I have Freeduino, like Duemilanove, board with ATMega32 microprocessor.
I have JHD 162A digital display.
As a trial/hobby, I want to program a micro-controller, using methods described on arduino.cc website to get a digital clock.
I am almost done with the needed sketch for it.I have two questions.

Question 1:What is the right inexpensive choice for micro-controller for it ?

I am still searching on internet for guidance.
I feel that I can easily add room temperature display in it also( as it is available in a ready made digital clock.

Question 2:Which thermistor should be used?

I will have to modify the sketch if I decide to add thermistor (provided I can calibrate it!)
The requirement on micro-controller is therefore
a. one long millisecond variable, and
b. running the sketch.
Is this information enough for deciding micro-controller ?

 

I think this decision must be made by the designer (means you).

For a single circuit it does not matter- most controllers are inexpensive.

Savings are only visible when you produce at least a few 100 PCBs.

And 2.) use a I2C temp. sensor for instance Microchip.
The thermistor calibration is a lot of effort.

 

1: I don't understand why almost all beginners start with Arduino when there is a more useful direction that can help more in the future professional career. For beginners and beyond, a development board like the one here:
http://www.mikroe.com/easyavr/
together with related software and programming the examples are given here, can help a lot more to learn how to interface different modules and use microcontrollers. Why you do not use this way?

2: Uses one LM35 interfaced one of ADC pins of the microcontroller if you want MCU read and displayed the room temperature. It is the most simple and accurate method.

 

2. I don't understand why anyone would use an LM35 when it is a complicated mix of hardware software and calculations when you can get something like a TMP275 which does the complete conversion internally, only requiring you to read the number off a serial interface.

 

2. I don't understand why anyone would use an LM35 when it is a complicated mix of hardware software and calculations when you can get something like a TMP275 which does the complete conversion internally, only requiring you to read the number off a serial interface.

Thats easy.. its through hole..

1: I don't understand why almost all beginners start with Arduino when there is a more useful direction that can help more in the future professional career. For beginners and beyond, a development board like the one here:
http://www.mikroe.com/easyavr/

another easy one.. Its $20 vs $150 and has its own simple,easy to learn ide/language plus thousands of online tutorials/example code..

 

I don't understand why you are asking for a micro solution when you stated you have a freeduino.. use that.

 

I don't understand why you are asking for a micro solution when you stated you have a freeduino.. use that.

Thats easy...the OP did not know

 

1: I don't understand why almost all beginners start with Arduino when there is a more useful direction that can help more in the future professional career. For beginners and beyond, a development board like the one here:
http://www.mikroe.com/easyavr/
together with related software and programming the examples are given here, can help a lot more to learn how to interface different modules and use microcontrollers. Why you do not use this way?

<snip>

Might have something to do with the $149 price tag vs <$30 for the Arduino. True, there is a lot more hardware with the Microe, but for a beginner, just a couple of externals will get someone started.

 

I think this decision must be made by the designer (means you).

For a single circuit it does not matter- most controllers are inexpensive.

Savings are only visible when you produce at least a few 100 PCBs.

And 2.) use a I2C temp. sensor for instance Microchip.
The thermistor calibration is a lot of effort.

.......
Thanks.
1. I read a lot on internet about choice of micro-controller. I couldn't get one that can use sketch developed by arduino board.Hence the question.
Atmega32 cost around Rs.200(in India) and there are some at around Rs.30 or so. For a mere hobby, it is worth saving!
I thank you for you taking out time and answering my query.It encourages and helps.
S.R.Paranjape

 

1: I don't understand why almost all beginners start with Arduino when there is a more useful direction that can help more in the future professional career. For beginners and beyond, a development board like the one here:
http://www.mikroe.com/easyavr/
together with related software and programming the examples are given here, can help a lot more to learn how to interface different modules and use microcontrollers. Why you do not use this way?

2: Uses one LM35 interfaced one of ADC pins of the microcontroller if you want MCU read and displayed the room temperature. It is the most simple and accurate method.

...
Thanks for very prompt comment/advice.
My hobby is for learning something new for pleasure of it. The board, I am using was easily available in my city and internet search indicated that one could search for help. There is no idea of using it for any other purpose.
I would check availability of LM35 in my city and what I would have to learn more to use it.
Thanks again
S.R.Paranjape

 

I don't understand why you are asking for a micro solution when you stated you have a freeduino.. use that.

Sir,
I would like to experiment of making a supportive power supply of 5vcircuit , see how to program a microcontroller to go in its place in the circuit, and experience fun of making a stand alone unit ith smaller no of parts than on the development board.! It is just a hobby to see how entrepreneurs might have developed it.
S.R.Paranjape

 

If you want to stay with something similar to arduino
then
http://arduino.cc/en/Tutorial/ArduinoToBreadboard
http://arduino.cc/en/Main/Standalone