How can I display temperature in 3 to 7 segment led without using Arduino and also the digits on the led should able to increase or decrease when the pot turn clockwise/anticlockwise

 

Use a different MCU.

What you want would require a lot more work using discrete logic than with an MCU. But you don't have to use an Arduino, or certainly not a big one. The much smaller MCUs readily available could be used. If you are thinking of an Arduino Uno, that's just physically too large for a project like yours.

 

https://www.digikey.ch/htmldatasheets/production/38276/0/0/1/icl7106-07.html
ICL7107 with an analog output sensor like LM35 would do it with no microcontroller.
https://www.ti.com/lit/ds/symlink/lm35.pdf?HQS=TI-null-null-alldatasheets-df-pf-SEP-wwe

 

https://www.digikey.ch/htmldatasheets/production/38276/0/0/1/icl7106-07.html
ICL7107 with an analog output sensor would do it.

How would you set the number of digits with a knob?

 

How would you set the number of digits with a knob?

Hmm.. I read it as a 3 digit display and a pot to simulate temperature. If your premise is correct, yep some microcontroller.

 

One of the problems is most temperature sensors such as thermistors are non-linear, except LM34 and LM35.
How are you going to correct for non-linearity?

 

Here is my mind reading version, the TS can confirm if I am correct or not:

"I want to display the temperature with 3 to 7 significant digits on a 7-segment, 7 digit LED display. I want the significant digits to be adjustable with a knob."

I think that is right, but I wouldn't bet too much money on it.

 

the digits on the led should able to increase or decrease when the pot turn clockwise/anticlockwise

What, exactly, does that mean?

 

What, exactly, does that mean?

My crystal ball says the values displayed, with up to 7 digits, change by turning a knob which simulates a temperature sensor output.

 

I think I get it now. TS wants a bar display such as an LM3914 driver IC.

 

My crystal ball says the values displayed, with up to 7 digits, change by turning a knob which simulates a temperature sensor output.

This is the type of LED I was talking about 3 digits 7 segment

 

That do you want the knob to do?

 

That do you want the knob to do?

Yes, but I don't know if it will be possible. I have seen a hot air blowers which the knob can be used to set the temperature and it displays the temperature in digits on the led.

 

OK, so let's figure out what you actually want. Do I have this right?

You want a temperature controller with a set point control with 1° resolution, and three digit readout of the set point while it is being adjusted, but once that is done, it should switch to showing the current temperature.

Is that right?

 

Very hard to beat!

Otherwise, if you want to build it yourself, a processor of some sort will be needed, and an Arduino is the easy way to go as there are many examples around for you to copy, and plenty of on line help.

 

Yes, but I don't know if it will be possible.

Anything is possible. You just need to clearly define exactly what it is that you want to happen.
Maybe language is a barrier. But no problems. We are willing to work it through with you.

 

View attachment 259219
Very hard to beat!

Otherwise, if you want to build it yourself, a processor of some sort will be needed, and an Arduino is the easy way to go as there are many examples around for you to copy, and plenty of on line help.

I fear, and it was my next question, that the temperature range required by the TS will be in excess of 110°C. And, these modules and their many variants don't have rotary controls, but I hope that's just on the wish list.

 

Anything is possible. You just need to clearly define exactly what it is that you want to happen.
Maybe language is a barrier. But no problems. We are willing to work it through with you.

So let's make it clear.

1) You have a 3-digit display.
2) You have a temperature sensor.
3) You have a control knob that you can turn.

What is supposed to happen?

 

OK, so let's figure out what you actually want. Do I have this right?

You want a temperature controller with a set point control with 1° resolution, and three digit readout of the set point while it is being adjusted, but once that is done, it should switch to showing the current temperature.

Is that right?

Exactly

 

Exactly

What it the temperature range—from low to high—that you want to cover, and in C or F?
What does it have to control?
Where does the sensor have to go?
What voltage will it have to switch, what will it have to be powered by?