16 Bit Gray Code Encoder Circuit Problem

Thread Starter

waynehamradio

Joined May 26, 2005
1
Hello everyone; This is my first post.

I built a 16 bit, 4 concentric circle Gray Code Wheel, with Infrared emitters and detectors to read the Gray Code to drive 16 small LEDs arranged to indicate every 22.5 degrees of a compass circle. The object of this device is to indicate the direction of a remotely located direction finding loop antenna.

The Gray Code wheel encodes properly in sequence with one exception. When it is rotating clockwise with the loop , the indicating LEDs are going in the opposite direction. Same for counter clockwise rotation of the code wheel, as the LEDs go in the opposite direction as the loop.

Electronically, the whole system is done with hardware, no PC or software involved, with the code wheel segments being "read" by the IR phototransistors which feed a non-inverting LM339 comparitor. The comparator feeds a 7486 Gray Code to Binary converter which feeds a 74154 demultiplexer to light the proper LEDs in sequence.

I can't find a solution to get the LED sequence indicating the same direction as the actual loop rotation.

Appreciate any and all suggestions, corrections etc.
 

beenthere

Joined Apr 20, 2004
15,819
To the OP: These are public forums. It is against the spirit of the public nature of the question and answers to make them in private.

To the email question:
Hello; Thank you for the response to my post. At this time I don't have a flat bed scanner to send a wheel diagram or a schematic. I guess I will have to invest in one very shortly. A reply from you would be appreciated.
I can't reply because there is no schematic to examine.
 
Top