the User's Guide.

        rapidfire = False

##############################################################################

#   This section specifies what reports, using which skins, to generate.

[StdReport]

    

    # Where the skins reside, relative to WEEWX_ROOT

    SKIN_ROOT = skins

    

    # Where the generated reports should go, relative to WEEWX_ROOT

    HTML_ROOT = public_html

    

    # The database binding indicates which data should be used in reports.

    data_binding = wx_binding

    

    # Whether to log a successful operation

    log_success = True

    

    # Whether to log an unsuccessful operation

    log_failure = False

    

    # Each of the following subsections defines a report that will be run.

    # See the customizing guide to change the units, plot types and line

    # colors, modify the fonts, display additional sensor data, and other

    # customizations. Many of those changes can be made here by overriding

    # parameters, or by modifying templates within the skin itself.

    

    [[SeasonsReport]]

        # The SeasonsReport uses the 'Seasons' skin, which contains the

        # images, templates and plots for the report.

        skin = Seasons

        enable = true

    

    [[SmartphoneReport]]

        # The SmartphoneReport uses the 'Smartphone' skin, and the images and

        # files are placed in a dedicated subdirectory.

        skin = Smartphone

        enable = true

        HTML_ROOT = public_html/smartphone

    

    [[MobileReport]]

        # The MobileReport uses the 'Mobile' skin, and the images and files

        # are placed in a dedicated subdirectory.

        skin = Mobile

        enable = true

        HTML_ROOT = public_html/mobile

    

    [[StandardReport]]

        # This is the old "Standard" skin. By default, it is not enabled.

        skin = Standard

        enable = false

    

    [[FTP]]

        # FTP'ing the results to a webserver is treated as just another report,

        # albeit one with an unusual report generator!

        skin = Ftp

        

        # If you wish to use FTP, set "enable" to "true", then

        # fill out the next four lines.

        # Use quotes around passwords to guard against parsing errors.

        enable = false

        user = replace_me

        password = replace_me

        server = replace_me    # The ftp server name, e.g, www.myserver.org

        path = replace_me    # The destination directory, e.g., /weather

        

        # Set to True for an FTP over TLS (FTPS) connection. Not all servers

        # support this.

        secure_ftp = False

        

        # To upload files from something other than what HTML_ROOT is set

        # to above, specify a different HTML_ROOT here.

        #HTML_ROOT = public_html

        

        # Most FTP servers use port 21

        port = 21

        

        # Set to 1 to use passive mode, zero for active mode

        passive = 1

    

    [[RSYNC]]

        # rsync'ing to a webserver is treated as just another report

        skin = Rsync

        

        # If you wish to use rsync, you must configure passwordless ssh using

        # public/private key authentication from the user account that weewx

        # runs to the user account on the remote machine where the files

        # will be copied.

        #

        # If you wish to use rsync, set "enable" to "true", then

        # fill out server, user, and path.

        # The server should appear in your .ssh/config file.

        # The user is the username used in the identity file.

        # The path is the destination directory, such as /var/www/html/weather.

        # Be sure that the user has write permissions on the destination!

        enable = false

        server = replace_me

        user = replace_me

        path = replace_me

        

        # To upload files from something other than what HTML_ROOT is set

        # to above, specify a different HTML_ROOT here.

        #HTML_ROOT = public_html

        

        # Rsync can be configured to remove files from the remote server if

        # they don't exist under HTML_ROOT locally. USE WITH CAUTION: if you

        # make a mistake in the remote path, you could could unintentionally

        # cause unrelated files to be deleted. Set to 1 to enable remote file

        # deletion, zero to allow files to accumulate remotely.

        delete = 0

    

    ####

    

    # Various options for customizing your reports.

    

    [[Defaults]]

        

        [[[Units]]]

            

            # The following section sets what unit to use for each unit group.

            # NB: The unit is always in the singular. I.e., 'mile_per_hour',

            # NOT 'miles_per_hour'

            [[[[Groups]]]]

