strokedmaro said:
Is there a way to get a seven segment to display numbers 1,2,3 and 4 with only 2 inputs?
Basically
1=on,on
2=off,on
3=off,off
4=on,off
Yes, I think it is with suitable logic, but I don't think it is all that simple.
From your initial enquiry---
I presume you want to display 1,2,3,4
NOT 0,1,2,3
Nearly all logic devices (counters/ displays) are manufactured to count/display from 0- 3 ---> etc. So you will have to use an adder to increment a zero state (on,on) to (on,off) to satisfy a display module. A cmos 4008 will do that.
I also presume that you want to interpret the state of
two lines, not a counter, hence you need a binary decoder. All I can see in the cmos is a 4555 that will give an A,B,C,D output.
I can not find a 7 segment display that will give 1,2 3,4 outputs with A,B,C,D inputs. EG 4511 will give A=1 B=2 BUT C=4 and D=8, So you will need to split the C and D outputs with Diodes to make discreet 4511 inputs C= (A+B inputs) and D = (
NOT A+B+ C inputs)
This is an interesting exercise and I will have a go at it myself.
There are probably many other ways to do all this, but I can only see this way.
Cheers
RH