inst

Station client

Scripts to read one or multiple sensors connected to the I2C bus on a Raspberry Pi and submit them to the station-monitoring-service.

Prerequisites

Before you can install and connect the sensors, make sure of the following:

• Optional: copy your public SSH key to your Pi for Passwordless SSH access
• I2C must be enabled. See Enabling I2C
• The station-monitoring-service is running. See running the Station Monitoring Service
• The station exists in the service and contains the sensors that you plan to connect to it.

Installation

Learn how to connect the sensor and install the Station Client.

1. Login to your Pi via SSH

2. Create virtual env

   The virtual env will contain all the software needed to run the station-client in a nicely isolated and dedicated environment, so it won't interfere with anything else on the system.

   cd ~
   mkdir rcm && cd rcm
   python3 -m venv venv
   source venv/bin/activate
   

   (1): Optional: Navigate to the home folder, just in case you were in another directory unintentionally.

   (2): Creates the directory rcm and navigate into it. This will be the folder containing everything related to the Residential Climate Monitoring project.

   (3): Create a virtual env with the name venv. All the necessary python package will end up here.

   (4): Activate the virtual env.

3. Install Station Client

   To install the package:

   pip3 install rcm-station-client
   

   Alternatively, you can also directly clone it if you have a fork or want to make customizations:

   git clone https://gitlab.com/residential-climate-monitoring/station-client.git
   cd station-client
   pip3 install -r requirements.txt
   

Configuration

The Station Client requires some configuration settings before it will work.

• Create .env file

  All the configuration will be read from a .env file. Create it in the root of the "rcm" folder you created during installation. After this step your directory structure should look like this:

  rcm/
  - .env
  - venv/
  

  Note: if you cloned the repo, you must edit the .env file of the project: "rcm/station-client/.env" directly.

• Configure station settings

  Copy and paste the following into the file:

  station-name=test
  api-base-url=https://raspberrypi.local:8080
  

  station-name - Configure the name of the station, typically the location where it is located. E.g. 'living-room'. This must match with the name of the station as it is registered in the Station Monitoring Service.

  api-base-url - This is the location where the station monitoring service API is available on. Change "raspberry" to the hostname and/or change "raspberry.local" to the IP address of the raspberry that runs the Station Monitoring Service to match your environment. The port and http scheme can and should also be changed accordingly to match your environment.

• Configure security settings

  Security is enabled by default on both the client and server side. You can create a free account on Auth0 to obtain the necessary settings, or disable security. If you have an Auth0 account you will need your application client id, client secret, audience and tenant + zone.

  To disable security, add the following:

  auth-enabled=false
  

  Note: Below settings only apply when auth-enabled=true!

  To configure with Auth0, add the following:

  auth-client-id=
  auth-client-secret=
  auth-audience=
  auth-token-endpoint=https://${auth0-tenant}.${auth0-region}.auth0.com/oauth/token    
  

  auth-client-id - In Auth0 you'll have to create an application, which will represent the Residential Climate Monitoring system. Put the client-id here.

  auth-client-secret - This is the secret, make sure this token is safe and access to the file and system is limited to "authorized personnel" only!

  auth-audience - This is the identifier of the API, that you created as part of your Auth0 application. This should match with the station monitoring service.

  auth-token-endpoint - This is the endpoint that will be called by the Station Client to obtain an M2M token. Replace it with your tenant and region.

  Note: You may need to change the Token Expiration in Auth0 because the token endpoint has a quota of 1.000 requests / month. If you intend to run the client regularly (see usage section) then you will quickly exceed this quota, especially if you have multiple stations running. The Station Client caches the token by writing it to a file along with the timestamp when it will expire and request a new one only when it is expired. Setting the Token Expiration to 86400 seconds (24 hours) will allow you to connect up to 32 stations before hitting the quota.

• Configure for testing/development on a machine without I2C

  To disable the I2C altogether and avoid exceptions when running the client on systems without a I2C bus, configure the following:

  disable-i2c=true
  

  Note: sensors that depend on I2C are not supported while I2C is disabled.