                

                group_altitude = foot    # Options are 'foot' or 'meter'

                group_degree_day = degree_F_day    # Options are 'degree_F_day' or 'degree_C_day'

                group_distance = mile    # Options are 'mile' or 'km'

                group_pressure = inHg    # Options are 'inHg', 'mmHg', 'mbar', or 'hPa'

                group_rain = inch    # Options are 'inch', 'cm', or 'mm'

                group_rainrate = inch_per_hour    # Options are 'inch_per_hour', 'cm_per_hour', or 'mm_per_hour'

                group_speed = mile_per_hour    # Options are 'mile_per_hour', 'km_per_hour', 'knot', or 'meter_per_second'

                group_speed2 = mile_per_hour2    # Options are 'mile_per_hour2', 'km_per_hour2', 'knot2', or 'meter_per_second2'

                group_temperature = degree_F    # Options are 'degree_F' or 'degree_C'

            

            # The following section sets the formatting for each type of unit.

            [[[[StringFormats]]]]

                

                centibar = %.0f

                cm = %.2f

                cm_per_hour = %.2f

                degree_C = %.1f

                degree_F = %.1f

                degree_compass = %.0f

                foot = %.0f

                hPa = %.1f

                hour = %.1f

                inHg = %.3f

                inch = %.2f

                inch_per_hour = %.2f

                km = %.1f

                km_per_hour = %.0f

                km_per_hour2 = %.1f

                knot = %.0f

                knot2 = %.1f

                mbar = %.1f

                meter = %.0f

                meter_per_second = %.1f

                meter_per_second2 = %.1f

                mile = %.1f

                mile_per_hour = %.0f

                mile_per_hour2 = %.1f

                mm = %.1f

                mmHg = %.1f

                mm_per_hour = %.1f

                percent = %.0f

                second = %.0f

                uv_index = %.1f

                volt = %.1f

                watt_per_meter_squared = %.0f

                NONE = "   N/A"

            

            # The following section overrides the label used for each type of unit

            [[[[Labels]]]]

                

                meter = " meter", " meters"    # You may prefer "metre".

                day = " day", " days"

                hour = " hour", " hours"

                minute = " minute", " minutes"

                second = " second", " seconds"

                NONE = ""

            

            # The following section sets the format for each time scale.

            # The values below will work in every locale, but they may not look

            # particularly attractive.

            [[[[TimeFormats]]]]

                

                hour = %H:%M

                day = %X

                week = %X (%A)

                month = %x %X

                year = %x %X

                rainyear = %x %X

                current = %x %X

                ephem_day = %X

                ephem_year = %x %X

            

            [[[[Ordinates]]]]

                

                # Ordinal directions. The last one is for no wind direction

                directions = N, NNE, NE, ENE, E, ESE, SE, SSE, S, SSW, SW, WSW, W, WNW, NW, NNW, N/A

            

            # The following section sets the base temperatures used for the

            #  calculation of heating, cooling, and growing degree-days.

            [[[[DegreeDays]]]]

                

                # Base temperature for heating days, with unit:

                heating_base = 65, degree_F

                # Base temperature for cooling days, with unit:

                cooling_base = 65, degree_F

                # Base temperature for growing days, with unit:

                growing_base = 50, degree_F

            

            # A trend takes a difference across a time period. The following

            # section sets the time period, and how big an error is allowed to

            # still be counted as the start or end of a period.

            [[[[Trend]]]]

                

                time_delta = 10800    # 3 hours

                time_grace = 300    # 5 minutes

        

        # The labels to be used for each observation type

        [[[Labels]]]

            

            # Set to hemisphere abbreviations suitable for your location:

            hemispheres = N, S, E, W

            

            # Formats to be used for latitude whole degrees, longitude whole

            # degrees, and minutes:

            latlon_formats = %02d, %03d, %05.2f

            

            # Generic labels, keyed by an observation type.

            [[[[Generic]]]]

                barometer = Barometer

                dewpoint = Dew Point

                ET = ET

                heatindex = Heat Index

                inHumidity = Inside Humidity

                inTemp = Inside Temperature

                outHumidity = Humidity

                outTemp = Outside Temperature

                radiation = Radiation

                rain = Rain

                rainRate = Rain Rate

                UV = UV Index

                windDir = Wind Direction

                windGust = Gust Speed

                windGustDir = Gust Direction

                windSpeed = Wind Speed

                windchill = Wind Chill

                windgustvec = Gust Vector

                windvec = Wind Vector

                extraTemp1 = Temperature1

                extraTemp2 = Temperature2

                extraTemp3 = Temperature3

                

