BCD 2 decimal (need help)

[dk_hassan]

I have got dual 7segment displays(10pins, 16pins & 18pins).. they are common cathode... and driver IC 7448....
my objective is to provide 4bits BCD using switches and want its corresponding decimal on display... means my work would be from 0 to 15... or 0000 to 1111(on input side)... or you can say that i want to make BCD to DECIMAL converter...

My question is how to do this... and which segment is feasible and easy to use.. 10pins, 16 or 18?? Remember that i want to display from 0 to 15..!!

Please reply ASAP.. thanks..

 

[dk_hassan]

Also suggest If i need to change the driver IC or 7segment..!!

 

[ericgibbs]

Also suggest If i need to change the driver IC or 7segment..!!

hi,
The 7448 LED display pattern is shown in this image.
0 to 9 with 5 symbols



To display 0 to F you require a different decoder or use a PIC.

This would be an 4 bit binary to hex converter.

or you can say that i want to make BCD to DECIMAL converter...

 

[Reloadron]

Does this new thread have a connection to this earlier thread?

If you are using two BCD to 7 segment decoder drivers (one for each display) then please state so. Are you wanting to go from BCD to Decimal as the thread states or BCD to 7 segment display?

Ron

 

[crutschow]

0 to 1111 is binary (HEX), not BCD which is Decimal (as in Binary Coded Decimal). BCD is 0 to 1001. Sounds like you need a Binary-to-BCD conversion to display two decimal digits, which is more complicated. See this thread.

 

[jbeng]

Considering the amount of requests I've read for hexadecimal- or binary-to-seven segment converters, I'm surprised that someone who has knowledge of microcontroller coding doesn't program some as such and sell them as a product.

Seems to me an easy way to make a few bucks...

 

[ericgibbs]

Considering the amount of requests I've read for hexadecimal- or binary-to-seven segment converters, I'm surprised that someone who has knowledge of microcontroller coding doesn't program some as such and sell them as a product.

Seems to me an easy way to make a few bucks...

hi,
This link is on the forum, also a 3 decade bin to hex PIC project was shown on the Forum last year.

https://www.electro-tech-online.com/content/149-binary-7-segment-decoder.html

 

[crutschow]

They used to make a chip that converted binary to BCD, but it's no longer available. Apparently not enough demand.

 

[dk_hassan]

yeah.,.. sorry I want a binary to HEX technique...? As i am new to it so dont know how and what to do..
please give me any circuit diagram.. or IC number through which i can do this.. thanks


@Reloadron.. no that thread is for something different..

 

[crutschow]

yeah.,.. sorry I want a binary to HEX technique...? As i am new to it so dont know how and what to do..
please give me any circuit diagram.. or IC number through which i can do this.. thanks

Just to be clear. Do you want to show DECIMAL or HEX on your display? For example, do you want BINARY "1100" to display as DECIMAL "12" or as HEX "C".

You originally said you wanted to display decimal.

 

[dk_hassan]

i want to display 12.. means want to display decimal from 0 to 15..

 

[crutschow]

i want to display 12.. means want to display decimal from 0 to 15..

Then you want to do a binary to BCD conversion as I stated in my previous post.

So you need to use one of the methods described in the referenced thread: a micro-controller, a PROM, the down-binary to up-BCD counter approach, etc. There is no chip available that will do this.

 

[Midon]

There is no chip available that will do this.

Try the ICM7212 from Maxim - it is 4 digits but does hex binary to 7 segment conversion, however does not do exactly what the OP wants to do - display binary to decimal.

The Fairchild DM9368 also does this, but it is now obsolete - might find some on the gray market or eBay.

 

[Reloadron]

i want to display 12.. means want to display decimal from 0 to 15..

OK since you mention a 7448 decoder driver and since you mention two displays I will assume you want to simply display a number based on inputs to the 7448s? The attached would display a 13 as drawn. Your displays would be Units, then Tens right to left looking at your displays side by side. Maybe this makes sense? I used dip switches to input to the 7448s. All you need to do is place the appropriate pins to common.

That's how I read what you want to do anyway and I may be wrong.

Ron

 

[crutschow]

OK since you mention a 7448 decoder driver and since you mention two displays I will assume you want to simply display a number based on inputs to the 7448s? The attached would display a 13 as drawn. Your displays would be Units, then Tens right to left looking at your displays side by side. Maybe this makes sense? I used dip switches to input to the 7448s. All you need to do is place the appropriate pins to common.

That's how I read what you want to do anyway and I may be wrong.

That won't work. He stated he wanted to convert a 4-bit binary number from 0000 to 1111 to decimal. For that you need a binary-to-BCD conversion.

 

[Reloadron]

That won't work. He stated he wanted to convert a 4-bit binary number from 0000 to 1111 to decimal. For that you need a binary-to-BCD conversion.

Oh, I absolutely agree. He also mentioned 7448 and a pair of 7 segment LEDs. I assumed a pair of each. OK, all things considered, what does he want as I am clueless. I am sure he knows what he wants but he can't seem to express what he wants. That leaves an audience guessing what he wants. This is like:

I have two seven segment LED displays. I have two 7448 decoder drivers. How do I display a number between 00 and 99? He states he wants to make a BCD to Decimal conversion and uses 0000 to 1111 as an input. Not going to happen with the parts he listed that I can see?

Beats the hell out of me.

Ron

 

[benitosuave]

Seems like a microcontroller's job to me.

 

[dk_hassan]

I just want to give 4 digit binary input... and want the corresponding decimal on display... Since the input is 4digit... So the maximum number that would be displayed is 15.. No matter what IC, I mentioned, As I had written that suggest any other IC also.. And Also the display with number of pins... like I have three types of displays... 10pins, 16pins, 18pins.... All are common cathode....

I hope I am clear this time?

 

[crutschow]

And is it clear that you need to do a binary-to-BCD conversion for this, for which there is no available standard IC? What you want to do sounds simple but it is not. You need to use one of the techniques I have previously listed. Sorry, there's no shortcut to this.

 

[olivergreen]

I think you need some thing like this
**broken link removed**