This project is a first implementation of an environement meter that can be used to monitor soil based plants.

The hardware is based on espressif's[1] wonderful ESP32[2] and we use the development board from DOIT[3] (DOIT ESP32 DEVKIT V1).

The current setup consists of just the following sensors

• DHT22 - humidity and temperature sensor
• TSL2561 - to measure the light exposure
• some capacitive soil moisture meter
• some float switch to measure the water level and actuators
• a pump

As my toolchain with the ESP IDF stopped working at a certain point. I tried out the Arduino IDE which immediately just did work. As I am not very happy with this solution, I will try again with the ESP IDF later, but for now we recommend using this solution:

• Install the Arduino IDE
• Add the board
  • Go to: "Tools", "Board"
  • Choose:
    • "DOIT ESP32 DEVKIT V1"
• Add the libraries
• Go to: "Sketch", "Include Library", "Manage Libraries"
• Choose: * "Adafruit Unified Sensor" * "DHT sensor library" * "ESP32" * "ESP32 BLE Arduino" * "Adafruit TSL2591" (or TSL2561 resp.)

The development is in the subfolder calles arduino-ide, just open the main .ino file in your IDE.

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

To setup a working environment, you need the IDF[4] (documentation for the IDF[5]) and the toolchain[6] (documentation for the crosstoolchain[7]) - and obviously, the ESP32 hardware itself. The setup of those components is very nicely documented and quite straightforward (nice work guys!).

As we use libraries from the arduino[8] project, you have to first add the arduino-esp32[9] sources and then add those libraries all as components to a special subdirectory as follows. These are the third party libraries from Adafruit[10] (kudos guys!):

• Unified Sensor Library[11] (e.g. latest stable)
• DHT Sensor Library[12] (e.g. latest stable)

Create a directory called components on top of the projects dir for the components (see [13]) to be put in - you may also just softlink to the library sources...

The detailed instructions for the arduino-esp32 can be found under [14].

The Adafruit[9] libraries can be cloned to the same folder too. Afterwards just create an empty file in the top folder called component.mk and create a directory called include where you link all the header files you need into (*.h) as the esp-idf will search them there.

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 values recieved from the sensors - e.g. while for light there are standardized units that we will probably use (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.

[1] https://www.espressif.com/
[2] https://docs.espressif.com/projects/esp-idf/en/latest/hw-reference/index.html
[3] https://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] https://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