                # Sensor status indicators

                

                rxCheckPercent = Signal Quality

                txBatteryStatus = Transmitter Battery

                windBatteryStatus = Wind Battery

                rainBatteryStatus = Rain Battery

                outTempBatteryStatus = Outside Temperature Battery

                inTempBatteryStatus = Inside Temperature Battery

                consBatteryVoltage = Console Battery

                heatingVoltage = Heating Battery

                supplyVoltage = Supply Voltage

                referenceVoltage = Reference Voltage

        

        [[[Almanac]]]

            

            # The labels to be used for the phases of the moon:

            moon_phases = New, Waxing crescent, First quarter, Waxing gibbous, Full, Waning gibbous, Last quarter, Waning crescent

##############################################################################

#   This service acts as a filter, converting the unit system coming from

#   the hardware to a unit system in the database.

[StdConvert]

    

    # The target_unit affects only the unit system in the database. Once

    # chosen it cannot be changed without converting the entire database.

    # Modification of target_unit after starting weewx will result in

    # corrupt data - the database will contain a mix of US and METRIC data.

    #

    # The value of target_unit does not affect the unit system for

    # reporting - reports can display US, Metric, or any combination of units.

    #

    # In most cases, target_unit should be left as the default: US

    #

    # In particular, those migrating from a standard wview installation

    # should use US since that is what the wview database contains.

    

    # DO NOT MODIFY THIS VALUE UNLESS YOU KNOW WHAT YOU ARE DOING!

    target_unit = US    # Options are 'US', 'METRICWX', or 'METRIC'

##############################################################################

#   This section can adjust data using calibration expressions.

[StdCalibrate]

    

    [[Corrections]]

        # For each type, an arbitrary calibration expression can be given.

        # It should be in the units defined in the StdConvert section.

        # Example:

        foo = foo + 0.2

##############################################################################

#   This section is for quality control checks. If units are not specified,

#   values must be in the units defined in the StdConvert section.

[StdQC]

    

    [[MinMax]]

        barometer = 26, 32.5, inHg

        pressure = 24, 34.5, inHg

        outTemp = -40, 120, degree_F

        inTemp = 10, 120, degree_F

        outHumidity = 0, 100

        inHumidity = 0, 100

        windSpeed = 0, 120, mile_per_hour

        rain = 0, 10, inch

##############################################################################

#   This section controls the origin of derived values.

[StdWXCalculate]

    

    [[Calculations]]

        # How to calculate derived quantities.  Possible values are:

        #  hardware        - use the value provided by hardware

        #  software        - use the value calculated by weewx

        #  prefer_hardware - use value provide by hardware if available,

        #                      otherwise use value calculated by weewx

        

        pressure = prefer_hardware

        altimeter = prefer_hardware

        appTemp = prefer_hardware

        barometer = prefer_hardware

        beaufort = prefer_hardware

        cloudbase = prefer_hardware

        dewpoint = prefer_hardware

        ET = prefer_hardware

        heatindex = prefer_hardware

        humidex = prefer_hardware

        inDewpoint = prefer_hardware

        maxSolarRad = prefer_hardware

        rainRate = prefer_hardware

        windchill = prefer_hardware

        windrun = prefer_hardware

##############################################################################

#   For hardware that supports it, this section controls how often the

#   onboard clock gets updated.

[StdTimeSynch]

    

    # How often to check the weather station clock for drift (in seconds)

    clock_check = 14400

    

    # How much it can drift before we will correct it (in seconds)

    max_drift = 5

##############################################################################

#   This section is for configuring the archive service.

[StdArchive]

    

    # If the station hardware supports data logging then the archive interval

    # will be downloaded from the station. Otherwise, specify it (in seconds).

    archive_interval = 300

    

    # If possible, new archive records are downloaded from the station

    # hardware. If the hardware does not support this, then new archive

    # records will be generated in software.

    # Set the following to "software" to force software record generation.

    record_generation = hardware

    

    # Whether to include LOOP data in hi/low statistics

    loop_hilo = True

    

    # The data binding used to save archive records

    data_binding = wx_binding

##############################################################################

#   This section binds a data store to a database.

[DataBindings]

    

    [[wx_binding]]

