Incremental Encoder as front panel control

[john cutler]

Does anyone on this forum know of a good quality, not very expensive incremental encoder that might be suitable for front panel control replacement? I'm working on a project where I need to be able to preset from memory (e.g.) an audio level on a device , but also must allow the end user the ability to turn the level up or down from the preset value.

I've looked on line at some Bourns devices, but from what I can tell, the affordable ones only generate 6 pulses/rotation. I need much finer resolution than that.

Can anyone out there point me in a useful direction? Thanks.

John Cutler
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Original Post ID: 144515244

[Tomi]

<font face="Courier New" size=-1>Why do you need a rotary encoder? Take a look on your remote controllers (TV, Hifi tower, etc.). You can find a "+" button to increase and a "-" button to decrease the audio volume.
When I push a button I can see "Volume 22" on the display...

Or, if you want a rotary encoder anyway and you have a free analog input channel then use a normal potenciometer (Vcc,Gnd) and "scan" the position by reading the wiper voltage :)

:=Does anyone on this forum know of a good quality, not very expensive incremental encoder that might be suitable for front panel control replacement? I'm working on a project where I need to be able to preset from memory (e.g.) an audio level on a device , but also must allow the end user the ability to turn the level up or down from the preset value.
:=
:=I've looked on line at some Bourns devices, but from what I can tell, the affordable ones only generate 6 pulses/rotation. I need much finer resolution than that.
:=
:=Can anyone out there point me in a useful direction? Thanks.
:=
:=John Cutler</font>
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Original Post ID: 144515247

[R.J.Hamlett]

:=Does anyone on this forum know of a good quality, not very expensive incremental encoder that might be suitable for front panel control replacement? I'm working on a project where I need to be able to preset from memory (e.g.) an audio level on a device , but also must allow the end user the ability to turn the level up or down from the preset value.
:=
:=I've looked on line at some Bourns devices, but from what I can tell, the affordable ones only generate 6 pulses/rotation. I need much finer resolution than that.
:=
:=Can anyone out there point me in a useful direction? Thanks.
:=
:=John Cutler
If they develop 6 pulses/rev, this gives 24 'edges', which is not quite so bad. However generally optical encoders get more expensive with increasing resolution. The cheapest source normally, is a mouse. A lot of designs, use an IC for the sensor, which handles the quadrature decoding for you (giving a pulse train, and a 'direction' signal). Mice usually have a disk with between 60, and 90 fingers, giving 250 to 360 edges per revolution. A mouse for $10, gives two sensors, for far less than any of the commercial units. HP, do a family of shaft encoders, that are in standard 'potentiometer' cases, with between about 250, and 500 lines, giving 1000 to 2000 edges. Look for HEDS-5701. Generally it is cheaper and simpler on a microprocessor design, to use 'up/down' buttons, (with perhaps two rates, accelerating if the button is held for some time), and an indicator to show the value returned.

Best Wishes
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Original Post ID: 144515249

[john cutler]

Thanks for replying. I need to use a rotary encoder because I'm dealing with musicians, playing music in real time, who don't have time for up/down buttons, and who want to be able to grab a knob and turn it. Because I also need to preset levels from memory, remotely, I can't simply use a pot (unless motorized ) Unfortunately, I think I'm stuck with encoders.
I can't even get away with one encoder and an assign switch - the siuation calls for mimicking old fashioned multiple knobs.

Thanks.

John
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Original Post ID: 144515256

[ajt]

It may be less expensive to purchase an encoder based volume control. Oxmoor Corp. makes two such products: the RC-16 and Zon controls. http:\\www.oxmoor.com.

:=Does anyone on this forum know of a good quality, not very expensive incremental encoder that might be suitable for front panel control replacement? I'm working on a project where I need to be able to preset from memory (e.g.) an audio level on a device , but also must allow the end user the ability to turn the level up or down from the preset value.
:=
:=I've looked on line at some Bourns devices, but from what I can tell, the affordable ones only generate 6 pulses/rotation. I need much finer resolution than that.
:=
:=Can anyone out there point me in a useful direction? Thanks.
:=
:=John Cutler
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Original Post ID: 144515260
_________________
Al Testani

[R.J.Hamlett]