Sensor specific configuration

Some sensors allow for customization. Below you can find more details for each sensor.

• BME680

  The sensor can be calibrated with sea level pressure to calculate the current altitude. This is not implemented yet, stay tuned.

• SHT31-D

  The SHT31-D has two modes: Single and Periodic. Currently, it only supports Single (default) mode.

  The sensor also comes with a heater than can be turned on to evaporate any condensation. The heater can only be used when relative humidity is 80% or higher. To turn it on, add the following sensor settings:

  {
    "heater_enabled": true,
    "heat_seconds": 30
  }
  

  To use the secondary address, add the following to the sensor settings:

  {
    "secondary_address": "true"
  }
  

• TSL2591

  The TSL2591 has configurable gain and integration time for various lighting conditions. Learn more about Gain and timing. See the TSL2591 reference sheet for an overview of values you can expect in different conditions.

  Apply the following sensor settings to adjust gain and/or integration time:

  {
    "gain": "GAIN_MEDIUM",
    "integration_time": "100ms"
  }
  

  gain - Sets the gain level, the higher the level the more the signal will be "amplified". Low light conditions requires more gain to be measurable.

  Supported values are:

  • GAIN_LOW - Sets the gain to 1x (bright light)
  • GAIN_MEDIUM - Sets the gain to 25x (general purpose) - default
  • GAIN_HIGH - Sets the gain to 428x (low light)
  • GAIN_MAX - Sets the gain to 9876x (extremely low light)

  integration-time - Set the integration time, a higher value allows the sensor to "capture" more light.

  Supported values are:

  • 100ms - 100 milliseconds - default
  • 200ms - 200 milliseconds
  • 300ms - 300 milliseconds
  • 400ms - 400 milliseconds
  • 500ms - 500 milliseconds
  • 600ms - 600 milliseconds

• SGP30

  The SGP30 requires a baseline for calibration before it can be used. You can configure the location where the file is stored:

    sgp30-baseline-file=/home/pi/rcm-sgp30-baseline.txt
  

Hardware installation

After the software is installed and configured, it is time to connect the sensor(s):

Note 1: On the BME680 this pin is called "SDI" instead.
Note 2: On the BME680 this pin is called "SCK" instead.

Addresses

The I2C addresses are listed below:

Note: To use the secondary address, see sensor specific configuration.

Calibration

This section describes how to calibrate sensors.

• SGP30

  The SGP30 requires a baseline when first used or when off for more than a week. It will automatically establish a new baseline when required and write it to disk.

  Note: this process takes 12 hours to complete.

  Note: each sensor has a unique baseline so baseline values are not transferable between sensors!

Usage

Once, manually

To run the station client manually, run:

python3 station_client.py

Periodically

To run the station client periodically, configure it using Crontab:

To edit crontab settings:

crontab -e

Now add one of the following lines at the bottom:

When installed via pypi in a venv:

* * * * * /home/pi/rcm/venv/bin/python3 /home/pi/rcm/venv/bin/rcm-station-client

When cloned from git:

* * * * * /home/pi/rcm/venv/bin/python3 /home/pi/rcm/station-client/rcm/station_client.py

Note: you may need to change the path to the virtualenv according to your setup.

The * * * * * expression executes the script once every minute. The 0 0 * * * expression executes the script once a day at midnight.

# * * * * *  command to execute
# ┬ ┬ ┬ ┬ ┬
# │ │ │ │ └─ day of week (0 - 7) (0 to 6 are Sunday to Saturday, or use names; 7 is Sunday, the same as 0)
# │ │ │ └─ month (1 - 12)
# │ │ └─ day of month (1 - 31)
# │ └─ hour (0 - 23)
# └─ min (0 - 59)

Troubleshooting

To troubleshoot, the logs can be found at: /home/pi/rcm-station-client.log

License

The Station Client is distributed under the MIT License