This will be one of my first projects.

The Temperature sensor I plan/planned to use is the LM35 - Precision Centigrade temp sensor.
http://www.national.com/mpf/LM/LM35.html

Would it be best to use a analog sensor or a digital sensor? Does anyone have a schematic for some thing like this, with a LCD, the temp. sensor and micro-controller?

What micro-controller would you recommend for something like this?

 

You can use either. If you are only doing one sensor then both work about the same for you.

If you use the analog part you need to understand how to do the analog to digital conversion on the micro controller.

If you use the digital part you need to understand the communication protocol that the part uses.

Both are fairly simple. If you goggle you should be able to find several examples of each.

We most often use PICs here but most any modern uC will be OK.

 

of course, u dont have to use a uC, u could try an analogue to digital display convertor. maxim, intersil and whatnot have these parts for free samples, so you could give it a go. Although, u need LED displays and i haven't had much luck with them in the past. Just a suggestion.

BTW: the suggested schematic is on the datasheet.

__________________
-michael11298

 

Try LM75 which is said to have digital output.

__________________
Regards,
Sarma.

 

The schematic for this thermostat is on my site (Cricket)

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

132 !! I think you need an air conditioner

 

Lol actually it's the sensor A/D reading raw in hex with a 2.5V vref.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

Those sensors put out a millivolt per degree. If you don't need to read over 200 look at the pre-built digital panel meters based on the 7107/7106 chip (one is LCD one is LED, I can never remember which is which). You can find many versions on eBay for under $15 USD. You can scale the input if you need over 200, but the native full scale of the 7107/7106 is 199.9 millivolts.

 

I think that it is 10mV/°C

Mike.

 

Hello all

Well I have worked on this project. I used a 0804 A/D converter and seven segments. It was a weekly project of my Microprocessor Interfacing lab. Although i used a AT89C51 but I realized that there was no such need of Such a big microcontroller. Now when I am familiar with PICs I think a small pic with would be enough Rather I recommended using Pic for this project.



Although I have not worked on PICs but I have heard some pics have built in A/D converter, if this is true then i think all You need is a PIC LM35 and a Display

__________________
Khizer Naeem Mughal
IIUI

 

nowadays, even the ADC can be done by the same processor and perhaps we can avoid the ADC even. These specs of what elements to use are given to students, in order to train them to be able to write proper software, in case if micros and realise and sort hardware issues in case of ICs like 7106(7).

__________________
Regards,
Sarma.

 

Yes, I was remembering wrong. It's 10mV per degree (the LM34 is degrees F). So you would maybe have to use a resistor voltage divider. It depends on what temperature range you need to measure.

 

0 - 100 `C range the Vref for 0804 will be 2.5 volts. For that you need a POT and a zener diode

__________________
Khizer Naeem Mughal
IIUI