README.md

Additions by pervasive computing workgroup

Time Tracking

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Documentation

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CO₂ Ampel

CO₂ Ampel is an open-source project, written in C++ for ESP8266 or ESP32.

It measures the current CO₂ concentration (in ppm), and displays it on an LED ring.

The room should be ventilated as soon as one LED turns red.

Features

The CO₂ Ampel can:

• Display CO₂ concentration on LED ring.
• Allow calibration.
• Get current time over NTP
• Send data over MQTT.
• Send data over LoRaWAN.
• Display measurements and configuration on a small website.
• Allow configuration of every parameter via web-interface.
• Log data to a CSV file, directly on the ESP flash memory.
• Accept many interactive commands.

Hardware Requirements

• ESP8266 or ESP32 microcontroller (this project has been tested with ESP8266 ESP-12 WIFI and TTGO ESP32 SX1276 LoRa)
• Sensirion SCD30 "Sensor Module for HVAC and Indoor Air Quality Applications"
• NeoPixel Ring - 12, or NeoPixel Ring - 16 (experimental)

See the documentation for more info.

Software Requirements

• PlatformIO or
• Arduino IDE

Installation

• If config.h does not exist, copy it from config.public.h
• You can modify config.h, e.g. for measurement time-steps, WiFi access, MQTT, NTP and web-server.
• Every parameter can be modified later, via the web-interface.

PlatformIO

PlatformIO can be run from VSCODE, Eclipse CDT or console:

make upload board=esp8266 && make monitor # For ESP8266

make upload board=esp32 && make monitor # For ESP32

Arduino IDE

• All the libraries are included in this repository. No need to install anything via Library Manager.

• Add your board to the board manager. Either ESP8266:

    http://arduino.esp8266.com/stable/package_esp8266com_index.json

  or ESP32:

    https://dl.espressif.com/dl/package_esp32_index.json

• Choose the correct board in Tools > Board > ...

• Choose the correct Flash size (e.g. "Flash Size : 4MB (1MB FS, OTA:~1019kB)" for ESP8266 ESP-12 WIFI)

• Verify

• Upload

• Tools > Serial Monitor

Usage and configuration

• Start the Ampel
• If you didn't define wifi SSID and Passwords in config.h
  • The Ampel should blink turquoise, to indicate Access Point mode.
  • Connect with a laptop/smartphone to ESPxxxxxx WiFi.
  • Open a browser, it should bring you to the Ampel web-page.
  • The Ampel web-page will be shown. You can click on "Configuration".
  • You'll have to set an Ampel password with at least 8 characters.
  • You can set WiFi SSID + Password if you want. It will then try to connect if you disconnect from the Access Point.
  • If you don't specify SSID + Password, the Ampel will simply stay in Access Point mode.
  • The Ampel password will be required if a connection fails, and the Access Point starts again.
  • The Ampel password will be needed (with user 'admin') to connect to the config web-page once the Ampel is connected to WiFi.
• Once you defined Wifi SSID, Ampel password and WiFi password:
  • the Ampel will try to connect, displaying a rainbow wheel.
  • if the connection is successful, LEDs will be green.
  • if the connection fails, LEDs will be red, and the Ampel will return back to Access Point mode.
• It might be necessary to reset the Ampel after changing important parameters.
• You can rename the Ampel. This name will be used instead of ESPxxxxxx for CSV files and the mDNS address. You'll get a new CSV file after renaming, which can be convenient, e.g. to indicate at which location the measurements were made.
• If you forgot the password, you can send reset_config as command, and reset the ampel.
• If you disabled WiFi, you can enable it again with wifi 1.
• It's also possible to specify WiFi SSID and password in the console, with ssid wifi_ssid_here and pwd wifi_password_here commands.
• You can enable CSV by clicking on "+CSV", or disable it by clicking on "Disable CSV".
• The same applies to MQTT and LoRaWAN.
• If you disable a set, the parameters are still saved, and will appear again once the service is enabled.

Available commands

In Arduino IDE Serial Monitor or PlatformIO Monitor, type help + Enter in order to list the available commands:

• ap 0/1 (Disables/enables access point).
• auto_calibrate 0/1 (Disables/enables autocalibration).
• calibrate 600 (Starts calibration process, to given ppm).
• calibrate (Starts calibration process).
• calibrate! 600 (Calibrates right now, to given ppm).
• co2 1500 (Sets CO₂ level, for debugging).
• color 0xFF0015 (Shows color, specified as RGB, for debugging).
• csv 60 (Sets CSV writing interval, in s).
• format_filesystem (Deletes the whole filesystem).
• free (Displays available heap space).
• led 0/1 (Turns LEDs on/off).
• local_ip (Displays local IP and current SSID).
• lora 300 (Sets LoRaWAN sending interval, in s).
• mqtt 60 (Sets MQTT sending interval, in s).
• pwd abc (Sets WiFi password to 'abc').
• reset (Restarts the ESP).
• reset_config (Resets the complete IotWeb config).
• reset_scd (Resets SCD30).
• save_config (Saves the config to EEPROM).
• send_local_ip (Sends local IP and SSID via MQTT. Can be useful to find sensor).
• set_time 1618829570 (Sets time to the given UNIX time).
• show_csv (Displays the complete CSV file on Serial).
• ssid name (Sets SSID to 'name').
• timer 30 (Sets measurement interval, in s).
• wifi 0/1 (Turns Wifi on/off).
• wifi_scan (Scans available WiFi networks).

The commands can be sent via the Serial interface, from the webpage or via MQTT.

Authors

• Eric Duminil (HfT Stuttgart)
• Robert Otto (HfT Stuttgart)
• Myriam Guedey (HfT Stuttgart)
• Tobias Gabriel Erhart (HfT Stuttgart)
• Jonas Stave (HfT Stuttgart)
• Michael Käppler

Contributing

• Merge requests are welcome, and should be based on the develop branch.
• The develop branch gets merged into the master once it has been sufficiently tested.
• For major changes, please open an issue first to discuss what you would like to change.

License

Copyright © 2022, HfT Stuttgart GPLv3

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