Hello, first time poster here, have read a few project posts and am very encouraged to have found - and become a member of - this forum. I hope that you guys can help me!
My project involves car electronics / stereo. I wish to use my stock cassette radio to control an after market stereo. Basically, I have a hidden after-market "brain" that is ready to accept several functions from the factory steering wheel controls. As you can imagine, the steering wheel controls include a + and - momentary toggle switch for volume.
However, I would like to crack into the wiring of the volume knob (rotary encoder) on my factory cassette radio and use it to control the volume of my hidden stereo brain. In other words, I want to convert the varying sine wave outputs from the rotary encoder into momentary pulses of "+" when moved clockwise (for volume up) and momentary pulses of "-" when turned counterclockwise (for volume down). The rotary encoder has detectable detents as you turn it in either direction, so if I turn it over three detents clockwise I wish that to translate effectively into pushing the volume "+" button three times. Are you with me?
If you don't know how rotary encoders work, i will explain: the rotary encoder has a wire going into it ("I", main pulse 5V) and two wires coming out of it ("A" and "B"). What happens inside: There are contact surfaces all around the rotary knob (detents, you can feel them as you turn the knob, and the knob rests in these detent positions), but they only come in contact with the board at two different points (let's assume 3 o'clock and something slightly past 9 o'clock). Once one of the multiple contact surfaces on the knob comes in contact with these two points (the origin of the two output wires, A and B), a sine wave is output through each wire. If you turn the knob clockwise, the sine wave output on A might be slightly ahead time-wise than the sine wave output through wire B. I assume this is a result of the position of the contacts and which closes first. Thus, the difference in phase of the two sine waves (on wires A and B) tells the system that the knob was moved clockwise. The reverse would be true when the knob is turned counterclockwise.
Is it possible to find a pre-fab circuit that can output a momentary pulse to my "+" or "-" volume-button-receiving input wires when it receives input from the clockwise or counter-clockwise turning of the rotary encoder? If so, please advise!!! If not, i will have to put something together on a circuit board. Assuming the latter option, read on:
So, on both wires "A" and "B" I have a continuous pulse (sine wave, albeit slightly out of phase with one another) once the knob is in resting position (a detent). The way I see it, I need to first interpret the two sine waves output and use a process of elimination so that when turned clockwise there is only sine wave (or pulse) output on one wire, and likewise the other wire for counterclockwise movement. The following circuit seems to provide this:
Electronic Device And Electronic Circuit: Rotary encoder converter circuit
Next, I need to somehow convert that pulse signal of clockwise movement to momentary DC output to my volume "+" input wire. Bearing in mind that this momentary DC output needs to be reliably sensitive to each turning (detent) of the rotary encoder, such as when i want to turn the volume from position "5" to "6" (one DC pulse to "+" volume input) vs. turning from position "5" to position "8" (three DC pulses to "+" volume input).
Is this clear enough? Please let me know if you can help, or if I have been unclear.
Thanks in advance!
My project involves car electronics / stereo. I wish to use my stock cassette radio to control an after market stereo. Basically, I have a hidden after-market "brain" that is ready to accept several functions from the factory steering wheel controls. As you can imagine, the steering wheel controls include a + and - momentary toggle switch for volume.
However, I would like to crack into the wiring of the volume knob (rotary encoder) on my factory cassette radio and use it to control the volume of my hidden stereo brain. In other words, I want to convert the varying sine wave outputs from the rotary encoder into momentary pulses of "+" when moved clockwise (for volume up) and momentary pulses of "-" when turned counterclockwise (for volume down). The rotary encoder has detectable detents as you turn it in either direction, so if I turn it over three detents clockwise I wish that to translate effectively into pushing the volume "+" button three times. Are you with me?
If you don't know how rotary encoders work, i will explain: the rotary encoder has a wire going into it ("I", main pulse 5V) and two wires coming out of it ("A" and "B"). What happens inside: There are contact surfaces all around the rotary knob (detents, you can feel them as you turn the knob, and the knob rests in these detent positions), but they only come in contact with the board at two different points (let's assume 3 o'clock and something slightly past 9 o'clock). Once one of the multiple contact surfaces on the knob comes in contact with these two points (the origin of the two output wires, A and B), a sine wave is output through each wire. If you turn the knob clockwise, the sine wave output on A might be slightly ahead time-wise than the sine wave output through wire B. I assume this is a result of the position of the contacts and which closes first. Thus, the difference in phase of the two sine waves (on wires A and B) tells the system that the knob was moved clockwise. The reverse would be true when the knob is turned counterclockwise.
Is it possible to find a pre-fab circuit that can output a momentary pulse to my "+" or "-" volume-button-receiving input wires when it receives input from the clockwise or counter-clockwise turning of the rotary encoder? If so, please advise!!! If not, i will have to put something together on a circuit board. Assuming the latter option, read on:
So, on both wires "A" and "B" I have a continuous pulse (sine wave, albeit slightly out of phase with one another) once the knob is in resting position (a detent). The way I see it, I need to first interpret the two sine waves output and use a process of elimination so that when turned clockwise there is only sine wave (or pulse) output on one wire, and likewise the other wire for counterclockwise movement. The following circuit seems to provide this:
Electronic Device And Electronic Circuit: Rotary encoder converter circuit
Next, I need to somehow convert that pulse signal of clockwise movement to momentary DC output to my volume "+" input wire. Bearing in mind that this momentary DC output needs to be reliably sensitive to each turning (detent) of the rotary encoder, such as when i want to turn the volume from position "5" to "6" (one DC pulse to "+" volume input) vs. turning from position "5" to position "8" (three DC pulses to "+" volume input).
Is this clear enough? Please let me know if you can help, or if I have been unclear.
Thanks in advance!