There was a long delay with no update about my projects. The reason for this is, I focused on other non electronic related projects. I promised to publish all files and information about the plant watering sensor project in August, and here are all the files.
First some Important Notes
Even with these files, it is a very advanced project to do. To produce the PCB, you need a board house which is used to precise and high quality PCBs, like Eurocircuits. Also all pads are prepared to reflow soldering, and not hand soldering. It may be possible to solder the resistors in place using a regular solder iron, but it will be hard to do.
Programming the very small MCU is another difficult task. You will need the correct development environment Atmel Studio from Microchip to do so. You also need a programmer, like the Atmel-ICE and a special socket where you can temporarily connect and power the chip for programming. Because of the design and default configuration of the chip, you have to pre-program the chip and activate the wireDEBUG protocol.
At last, the foot part needs to have an environmental sealing. Otherwise, the regular solder mask of the boards will quickly wear off, and the copper of the traces may kill your plants.
You have to be experienced in producing microcontroller based hardware designs using SMD components and a reflow process. You also need to be skilled with programming tools and devices.
The documentation of the hardware is licensed under the CERN OHL v1.2 or later. You can find all details about the license here. The GIT repository contains a copy of the license.
All files are in this GIT repository:
I will add more details later, but these are the raw files with all information you need to produce your own sensor.
If you have questions, miss some information or just have any feedback, feel free to add a comment below.