The "universal wireless testing platform", which previously existed only in 3d renders, has been built. I assembled two transmitters, (as you may notice - I used different connector designs, the white one is slightly better) - and I have been using both of them in the field extensively. I am preparing a video in which I use this system connected to a couple of pressure sensors and a Parker flow meter to adjust an open center LS system. This video is not so much about the wireless flow and pressure measurement, as it is about the fact that that particular unit is the perfect example of an open-loop LS pump with stand-by pressure significantly higher than the actual delta P - but still, the wireless measurement coupled to the App that shows 3 channels and the delta P is an invaluable helper.
A few notes now. Although the current connector design allows me to instantly swap my attachments - after using it for a while I think that some changes must be made. First - the magnets, although very strong, must be still stronger. It takes about 4-5kg of force to separate an attachment and I thought it would be plenty - but "ruff industrial conditions" dictate otherwise. The next "hot-swappable" design will have the connector pointing downward, too.
The spring-loaded pogo pin connector, on the other hand, turned out to be a complete success. I'm definitely using this design solution in other projects. Also, initially, I was striving to make the device as compact as possible, however, after using it for a while I came to the conclusion that its size doesn't matter that much. Every time I use the transmitter, I connect it to a pressure point, slap it on the nearest metallic something - and forget about it.
At this point, I am confident that in current state the basic functionality is there (both hardware and software-wise), and although I am doing further development (like temperature sensor integration, which will allow not only precise temperature measurement but also programmable temperature compensation if necessary) - I believe that it is time to begin thinking about a minimum viable product, which, I believe, will be a simple system that can be connected to one or two sensors with standard interfaces - not more not less. A lot of people I talked to actually didn't care that much about the extended functionality or "fast switching" between sensors or attachments, but rather wanted a "turnkey" solution like "press a button - get a pressure reading". So - that's what I'll concentrate on.
Also - securing sensors by their electric connectors seems a little weak to me. It is very convenient, but I am carrying my precious transmitters like babies - and most people definitely won't, so I am envisioning something like a closed box with a 1/4'' BSP steel port to the outside with the sensor securely mounted and stored inside the enclosure.
The "universal wireless platform" that I am using now is still a great development tool, so I'll keep using it for that purpose.
Here's one of my latest tests. You can see a wireless transmitter connected to a Parker SCFT-600-02-02 flow meter (these are just great for this system because these flow sensors have an analogical 0...3V output) - which I am using to verify the function of a Hydac SRVR-12 flow control valve with built-in pressure compensator.
That's it for now - stay tuned for the MVP news!