        # The database must match one of the sections in [Databases].

        # This is likely to be the only option you would want to change.

        database = archive_sqlite

        # The name of the table within the database

        table_name = archive

        # The manager handles aggregation of data for historical summaries

        manager = weewx.manager.DaySummaryManager

        # The schema defines the structure of the database.

        # It is *only* used when the database is created.

        schema = schemas.wview_extended.schema

##############################################################################

#   This section defines various databases.

[Databases]

    

    # A SQLite database is simply a single file

    [[archive_sqlite]]

        database_name = weewx.sdb

        database_type = SQLite

    

    # MySQL

    [[archive_mysql]]

        database_name = weewx

        database_type = MySQL

##############################################################################

#   This section defines defaults for the different types of databases.

[DatabaseTypes]

    

    # Defaults for SQLite databases

    [[SQLite]]

        driver = weedb.sqlite

        # Directory in which the database files are located

        SQLITE_ROOT = %(WEEWX_ROOT)s/archive

    

    # Defaults for MySQL databases

    [[MySQL]]

        driver = weedb.mysql

        # The host where the database is located

        host = localhost

        # The user name for logging in to the host

        user = weewx

        # The password for the user name (quotes guard against parsing errors)

        password = weewx

##############################################################################

#   This section configures the internal weewx engine.

[Engine]

    

    [[Services]]

        # This section specifies the services that should be run. They are

        # grouped by type, and the order of services within each group

        # determines the order in which the services will be run.

        prep_services = weewx.engine.StdTimeSynch

        data_services = user.extra_sensors_service.ExtraSensorsService,

        process_services = weewx.engine.StdConvert, weewx.engine.StdCalibrate, weewx.engine.StdQC, weewx.wxservices.StdWXCalculate

        archive_services = weewx.engine.StdArchive

        restful_services = weewx.restx.StdStationRegistry, weewx.restx.StdWunderground, weewx.restx.StdPWSweather, weewx.restx.StdCWOP, weewx.restx.StdWOW, weewx.restx.StdAWEKAS

        report_services = weewx.engine.StdPrint, weewx.engine.StdReport

=============================== extra_sensors_service

import syslog

import weewx

import time

import os

from weewx.wxengine import StdService

#import Adafruit_BMP.BMP085 as BMP085

import Adafruit_DHT

DHT_SENSOR = Adafruit_DHT.DHT22

DHT_PIN = 4

class ExtraSensorsService(StdService):

    def __init__(self, engine, config_dict):

        super(ExtraSensorsService, self).__init__(engine, config_dict)      

        d = config_dict.get('ExtraSensorsService', {})

        # Read from config which pin to use on the RPI GPIO

        # Defaults to 4

        self.DHT22_pin = d.get('DHT22_pin', 4)

        # Use the loop packet event as that allows data to still get into the WeeWX database

        # as well as supporting a OLED module on the RPI

        self.bind(weewx.NEW_LOOP_PACKET, self.load_data)

    

    def load_data(self, event):

        try:

            #self.get_bmp180(event)

            self.get_DHT22(event)

        except Exception, e:

            syslog.syslog(syslog.LOG_ERR, "extrasensors: cannot read value: %s" % e) 

    # Get BMP180 data

    #def get_bmp180(self, event):

    #    sensor = BMP085.BMP085()

    #   pressure = float(sensor.read_pressure()/100.0)

    #    syslog.syslog(syslog.LOG_DEBUG, "extrasensors: found pressure value of %s mbar" % pressure)

        # NOTE: stores as mbar

    #   event.packet['pressure'] = float(pressure)

    # Get DHT22 data

    def get_DHT22(self, event):

        sensor = Adafruit_DHT.DHT22()

        humidity, temperature = DHT.read_retry(DHT.DHT22, self.DHT22_pin)

        if humidity is not None:

            syslog.syslog(syslog.LOG_DEBUG, "extrasensors: found humidity value of %s %%" % humidity)

            event.packet['outHumidity'] = float(humidity)

        if temperature is not None:

            syslog.syslog(syslog.LOG_DEBUG, "extrasensors: found temperature value of %s C" % temperature)

            # NOTE: stores as celsius

            event.packet['outTemp'] = float(temperature)

