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7 segment display "help please"

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deakin09

New Member
hi all am very new to the world of electronics so please be forgiving for my lack of knowledge :confused:
what im trying to do is use three 7 segment leds that will between them count up to 100 by using a dial. so you turn it one way it counts up and turn it the othere way it counts down.
if some one could point me in the right direction i would be very greatfull thanks:)
 

blueroomelectronics

Well-Known Member
What sort of dial? A quadrature encoder? Almost any microcontroller can do this.

You might want to pick something similar if you're new to electronics.
 

deakin09

New Member
Thanks for the quick reply.
it sounds the best way forward. i would much aprishiated any cicuit designs that any one mite offer to help me move forward with my project. as mentioned before im new to electronics altho not completely unformiliar :p
thanks :)
 

deakin09

New Member
Thanks for the offer of your kit but if i can would like to build it from scratch my self so i can get a better under standing of the build as i intend to build bigger projects.
what im after is some advice to point me in the right direction such as skematics and the best ic to use like cmos or othere. and aventually would like to connect it to my computer through an interface as it will evenually be use to control a programe.
thanks for now.
 

crutschow

Well-Known Member
Most Helpful Member

Sceadwian

Banned
deakin, if you want to learn the first thing you should learn is that you shouldn't try to learn everything from scratch it's like trying to re-invent the wheel, it's a waste of time energy and money. Here's a few links to get your started in the right direction for micro controllers.
Microcontroller - Wikipedia, the free encyclopedia
Atmel AVR - Wikipedia, the free encyclopedia
PIC microcontroller - Wikipedia, the free encyclopedia

http://www.sparkfun.com
sells some nice PIC and AVR programmers and chips as well. The simple in circuit programmers are extremely inexpensive (less than 20 dollars) and the chips themselves range from less than a dollar to 5+ dollars. (US)

Blueroom also sells PIC programmer kits that are very nice.

One example of why you don't try to do everything from scratch in electronics is an automotive analogy. If you wanted to learn how to build cars would you start with smelting the metal for the engine yourself? Most sane people would not =)
 

deakin09

New Member
Thanks guys most helpfull
All thou Sceadwian you may have miss understood my intetions abit i dont intend on building a micro chip from scratch as your replay would seem to suchest.:rolleyes:
if i use your automotive analogy your right i wouldent melt the metal down my self for the engine i would just buy the engine just as i intend on buying the micro chip .Also with learning any new skill you must start from the beginning and learn all the building blocks needed to help you under stand whats going on.:confused:
If i where to buy a ready made kit well then i would of learnt very little which for a hobyest like my self would seem point less and takes the fun out of it
but thanks for your comments :)
 
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Mikebits

Well-Known Member
Thanks mike this should help me alot :)
There are many more threads like that on this forum, just try the search function. I do think it is best to learn the basics like the difference between ohms law and Murphy's law before jumping into MCU design. I have done neither in 10 years or more, so I may not be best to advise... :)
 

deakin09

New Member
There are many more threads like that on this forum, just try the search function. I do think it is best to learn the basics like the difference between ohms law and Murphy's law before jumping into MCU design. I have done neither in 10 years or more, so I may not be best to advise... :)
Thanks mike
 

farhan looks

New Member
7 segment display

What is the need of using the dial.


just use three 7 segment dispalys cascade them with(7447) decoder driver if u r using common anode displays. use counter (7490) 4-bit asynchronous ripple conuter. give clock pulse from 555 timer at 14 pin of first counter and take a wire from 11 pin of the first counter to 14 of second and son on.


Rememberu have to use one(7447) and one(7490) counter to drive one display.

divide counter by 10 so that it may count from (0-9) by making 12 common with 1. and groung 2,3,6,7 pin of counter.


It works well thank you.
 

deakin09

New Member
Thanks farhan well worth looking in to.
iv had a brain wave in regards to encoder pot could i use the motor out of an old hard drive as i have loads about the place if memory serves me right when turned it will give a puls as it is basicly a stepper motor
any thoughts ?????
 
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farhan looks

New Member
sorry but i couldn't get your question about the stepper motor plz. first tell me what u want to make, and how?
 
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deakin09

New Member
What I’m trying to do is use three 7 segment LEDs that will between them count up to 100 by using a dial. So you turn it one way it counts up and turn it the other way it counts down.
I’m thinking of using incremental encoder pot with Connect the decoder output to three BCD up/down counters such as a CD4029.
i am a big fan of using what I’ve got and I think that the motor of a hard drive could be used as the incremental encoder pot because as it turns it will give a high and low signal but I’m not a 100% sure if it will work
 
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crutschow

Well-Known Member
Most Helpful Member
The encoder has to have a two-phase quadrature output so you can determine which direction it's turning. I don't think a motor has that. That's why I suggested using an encoder pot in my previous post.
 
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