# Multi digit BCD to LED circuit

Discussion in 'The Projects Forum' started by Craig Tull, Feb 6, 2012.

1. ### Craig Tull Thread Starter New Member

Jan 17, 2012
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0
I am in need of a bcd to multi diget seven segment circuit to give me a readout of a 5 bit bcd input (00-31) I can find all kinds of counter circuits but nothing to directly convert 5 bit bcd into a two digit display.
Thanks
Craig

2. ### MMcLaren Well-Known Member

Feb 14, 2010
759
116
Would something like this work (below)? A couple of us came up with this PIC project a few years ago but the program would need to be modified to display decimal values instead of hexadecimal values.

Regards, Mike

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3. ### spinnaker AAC Fanatic!

Oct 29, 2009
5,102
1,190
And there are BCD to 7 Segment display drivers out there.

But you need to know if your display is common anode to common cathode.

4. ### crutschow Expert

Mar 14, 2008
13,508
3,385
A BCD value of 31 requires 6 bits (four to represent 0-9 of the one's digit, and two to represent 0-3 of the ten's digit) so you apparently have a 5-bit binary number, not a BCD number. A binary number cannot be easily turned into BCD with simple logic. For that you need a binary to BCD conversion circuit and then a BCD display driver.

5. ### Craig Tull Thread Starter New Member

Jan 17, 2012
13
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Yes I guess it is just binary 00= 00000 and 31= 11111, sorry, I just can't understand with a bazillion chips out there....

6. ### Craig Tull Thread Starter New Member

Jan 17, 2012
13
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Mike that looks like it would be perfect, unfortunately I am not much on writing code. I am much better at implementation than design.
Craig

7. ### MMcLaren Well-Known Member

Feb 14, 2010
759
116
Modifying the code for your 5-bit binary to 2-digit decimal requirement is relatively easy. Do you have access to someone who can program the PIC device for you (you haven't included location information in your profile).

Regards, Mike

8. ### LDG New Member

Feb 10, 2012
4
1
I built this circuit ot aid in PIC chip programming.

if you are interested I can email you the HEX file for the
PIC16F870 microcontroller.

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9. ### Craig Tull Thread Starter New Member

Jan 17, 2012
13
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Yes please do, this looks interesting!
<SNIP>

Last edited by a moderator: Feb 15, 2012

Apr 5, 2008
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Hello,

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