=================================== Loop data

LOOP:   2020-09-01 17:25:14 CDT (1598999114) altimeter: 26.8909579546, appTemp: -7.515, barometer: 26.9313486, beaufort: 0, cloudbase: None, daily_rain: 0.15, dateTime: 1598999114, day_of_year: 0, dewpoint: None, heatindex: 0.0, humidex: None, inDewpoint: 14.5719060302, inHumidity: 5.0, inTemp: 96.5, maxSolarRad: None, minute_of_day: 0, outHumidity: 0.0, outTemp: 0.0, pressure: 26.4708164393, rain: 0.0, rainRate: 0, rain_total: 0.23, usUnits: 1, wind_average: 0.74564728398, windchill: 0.0, windDir: 268.23516, windSpeed: 0.559235462985

LOOP:   2020-09-01 17:25:15 CDT (1598999115) altimeter: 26.8909579546, appTemp: -7.62, barometer: 26.9313486, beaufort: 0, cloudbase: None, daily_rain: 0.15, dateTime: 1598999115, day_of_year: 0, dewpoint: None, heatindex: 0.0, humidex: None, inDewpoint: 14.5719060302, inHumidity: 5.0, inTemp: 96.5, maxSolarRad: None, minute_of_day: 0, outHumidity: 0.0, outTemp: 0.0, pressure: 26.4708164393, rain: 0.0, rainRate: 0, rain_total: 0.23, usUnits: 1, wind_average: 0.683510010315, windchill: 0.0, windDir: 269.646924, windSpeed: 0.74564728398

REC:    2020-09-01 17:25:00 CDT (1598999100) altimeter: 26.887839304, appTemp: -7.71530405405, barometer: 26.928216027, beaufort: 0.290540540541, cloudbase: None, daily_rain: 0.15, dateTime: 1598999100, day_of_year: 0.0, dewpoint: None, ET: None, heatindex: 0.0, humidex: None, inDewpoint: 14.5042904412, inHumidity: 5.0, inTemp: 96.4027027027, interval: 5, maxSolarRad: None, minute_of_day: 0.0, outHumidity: 0.0, outTemp: 0.0, pressure: 26.467737434, rain: 0.0, rainRate: 0.0, rain_total: 0.23, usUnits: 1, wind_average: 0.877688990518, windchill: 0.0, windDir: 297.618472457, windGust: 2.67190276759, windGustDir: 300.705732, windrun: 0.076237116732, windSpeed: 0.914845400784

LOOP:   2020-09-01 17:25:19 CDT (1598999119) altimeter: 26.8909579546, appTemp: -7.69, barometer: 26.9313486, beaufort: 0, cloudbase: None, daily_rain: 0.15, dateTime: 1598999119, day_of_year: 0, dewpoint: None, heatindex: 0.0, humidex: None, inDewpoint: 14.5719060302, inHumidity: 5.0, inTemp: 96.5, maxSolarRad: None, minute_of_day: 0, outHumidity: 0.0, outTemp: 0.0, pressure: 26.4708164393, rain: 0.0, rainRate: 0, rain_total: 0.23, usUnits: 1, wind_average: 0.74564728398, windchill: 0.0, windDir: 272.470452, windSpeed: 0.86992183131

============================= From DHT22 Sensor CSV file

09/01/20,17:20,39.0*C,29.3%

09/01/20,17:20,39.0*C,29.3%

09/01/20,17:20,39.0*C,29.3%

09/01/20,17:20,39.0*C,29.4%

09/01/20,17:20,39.0*C,29.3%

09/01/20,17:21,39.0*C,29.3%

09/01/20,17:21,39.0*C,29.3%

09/01/20,17:21,39.0*C,29.3%

09/01/20,17:21,39.0*C,29.3%

09/01/20,17:21,39.0*C,29.7%

==========================

Advice with explanations are appreciated.

TIA

Michael

[gjr80]

Hi,

If you already have code that is reading your sensors then it is a simple step to incorporate that code in to a WeeWX service framework and I would suggest that going down the fileparse route is un-needed complexity (plus fileparse is a driver not a service so you would need to recode the fileparse driver to operate as a service). 

In terms of what you have posted, your config file looks fine as does the code in your service. Assuming you have no errors/warnings in the log when running your service (do you?) I would start by looking closely at the working code that produces your csv file and the corresponding code in your service that appears not to work. There will be a difference/error there somewhere. Feel free to post your working code if you wish.

Gary

[Tom Keffer]

I agree with Gary. You can get this to work.

You put in a logging statement to log the values coming off of the DHT22. What does the log say? Are the values zero?

Is there a difference between how you produced the values for the csv file and how you are producing the values in the weewx service? 

