Hello,

This is my first post on this forum, I'm newbie and don't know much about electronics.

I want some (little bit) of help on how to display LM35 temp out on 7-segment w/o using uC. I had searched on google but didn't find what i was looking.

Why im asking for w/o uC is bcz i found every site using uC for temp out.

I can get Temp in C and can convert it to digital using ADC0804 but wot to do then? I havn't studied A to D Conversion yet so thats why im stuck, please help me out.


Thanks

 

try the ICL7107. http://www.intersil.com/data/fn/fn3082.pdf
It's an ADC and LED driver all in one. JDR has them for like $2.40

 

Thanks for your reply, well is there any alternative solution. May be this won't be available in local market(i will try to search it) and haven't much time to order it online.

Some simple and illustrative design ... thanks

 

It's a standard IC, but it is old, and probably heading towards being obselete? - micro-controllers have rendered them pretty well pointless now.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Microcontrollers seem to have replaced most of those old ICs.

Here's a LM75 with seven segment display, but it's all digital with a 16F628. Course my Cricket is of similar design. :-)

http://www.100acre.org/elec/lm75/

Hey some really great ICs are long gone with no replacements.

The TI 9918 'Great little video chip
GI SPO-256-AL2 'text to speech robot voice

__________________
Bill
Home of the
Firefly PIC Tutor
Inchworm ICD2

http://www.blueroomelectronics.com

 

there seems to be a pretty good on-line stock of them. findchips shows a good number have them in stock.

Mouser has them, no minimum and if you take first class USPS shipping, it will cost on the order of $3. so total is going to be like $6. My last order this way came in 2 days.

 

philba hi, ve been thinking of a cool project for my final year .i dont know if u ve any suggestions without using a microcontroller.may be temperature based or just any circuit that convert a physical parameter to voltage.am a final yr student of physics here in Nigeria

 

Hello there
i have a question..
can you please tell me if you know any site that has a schematic which shows how is connected the adc0804 with the icl7107?

i'd be grateful

eg: i want to connect LM35 with the adc0804 and then the adc with the icl7107. Then the output of the icl7107 is going to the lcd screen

 

They don't work that way. With the ICL7107 you don't need the ADC0804, and the ICL7107 drives 7 segment displays not LCD screens.
LM35>>>ICL7107>>>7 seg.led's.

 

oh..
i thought that the icl7107 was just the decoder that takes the output from the adc0804 and give it for input to the LCD (slf7080gc)
am i wrong?

anyway, i think you are right (thats why i cant connect them)
do you know what decoder i have to buy so as to make this row
LM35>>>ADC0804>>>__?__>>>3 1/2 seg.LCD

the adc0804 is necessary for my project...

thanks for the reply Brevor

 

a hint
http://www.play-hookey.com/digital/e...eg_driver.html

 

I think your "__?__" entry should read "binary-to-bcd converter >>> "bcd-to-seven-segment decoder-drivers".

You could program an EPROM to function as the binary-to-bcd converter and use 4543 (or 14543) driver chips, since they're designed to drive lcd's.

That's if you have to use the ADC0804. Is it required that you use it? Since the ICL7107 has an ADC in it, you could just connect the output of the LM35 directly to the input of the ICL7107, like Brevor said. Scaled appropriately, you could theoretically get a 0-200C display. That's assuming 10mV/deg C output from the LM35 and a full scale of 2V. The LM35 will only sense -55C to +150C, but it will still make very useful thermometer. Also, to drive an LCD, you'll need the ICL7106.
Jeff

__________________
Nothing is impossible for the man who doesn't have to do it himself - Weiler's Law