8051 Temperature Sensor

[Meesam]

Hello everybody.
I am working on a project to build up a simple temperature sensor using the 8051 MCU. Main components of the project are as follows.
AT89C52 MCU,
LM35DZ (temperature sensor)
ADC0804 (analog to digital converter)
Any kind of display.
Well my current problem is the suitable kind of display. If i use 7-segments then they really create a problem of port pins shortage as i'll have to already set aside one and a half ports for signals and data from ADC0804. Another option is 4x7 segments but they have problem that they are most of the times difficult to find with part numbers and their controlling is another issue. What i want is a nice and noble solution to this problem of displaying the data of temperature.
If i get it done then i'm planning to extend this project so that i receive the data wirelessly from the temperature sensor and display it separately.
Anybody wishing to join hands with me, suggest something or anything of a good piece of advice can contact me either here or on my mailing address.
syedmeesamali@yahoo.com,
i'll welcome any response from anybody.

 

[Analog]

You haven't mentioned how many port pins you have available. Did you consider multiplexing the display to save pins? You can also offload some of the display chores to a PIC via serial to save even more pins. Lots of options here.

 

[Meesam]

I am basically using AT89C52 with Port 1 dedicated to get the one byte of data from the ADC804. Some pins of Port 3 are used for control signals for ADC804. Now I am left with two complete empty ports i.e. Port 0 and Port 2. It is quite easy to connect the two 7-segments to these two ports. But if I connect all this then there will be a huge wire mesh over the entire circuit and it won't be nice to look at, let alone handling it or modifying it. What i want is that I use only one of these ports to control the two 7-segments. I know that multiplexers can be used to do this. But right now I don't have a very clear cut idea how to achieve this. Please can you help me for this.
I am waiting for reply. I shall be thankful for that.

 

[sci-3d]

I don't understand your problem, the hardware or programming, you struck are.

See this From Maxim, you may have an idea:

**broken link removed**

 

[Meesam]

I know how to program but my main theme is how to wire up the things. I mean how can I connect a multiplexer with the port and get the things working. Remember I have a 10 pin 7-segment with also a decimal point. So i'll have to be trickier in connecting to it.
Please reply if you have idea how to do this.

 

[Aily Sajjad]

IF you just want to save the pins of MCU. Then better use the serial communication with the MCU. Get the display data serially, use serial to Parallel converter and feed to display drivers. You will definitely have to add more chips to your circuit and wires will remain same (as many as the segment pins are).

 

[Meesam]

Thanks everybody for the support !! I completed this project now 4 years back !! Got reminded of this post by someone on my email id !!
Thanks everybody

 

[khairulk]

Can you email your completed project please...I want to review it for my project...
aremyer@yahoo.com

Thank you.