Phidgets Temperature Sensor

Projects General Guidance
1

Hi, this is my first post here. I'm new to the concept of Arduinos; I have limited programming experience and even less electronics knowledge!

I have an Arduino Duemilanove, which I have connected a pressure sensor to. There's limited resolution, with only a 10 bit ADC on board, I can only achieve a reading to the nearest 0.25kPa and it seems a little "jumpy". I'm looking at improving on this, but I'm very happy with how it's working. I love the fact that it's serial output, making it very easy to interface with Matlab.

I also need temperature readings in the range -100C to +200C. For this I have a Phidgets 4 input temperature sensor, which can do the required temperature range and has a usb output. My question therefore is can I connect this device to the Arduino? I have searched the web and found a few places that say it can be done, but they have very limited details and don't make it clear if this is for a sensor with usb output.

Many thanks

2

There is a host shield available which provides a USB port that you could connect the sensor to. In order for it to work you would need to provide some driver code to tell the device what to do; I have no idea how difficult that would be, but you'd need to know the messaging protocol the device uses to have any chance.

3

first, I would recommend looking at this thread http://www.phidgets.com/phorum/viewtopic.php?f=1&t=5240

Also you are going to find out if your device supports l2C. This is one way that the arduino can communicate with external devices. It can also communicate through serial connections as well. The way you will find out is by reading through the devices datasheet. Once you have that, you basically should have all your answers.

4

Thanks for your reply. Would you be able to point me in the direction of the shield?

Is there an easier way to read thermocouples from an Arduino? I haven't been able to find a solution that has good resolution in the range I need.

5

Lemme look around for a sec.

6

Okay so tell me if you have this temperature sensor; 1124 User Guide - Phidgets Support

If you do then you are in luck. The sensor operates as a basic analog output in that you supply power to in through a Vcc and there is also a ground connection and then you have an extra connection which is where the device outputs its sensor value. What you will do with the arduino is just this:

analogRead(sensorpin);
int tempC = (SensorValue x 0.2222) - 61.111;

the value of sensorpin is whichever pin you have it connected to. You will have to connect it to an analog header on the arduino. Those are addressed like this:

sensorpin = A0; or sensorpin = A1;

It is whichever analog pin with an A in front of it.

7

No, unfortuately not. I have this one 1048 User Guide - Phidgets Support any chance that would work too?

Does the solution in your reply require adding additional connections to the Phidget board, or are you connecting to the Arduino using the usb connector somehow?

Thanks again

8

scratch that last question. I can now see that module you have linked to does does connect via usb

9

So it looks like I can't connect my Phidgets device to my Arduino :frowning:

I need to read in temperature values from between two and four k-type thermocouples, my expected temperature range is [-100, 200]C. Can anyone offer any suggestions on a way even I can achieve this?

Many thanks

10

Take a look at this: Thermocouple Amplifier MAX31855 breakout board (MAX6675 upgrade) : ID 269 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits

And this: Thermocouple sensor tutorial

11

Thanks, I will definitely look into this. Looks like it would work a treat.