Counter Circuit 000 to 999 to be used on a Tape measure NOT WORKING

[Thedatsun]

I have a design for a counter that counts from 000 to 999 UP and Down on a LCD using a 555 timer to supply the signal CMOS ICs 4027 with a 4060 for the timing gate, 4029 Up/down counter, and 4543 for the LCD. However I am unsure why it will not count or at least display on the LCD. The only feedback I get is the blinking decimal and middle notches and not a full digit.

The counter is set up based on the diameter of the wheel that will be used on a Tape measure which equates to A mod 6 counter because the amount of pulses per revolution of the wheel.

Is there a problem with my Logic for the 4027 Gates?

Can someone examine the circuit and tell me if it will count from 000 to 999 with a leading zero?

Also can someone also tell me perferrably with a diagram how and where to wire in a Reset switch?

Where to wire in LEDs (2) to show max and min terms ?

Also where is the Phase A and B signal located in this circuit?


Thanks in advance for the help

 

[Thedatsun]

Bump for help

 

[picbits]

Start by just having your LCD and drivers, hard wire the drivers to display a certain number then work back from there.

Once you have got the LCD part working you can debug (if necessary) the counting part of the circuit.

Whenever you have a circuit that doesn't work, often by breaking it down into simpler "modules", you can discover what the issue is.

 

[KeepItSimpleStupid]

You do know that count to feet is not a linear function. I had to deal with this, but I had help. I don't have the equation any more. It does use initial diameter and turns. As the tape winds the diameter increases. It is solvable using integration. and s=rθ

 

[Norator]

If you know the tape thickness and the initial and final tape roll diameter you can calc. the tape length. Then each reel revolution adds a tiny but changing amount of tape length.

For a 6" reel with a 2" hub the tape area A is PI([3^2] - [1^2]) sq. inches. With a tape thickness of t the total tape length is A/t.

The first reel revolution n = 1 gives you approximately PIx2 inches of tape length and the last n = ? gives you ~PIx6, assuming t << hub diameter.

This gets interesting.