There is one thing I still don't understand. The script starts with:

 def get_DHT22(self, event):
        sensor = Adafruit_DHT.DHT22()
        humidity, temperature = DHT.read_retry(DHT.DHT22, self.DHT22_pin)

        ...

What is DHT? It does not appear anywhere in the extra_sensor_service.py file. Adafruit_DHT appears, but not DHT. Are we seeing only part of the file?

-tk

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[Tom Keffer]

Oh, one other thing: the csv file suggests that the values will be in metric units, that is, Celsius for temperature.

However, the LOOP packets have usUnits==1, which means they will be in US units. You will have to do a unit conversion.

-tk

[Michael Grossie]

Below is the code (script) for the DHT22 Temperature/Humidity Sensor to log data in a CSV.

============================

#program to capture  data from the DHT22 Sensor and put into a file

import os
import time

import Adafruit_DHT

DHT_SENSOR = Adafruit_DHT.DHT22
DHT_PIN = 4

try:
   f = open('/home/weewx/archive/humidity.csv', 'a+')
   if os.stat('/home/weewx/archive/humidity.csv').st_size == 0:
           f.write('Date,Time,Temperature,Humidity\r\n')
except:
    pass

while True:
    humidity, temperature = Adafruit_DHT.read_retry(DHT_SENSOR, DHT_PIN)

    if humidity is not None and temperature is not None:
        f.write('{0},{1},{2:0.1f}*C,{3:0.1f}%\r\n'.format(time.strftime('%m/%d/%y'),
time.strftime('%H:%M'), temperature, humidity))
    else:
        print("Failed to retrieve data from humidity sensor")
 
    time.sleep (10)
===================== SYSLOG - Prior to the change in blue in the extra_sensors_service - previously posted

Sep  1 12:05:32 raspberrypi weewxd: extrasensors: cannot read value: global name 'DHT' is not defined
Sep  1 12:05:33 raspberrypi weewxd: extrasensors: cannot read value: global name 'DHT' is not defined
Sep  1 12:05:34 raspberrypi weewxd: extrasensors: cannot read value: global name 'DHT' is not defined
Sep  1 12:05:35 raspberrypi weewxd: extrasensors: cannot read value: global name 'DHT' is not defined
Sep  1 12:05:36 raspberrypi weewxd: extrasensors: cannot read value: global name 'DHT' is not defined

========================SYSLOG - After the change to the extra_sensors_service script - previously posted

Sep  1 18:51:31 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable

Sep  1 18:51:32 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable
Sep  1 18:51:33 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable
Sep  1 18:51:34 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable
Sep  1 18:51:35 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable
Sep  1 18:51:36 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable
Sep  1 18:51:37 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable
Sep  1 18:51:38 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable

================

Guess I will need some help on the converting temperature from celsius to fahrenheit and humidity from mbar to inHg also

TIA 

Michael H Grossie

mhgr...@sbcglobal.net

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[Tom Keffer]

As suspected. Try changing this

def get_DHT22(self, event):
        sensor = Adafruit_DHT.DHT22()
        humidity, temperature = DHT.read_retry(DHT.DHT22, self.DHT22_pin)

        ...

to this

def get_DHT22(self, event):
        sensor = Adafruit_DHT.DHT22()

        humidity, temperature = Adafruit_DHT.read_retry(DHT.DHT22, self.DHT22_pin)

        ...

The problem was the too-broad exception catch, which was catching (and swallowing) the TypeError exception. You should either get rid of the exception clause, or narrow it down to errors you actually expect.

Finally: the error was in the log all along. It's always a good idea to include the actual log, rather than simply summarize it.

-tk

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[Michael Grossie]

Tom;

Made the change that you suggested - Syslog shows:

Sep  2 10:35:47 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable
Sep  2 10:35:48 raspberrypi weewxd: extrasensors: cannot read value: 'int' object is not callable

 

Trying to figure out where it sees "int" because I don't see it.

