Resistive type temperature sensor question. Non basic stamp ?
Jimbo30
Posts: 129
With any resistive type sensor and especially a temp sensor what is the best way to convert that resistance to temperature and display it on an LCD screen or 7 segment display? If someone could kindly explain this to me that would be greatly appreciated and thank you.
Comments
If you're using a Propeller, there's an application note (AN001) that shows how to use two I/O pins to make an ADC (analog to digital converter). You can also use the same technique as used with the Stamp's RCTIME statement. There's an equivalent in the BS2_Functions object in the Object Exchange. The Propeller can easily drive the same sorts of displays or use a TV or VGA monitor.
If you want to use some other kind of microcontroller, the same techniques can be used, but we can't help you other than to offer the Stamp and Propeller examples as models.
The resistive type temperature sensors have a non-linear response to temperature so a straight conversion using a voltmeter chip or adc would give a very inaccurate reading at all but one or two temperatures. At one time analog circuitry was used to produce a linear response but it is much simpler and cost effective to have a microcontroller do that. If you absolutely must do it without a microcontroller I would suggest using an adc with its output going to an eeprom with a look up table to do the conversion. Been there, done that, and it is not as simple as using a microcontroller either, but better than the analog route.
Mike this is a great idea, thanks. I will take a look at this route.
What fun would that be?
...depends on how quickly you wish to be done!