After 5 months I was able to continue with the motorized kayak…Since the beginning of testing in the field, a major bottleneck was the transport of the kayak from my home to the riverside. Finally, I made a simple transporting system (recycling the wheels of my son’s bike; I had to promise him he will get a new, bigger bike soon!) in order to be able to walk to the shore (+/- 1.5 km).
Following images show the final set-up of the kayak: 2 motors on the back and a sonar on the front. I am using an Arduino MEGA with Adafruit GPS and external antenna, while the data (X, Y and Depth) is saved on an Adafruit Feather M0 SD .
The BR ping sonar is working well now and I was able to do some depth measurements near the shore. Following images show the measurements taken and a simple bathymetric map made by interpolation.
First it was rather surprising that the depth already reached to 4-5m rather closely to the shore. This is explained (and confirmed by the locals) by the fact that in the past sand has been abstracted for filling up the nearby beach of the local club. Hence, it is not representative for the shore of the Paraguay River.
With these results, the objectives for the first prototype were reached (understanding the electronics and making a first measurement). Now the second stage of the project is starting that should result in a more robust/compact platform to be tested in another setting(remote farms in the countryside). I will write a second post with the new objectives/expectations/plans (your advice and constructive critics would definitely be welcomed at this stage!)