Hi!
I'd like to use a rotary encoder in my design and to make the MCU job easier I decided to use this circuit:
https://basicelectronic.blogspot.com/2006/08/rotary-encoder-converter-circuit.html
I'm using an NXP 74HC74D chip and a Bourns quadratic incremental encoder. I've built the circuit on breadboard with two LEDs hooked up to the Q outputs of the flipflop. The output pins of the encoder (A and B) are pulled up to 5V with 10K resistors, the common pin is to GND.
I was expecting to see when rotating the encoder shaft there is only one LED flashing at a time. However both LEDs are flashing always: one is by the expected rate of the rotation, the other one is by every second or fourth 'click' of the encoder shaft.
I checked the breadboard several times and there are no errors in the wiring. I simulated the circuit in multisim which confirmed the expected behaviour of the circuit and did not showed the behaviour I experienced.
I also checked the encoder with a scope and it is functional. Both A and B pins are signalling high and low states and their order is changing according to the direction of the rotation.
I'm out of ideas now. Any tip or idea would be highly regarded. Thank you!
I'd like to use a rotary encoder in my design and to make the MCU job easier I decided to use this circuit:
https://basicelectronic.blogspot.com/2006/08/rotary-encoder-converter-circuit.html
I'm using an NXP 74HC74D chip and a Bourns quadratic incremental encoder. I've built the circuit on breadboard with two LEDs hooked up to the Q outputs of the flipflop. The output pins of the encoder (A and B) are pulled up to 5V with 10K resistors, the common pin is to GND.
I was expecting to see when rotating the encoder shaft there is only one LED flashing at a time. However both LEDs are flashing always: one is by the expected rate of the rotation, the other one is by every second or fourth 'click' of the encoder shaft.
I checked the breadboard several times and there are no errors in the wiring. I simulated the circuit in multisim which confirmed the expected behaviour of the circuit and did not showed the behaviour I experienced.
I also checked the encoder with a scope and it is functional. Both A and B pins are signalling high and low states and their order is changing according to the direction of the rotation.
I'm out of ideas now. Any tip or idea would be highly regarded. Thank you!