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This is a write up, containing instructions, demos, experiments and lessons learned, on the AutoSQA project I developed for the NXP Hovergames3. The AutoSQA project, which can be seen as a system, is an autonomous platform for sampling soils in agricultural fields. It uses the NXP MR-Buggy3 as the robotics platform with add sensors to accomplish this task. The autonomous part is handled by the NXP NavQPlus with ROS 2 nodes. The NXP MR-Buggy3 Kit, together with the new NXP NavQPlus and the BOSCH BME688 where part of awarded hardware (discounts) from NXP, as part of the NXP HoverGames3, to accomplish this project.

Soil Monitoring: Importance, what and how
Agriculture all over the world is facing a difficult and critical challenge with degradation of soil fertility and with that lower crop yields, even with higher fertilization. Soil fertility is decreasing due to a variety of factors: increase in soil salinity, shift of pH levels, topsoil erosion, etc. This is happening in part due to climate change and due to overfertilization, use of high mineral content water for irrigation and just overuse of soils. To prevent loss of fertility, as well as to recover fertility, it is crucial to monitor the soil so that adequate actions can be taken.

(As a small side note here, I played around with ChatGPT to look into soil monitoring, relevant properties and used sensors and it almost always highlighted at the end of each answer the importance of monitoring soils properties.)

This project aims to aid in the soil monitoring step, by developing an inexpensive and autonomous rover that can scan the soil with a sensor platform that can identify different relevant properties like pH, VOCs content, humidity, salinity and porosity/”stiffness”. By keeping the monitoring solution inexpensive, in relation to normal agriculture probing solutions, and autonomous, it will allow for more farmers, especially small farms and farmers in developing nations, to adequately monitor their soils and prevent, or even mend, soil fertility degradation.

Project Overview/Outline
The AutoSQA system can be separated into four different parts, which together form the whole AutoSQA system:
- The robotics platform: The robotics platform is the physical platform of the AutoSQA system, where all the sensors are mounted to and allows them to be moved around. The basis for this is the Mobile Robotics Buggy3 (MR-Buggy3) kit from NXP, which itself uses the WLToys 124019 RC car chassis as the basis. It adds two plates (PCBs) on top as a support structure for fixing diverse sensors and controllers, like the RDDRONE-FMUK66, which is the controller of the MR-Buggy3 and runs the PX4 autopilot.
- The sensor platform: The sensor platform is a couple of sensors, together with their signal conditioning and conversion, and actuators used to sample the soil/fields. Two types of sensors are used: Direct contact sensors (in contact with the soil), and indirect contact sensors (like air sensors).
- The brains: The brains, the onboard computer, is what controls the whole autonomous acquisition platform. It gathers the sensor data and packets them, and enables the Buggy to traverse the field safely and on a defined trajectory. The onboard computer used is the NavQPlus from NXP.
- The GUI: This is the part interfacing with a user, allowing to set up missions, monitor progress and errors and display the acquired data.

Over the next sections I will go in more detail, explaining how each of these parts work, how they where developed and how they can be replicated. This is then followed by a section with the performed experiments (and the results) and a section with some demo videos as well as a section with my plans for future work.”

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