================================== extra_sensors_service.py

        humidity, temperature = Adafruit_DHT.read_retry(DHT.DHT22, self.DHT22_pin)

        if humidity is not None:
            syslog.syslog(syslog.LOG_DEBUG, "extrasensors: found humidity value of %s %%" % humidity)
            event.packet['outHumidity'] = float(humidity)
        if temperature is not None:
            syslog.syslog(syslog.LOG_DEBUG, "extrasensors: found temperature value of %s C" % temperature)
            # NOTE: stores as celsius
            event.packet['outTemp'] = float(temperature)

========================

Thanks

 

Michael H Grossie

mhgr...@sbcglobal.net

To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/CAPq0zEDfbfUTn8anu%2BYvW74qANe2kT-YHWwpTbsaq_KvDX%2BvEw%40mail.gmail.com.

[Tom Keffer]

If you remove the exception clause, the stack unwinding will show you exactly where the error is.

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[gjr80]

The answer is pretty obvious if you compare the working code with the non-working service. You want:

DHT_SENSOR = Adafruit_DHT.DHT22

not

DHT_SENSOR = Adafruit_DHT.DHT22()

Gary

[Michael Grossie]

Gary,

Made the change you suggested - 

From: DHT_SENSOR = Adafruit_DHT.DHT22()

To: DHT_SENSOR = Adafruit_DHT.DHT22

Now have this from the Syslog -

Sep  2 18:38:37 raspberrypi weewxd: extrasensors: cannot read value: global name 'DHT' is not defined
Sep  2 18:38:38 raspberrypi weewxd: extrasensors: cannot read value: global name 'DHT' is not defined

--------

Tom,

Is this the line you think I should remove from the extra_sensors_service.py -

 except Exception, e:
            syslog.syslog(syslog.LOG_ERR, "extrasensors: cannot read value: %s" % e)

 Michael H Grossie

mhgr...@sbcglobal.net

To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/66685c66-7c21-46d2-b019-b15323487039n%40googlegroups.com.

[Tom Keffer]

Tom,

Is this the line you think I should remove from the extra_sensors_service.py -

 except Exception, e:
            syslog.syslog(syslog.LOG_ERR, "extrasensors: cannot read value: %s" % e) 

Yes (along with its corresponding 'try' statement).

It appears that you also have another "DHT" that is undefined. Removing the exception statement will show you exactly where it is. What you want in its place... I have no idea. Maybe your variable DHT_SENSOR?

Michael, this would go a lot faster if you do a critical review of your code, rather than relying on remote debugging.

-tk

-tk

[Michael Grossie]

Tom, Gary

Got it working. Now just need to remove about 10 digits after the decimal in the outHumidity and convert the temperature from Celsius to Fahrenheit.

Also found that I had to run weewxd as python3 and not python.

The code that is working is below, suggestions on the humidity and temperature issues welcome -

========================extra_sensors_service

# Weewx Service to gather data from Adafruit_DHT. DHT22 Sensor  RUN AS python3

import syslog
import weewx
import time
import os
from weewx.wxengine import StdService

import Adafruit_DHT as DHT

DHT_SENSOR = Adafruit_DHT.DHT22

DHT_PIN = 4
DHT22_PIN = 4

class ExtraSensorsService(StdService):
    def __init__(self, engine, config_dict):
        super(ExtraSensorsService, self).__init__(engine, config_dict)      
        d = config_dict.get('ExtraSensorsService', {})
        # Read from config which pin to use on the RPI GPIO
        # Defaults to 4

        self.DHT22_PIN = d.get('DHT22_PIN', 4)

        # Use the loop packet event as that allows data to still get into the WeeWX database
        # as well as supporting a OLED module on the RPI
        self.bind(weewx.NEW_LOOP_PACKET, self.load_data)
   
    def load_data(self, event):

#       try:
#            self.get_bmp180(event)
            self.get_dht22(event)
#       except Exception, e:
#            syslog.syslog(syslog.LOG_ERR, "extrasensors: cannot read value: %s" % e)

    # Get DHT22 data
    def get_DHT22(self, event):

        humidity, temperature = DHT.read_retry(DHT.DHT22, self.DHT22_PIN)

        if humidity is not None:
            syslog.syslog(syslog.LOG_DEBUG, "extrasensors: found humidity value of %s %%" % humidity)

            event.packet['inHumidity'] = float(humidity)

        if temperature is not None:
            syslog.syslog(syslog.LOG_DEBUG, "extrasensors: found temperature value of %s C" % temperature)
            # NOTE: stores as celsius

            event.packet['inTemp'] = float(temperature)

========================

 

Michael H Grossie

mhgr...@sbcglobal.net

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