Hi guys,

There are some progress on many fronts.

I met with a potential partner company that could connect me with a University research group to dive a little bit deeper into the bio-electromagnetic phenomena we would like to process and show with our device. The goal would be to get a few papers published so that investors can see this development less risky. (If you are not familiar with bio-electromagnetics, please check out my blog at http://blog.biobalancedetector.com/)

I also met with a researcher friend of mine who works on some fascinating stuff and we decided to work together on a side-project which eventually could lead to a radically new sensor design. I can't tell too much about it just yet, there is a long list of experiments we have to build and document first.

On the architecture side I'm investigating some new platforms and ICs.

As you probably know the new Raspberry Pi 4 model B is available. It's not a critical update for me at the moment at all, and there are many things missing on the software side, but still, one thing already made it attractive: it might finally work with my Analog Discovery 2 using its USB3 port. (The USB2 ports are still unusable due to a Linux driver fault. More details here: https://forum.digilentinc.com/topic/1713-analog-discovery-2-vs-raspberry-pi-3/)

My original choice for the ADC was the AD7616 which is still a fantastic little IC, but I realized that to build an evaluation board for it would cost me too much (of my time and money), so I started to look for a similar one that is more popular.

AD7606 is fairly well known, it has somewhat similar specs and there are C++ and Python sources available for Raspberry Pi. Extra good news that Analog Devices came out with an improved version just a few weeks ago, called AD7606B, and its spec is pretty close to our requirements. It's also backward pin compatible with the AD7606, so upgrade should be a no-brainer.

Anyway, I ordered two types of evaluation boards of the AD7606 from AliExpress and I got them a few days ago. I started to play around with the Python module and test scripts I found, and although it looks a little buggy, it's good for now.

I also have my eyes on the DACC2plate (https://pi-plates.com/daqc2r1/) mainly because it's a complete Raspberry Pi HAT and it has C# library which I could probably use out of the box with .NET Core.

I run a few tests to see how much of a difference can I measure in the impedance of tap water, filtered water and salted water. It's pretty significant, so they will came useful in the future.

I will continue my experiments with the impedance measurements of different fluids which hopefully will lead me closed to the new sensor design. We'll see!

Andras