Developer Project (Temperature Monitor)

Hi everyone,

I’m a .NET Developer and new to the world of Velleman Projects.

I want to create a controller which can send temperature data, and in the future other values like humidity, etc…, to my computer, which I can manage in c#.
Ideally I’d like this to happen wirelessly, through Wifi or radio(for which I would need a receiver on my pc), but maybe it’s easier (and cheaper) to start with a basic model which I connect to my pc directly.

First of all can any one tell me if this is possible, if so which components can I use?

Thanks in advance!
Kind regards,
Tobias

You might want to take a look at K8055/VM110N/K8061
These are USB input/output cards with digital and analog input/outputs.

[quote=“VEL417”]You might want to take a look at K8055/VM110N/K8061
These are USB input/output cards with digital and analog input/outputs.[/quote]

And which sensor could I use?

For temperature you might want to look at the K8067 (link below)
http://www.vellemanusa.com/products/view/?id=521726

There is also a demo software package for the k8055
http://www.vellemanusa.com/support/downloads/?code=K8067

There are several threads on this forum about temperature measurement with a K8055. Like this one: viewtopic.php?f=3&t=8041

I posted a complete circuit with pictures at the end of that thread: viewtopic.php?f=3&t=8041&start=15#p33909

Humidity is another animal. The sensors often are variable capacitors, and that cannot easily be measured with a stock K8055/K8055N. I do have a Humirel HS1101 laying around, but didn’t find the time yet to build test circuits with it. My first idea was to build a 555 timer based oscillator where the frequency is controlled by the HS1101. The Open8055 firmware, that I’m also developing, can count frequencies up to 3kHz or so. But it could turn out that the capacity of that sensor is far too low to get any accurate results out of that setup. One would normally use two inputs from RA0 through RA5 of the PIC18F2550 (or similar) in “comparator” configuration to measure the capacitor charge time and deduce the capacitance from that. This would require some modification to the board as well as additional functionality in the Open8055 firmware. But it can definitely be done. It might be possible to use an external comparator circuit and just measure the time in the PIC. Unfortunately, the interrupt supporting ports of the PIC18F2550 are used as digital outputs on the K8055(N) boards. So this still needs board and firmware modifications.

Next up are pressure, wind speed and direction. The first is again rather simple since reading a pressure sensor is more or less ADC. The other two get trickier again as they amount to decoding rotary sensor data, which is also something that should be done inside the PIC firmware because USB or network latencies could have devastating effects on the results.