I think you would need to consult a civil engineering design firm for this one.
The reason you don't see this widely implemented already is because of its cost. You're not going to get away with using simple microcontrollers and pressure sensors.
The loads you need to deal with are far greater. What's the heaviest weight of a single axle of the heaviest vehicle your parking lot will accommodate? In the U.S., a 1-ton pickup (a 6,000lb vehicle) can put well over 3,000lbs on the front axle alone, and therefore that much weight on the sensor under the pavement in the parking spot.
The cost of one of those load cells is about $200+ in the U.S.
You'd also need to have considerations for motorcycles (can be less than 400lbs) and how people park them in a park spot, possibly missing your load cell altogether.
Then there's the cost of installation of a single load cell in a single parking spot.
Total up what it takes to install them, per parking spot, and you've got an enormous cost. Compare that to the expected cost savings to the business for telling people what spots are open. Oh! That's right! The owner of the parking spot didn't buy the gas for the customers! So, that savings for the owner of the parking spot is ZERO!
That's why you don't see this being widely used anywhere.
I agree with Mycroft that the best solution is probably an image processing solution.
You could start with the Aforge library and make use of IP webcams.
Or checkout my Opensource webcam movement detection system [^]that is IP webcam enabled which makes use of Aforge.
(Warning the code is an example of how not to write .Net code however it was written around 5 years ago and I have learned a lot since...)
“That which can be asserted without evidence, can be dismissed without evidence.”
I'm trying to create a C sharp application that can run under elevated credentials and give full mailbox access or remove full mailbox access for groups.
I cannot get system.management.automation to work in Visual Studio as a reference, so most likely any solution involving that is out of the question. It displays a yellow triangle and exclamation point when I add it as a reference.
I have a c sharp dll that I can call a function within it, pass values and have it perform a task.
I would like to do this through a webpage by having a user fill out a few form boxes, press the submit button and have the button call the dll that is on the webserver and pass the values from the input boxes on the webpage, so the dll can then do its function.
I'd like to be able to write back to the webpage any success or failure messages as well.
The button doesn't call the DLL on the server. Supposing your web application is written in ASP.NET, you bind to the Submit Click event and in the code behind the web page, you create an instance of the class that you are interested in, and pass in the values. What happens next really depends on whether or not the operation is quick - if it is, simply return the value. If not, you would have to spin this off as an asynchronous operation and put logic in place to periodically check the values.