lifebase-plant-basic-esp32

Overview

This project is a skeleton implementation of an environment meter that can be used to monitor (and adapt) the surrounding of living systems.

The hardware is based on espressif's1 wonderful ESP322 and we use the development board from DOIT3 (DOIT ESP32 DEVKIT V1).

The current standard setup consists of just the following sensors

• DHT22 - humidity10 and temperature sensor
• TSL2591/TSL256110 - to measure the light exposure
• some capacitive soil moisture meter
• some float switch to measure the water level and actuators
• a pump

Installation

Arduino IDE

As my toolchain with the ESP IDF4 stopped working at a certain point, I reimplemented it for the Arduino8 IDE just to see whether it would work there, and it immediately just did. Over the last year I was asked to do workshops with children on that basis and as it is probably easier to start such a thing with Arduino (and last but not least there is the arduino-cli15), I think we'll just stay with this solution:

• Install the Arduino IDE
• Add the board
  • Add an additional boards manager
    • From "Files" choose "Preferences"
    • Under "Additional Boards Manager URLs" enter URL: https://dl.espressif.com/dl/package_esp32_index.json
  • Now go to: "Tools", "Board"
  • From "Boards Manager" choose "ESP32 Arduino"
  • Exit this level and then choose the following from the resp. menu:
    • Board: "ESP32 Dev Module"
      • Partition Scheme: "Minimal SPIFFS" (otherwise the sketch is too big)
    • (do not use "DOIT ESP32 DEVKIT V1" as there are no options available here)
• Add the libraries
  • Go to: "Sketch", "Include Library", "Manage Libraries"
  • Choose:
    • "Adafruit Unified Sensor"11
    • "DHT sensor library"12
    • "ESP32 BLE Arduino"9
    • "Adafruit TSL2591" (or TSL2561 resp.)

The development itself is done in the subfolder called arduino-ide, just open the main .ino file in your IDE - or in your favorite editor.

To upload/run the code there are some further steps needed, please see the section 'Running the Code' below.

ESP IDF

Warning This section (ESP IDF4 is currently not working. See the Arduino IDE section above..

Running the Code

Prior to using the code on your ESP32, you will have to individualize the installation. There are a few things that you will have to define for the project to be usable, this is first and foremost the individual UUID per device, but also which services should be enabled/disabled and how they will be propagated later. You can easily identify all the places in the code by searching their placeholders double wrapped in braces (curly brackets), e.g. something like: '{{ FOO_BAR }}'.

We have created a custom (bash) shell script for this purpose. This is a quick and dirty solution which will have to be replaced in the future, but for the moment it is quite handy for us. If you do not have access to a bash, you will have to change the values manually/semi-manually. This is how to use the script.

Change to the top folder of your project, where you will find both files, the script create_config.sh and an empty config lifebase_meter-.conf.stub. You can execute the script to get some idea with the help option:

$ ./create_config.sh --help

For a standard installation with a random UUID one could run this:

$ ./create_config.sh Foobar

This command would then create a customized installation and a configfile for future builds under the folder build as follows:

$ ls build/
lifebase_meter-Foobar

The resulting arduino project lifebase_meter-Foobar.ino can then be loaded from within the Arduino IDE and flashed onto the ESP32 as usual.

Bugs

Any bug report or feature request is warmly welcome via the issue tracker here.

At the moment we have not quite decided yet how to handle all the value's units recieved from the sensors - e.g. while for light it is easy (i.e. Lux), we have absolutely no idea how to handle soil moisture. As a pragmatic approach we will just use percentage for everything as a first approach and then later replace it with the definite unit. Let's say, if the BLE unit characteristic is not set, it is assumed to be a temporarily percentage value.

Another problem poses the interpretation of the values. E.g. with different soil types we have a different behavior of moisture -- or with different lifeforms, we have different interpretations for the light conditions. The plants do not care too much about Lux, and their needs also differ between species and life phases.

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1. https://www.espressif.com/
2. https://docs.espressif.com/projects/esp-idf/en/latest/hw-reference/index.html
3. http://doit.am
4. https://github.com/espressif/esp-idf.git
5. https://docs.espressif.com/projects/esp-idf/en/latest/
6. https://github.com/espressif/crosstool-NG.git
7. https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html#setup-toolchain
8. https://www.arduino.cc/
9. https://github.com/espressif/arduino-esp32.git
10. http://adafruit.com/
11. https://github.com/adafruit/Adafruit_Sensor
12. https://github.com/adafruit/DHT-sensor-library
13. https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/build-system.html
14. https://github.com/espressif/arduino-esp32/blob/master/docs/esp-idf_component.md
15. https://arduino.github.io/arduino-cli/<\a>