AVR mcu based thermostat with 7 segment LED and PTC (or NTC)?

[firewalker]

Is there any AVR mcu based thermostat (3 digit accuracy) with 7 segment LED and PTC (or NTC)?

I have found several thermostat projects using an AVR mcu. The most of them uses a smart display an a sensor DSxxx.


I would also find handy if you know anything for other (not avr mcu based, or without an mcu) thermostats with 7 segment display and an PTC or NTC?

[bbarney]

Why don't you make up your mind on what your requesting,the topic states

Re: AVR mcu based thermostat with 7 segment LED and PTC (or NTC)?

then at the bottom your asking for something else ?

Is there any other (not mcu based) thermostat with 7 segment display?

So what is it you want ?

[firewalker]

My primary goal was an avr based, seven segment display thermostat using a NTC or a PTC. I have searched for hours over the net. I didn't found anything. So I suspected that I won't find someone how knows something for such a thermostat. But, I had to ask.

My second goal was avr mcu-less thermostat.

Maybe I should have posted a new thread to "general-electronics".

[avrPassion]

Hi

It is so simple to design a thermostat yourself.
All members of ATmega family have 10 bit ADC which is enough for 3 digit.
to do signal conditioning on a sensor such as pt100 you should pass 100uA from it and then measure the voltage on it. You can use an OP07 op-amp to amplify the output voltage.
If you want, i can draw the circuit and post it here.

[firewalker]

Thanks you avrPassion. I will give a try.

[Manuel]

Well, related 2 3 DIGIT 7 segment LED display unit U can use a 0..100mV voltmeter from RS or FARNEL i'd say....then you can use a silicon based sensor such as MCP9700 from m..chip and a little OP circuitry just 2 enter in the range of the voltmeter....and the job is done.

maybe something like 522-339 from RS...expencive but functional...

A processor based can be realized and U will spend no more than 7$....but some rework will be involved in....

Tell us what would you like 2 to @ the end?

Let me tell you that U can also consider a sampling request from LASCAR.  http://www.lascar.co.uk/press/pdf/PR-10-02-UK.pdf at a cost of £15.50

CU

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