Hello all I have built a systhesized MW receiver and am using a Bourns 24 pulse/rev PEC series switch type incremental encoder for the tuning control. It's a detented encoder with an independent push button switch. The data sheet claims 5ms of bounce at 15 RPM. I am using a PIC16f628 to monitor the encoder and to control the synthesizer chip and an LCD. The PIC is run in a simple loop polling one of the encoder switch inputs and the other push button switche and a seperate toggle switch. If it sees the encoder switch go low it immediately checks the other encoder switch input to determine which direction the encoder was rotated, then enters a debounce delay, then waits for the encoder to go back high again before reprogramming the synthesizer and updating the LCD. All switches are pulled to +5 via 4.7K resistors and all PIC input lines are schmitt trigger inputs. It works except that the debounce delay has to be streached out to 40ms to even be usable. Even at 40ms it still bounces intermittently. I initially had it checking the second encoder switch after the debounce delay but that was much worse. I tried putting 10nf caps from the input pins to gnd and that seemed to make it worse. It don't believe it is picking up noise because the other pushbutton switch input gives me no problems at all. Oh yeah, I have tried replacing the encoder hoping that I had a defective one.
I am NOT a programmer, so I took the simplest approach I could think of in using the encoder and I suspect that I'm missing something here and would sure appreciate any help at all.
They were pretty cheap. only about $1 ea from Mouser, so I got 10 of them hoping to use some in other projects, but that doesn't look too promising. These encoders also have nasty tendancy to stop between detents unless care is taken when rotating it. I'm not real sure what good a detent is if it stops between them.
TIA Mike