:=Thanks for replying. I need to use a rotary encoder because I'm dealing with musicians, playing music in real time, who don't have time for up/down buttons, and who want to be able to grab a knob and turn it. Because I also need to preset levels from memory, remotely, I can't simply use a pot (unless motorized <img src="http://www.ccsinfo.com/pix/forum/smile.gif" border="0">) Unfortunately, I think I'm stuck with encoders.
:=I can't even get away with one encoder and an assign switch - the siuation calls for mimicking old fashioned multiple knobs.
:=
:=Thanks.
:=
:=John
This doesn't explain your need for 'more steps'. The low accuracy encoders, are very commonly used for exactly this application. In most cases, these are used without 'end stops', so function like the roller selectors on mice, where you roll the encoder in one direction to increase a value, and the other to decrease it. Normally there is some physical feedback (such as the note/effect being audible), so that you can stop when the right effect is reached. You don't need any great accuracy to do this (it is common to implement an 'accelerate/decelerate' function based on how fast, or how far the encoder is moved). It is better to use a relatively 'low accuracy' device, with something like a spring bias to centre, rather than a high accuracy encoder (which makes the operation too fiddly). This approach is used on several of the existing commercial effect units.

Best Wishes
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Original Post ID: 144515261

[Kenny]

:=Thanks for replying. I need to use a rotary encoder because I'm dealing with musicians, playing music in real time, who don't have time for up/down buttons, and who want to be able to grab a knob and turn it. Because I also need to preset levels from memory, remotely, I can't simply use a pot (unless motorized <img src="http://www.ccsinfo.com/pix/forum/smile.gif" border="0">) Unfortunately, I think I'm stuck with encoders.
:=I can't even get away with one encoder and an assign switch - the siuation calls for mimicking old fashioned multiple knobs.
:=
:=Thanks.
:=
:=John

The March 2003 issue (No. 152) of Circuit Cellar has an article on using multiple encoders for just this situation. Downloadable code is for AVR but should be able to be ported to PIC. It uses the Philips i2c port expander PCF8574 for the encoders, the advantage being the interrupt on port change feature of these devices (as for port B of PICS). Multiple PCF8574 devices could be used for more inputs, thereby freeing up port pins on the PIC.

Regards
Kenny
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Original Post ID: 144515265

[john cutler]

:=It may be less expensive to purchase an encoder based volume control. Oxmoor Corp. makes two such products: the RC-16 and Zon controls. http:\\www.oxmoor.com.

Looks like hq stuff, but not at all what I need. I'm designing a stand alone system with many individual small remote controlled mixers, each needing at least 8 encoders - I ordered some cheapies from Bourns to try out.

Thanks for your help
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This message was ported from CCS's old forum
Original Post ID: 144515266

[john cutler]

:=The March 2003 issue (No. 152) of Circuit Cellar has an article on using multiple encoders for just this situation. Downloadable code is for AVR but should be able to be ported to PIC. It uses the Philips i2c port expander PCF8574 for the encoders, the advantage being the interrupt on port change feature of these devices (as for port B of PICS). Multiple PCF8574 devices could be used for more inputs, thereby freeing up port pins on the PIC.
:=
:=Regards
:=Kenny

Kenny: Thank you - very germane, helpful article. I ordered a few flavors of encoders to try out. I think this will put me on the path.

John
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Original Post ID: 144515268

[Will Reeve]

Hi,
I've used the Bourns 24 cycle encoder a lot in our products. It costs around 3 UKP. <a href="http://www.farnell.co.uk" TARGET="_blank">http://www.farnell.co.uk</a> order code 109-113 should get you some data. I have CCS C code which handles three of these connected to any combination of IO pins on a PIC16F873 if you get stuck!

Will
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Original Post ID: 144515285

[Tomi]

Hi John,
Here is an interesting link...

HTH,
Tomi

:=Thanks for replying. I need to use a rotary encoder because I'm dealing with musicians, playing music in real time, who don't have time for up/down buttons, and who want to be able to grab a knob and turn it. Because I also need to preset levels from memory, remotely, I can't simply use a pot (unless motorized <img src="http://www.ccsinfo.com/pix/forum/smile.gif" border="0">) Unfortunately, I think I'm stuck with encoders.
:=I can't even get away with one encoder and an assign switch - the siuation calls for mimicking old fashioned multiple knobs.
:=
:=Thanks.
:=
:=John
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This message was ported from CCS's old forum
Original Post ID: 144515290

[Sherpa Doug]

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Original Post ID: 144515301

[Shane Rowell]

US digital has some great devices. They also have some interface chips that are really good.

Shane

:=Does anyone on this forum know of a good quality, not very expensive incremental encoder that might be suitable for front panel control replacement? I'm working on a project where I need to be able to preset from memory (e.g.) an audio level on a device , but also must allow the end user the ability to turn the level up or down from the preset value.
:=
:=I've looked on line at some Bourns devices, but from what I can tell, the affordable ones only generate 6 pulses/rotation. I need much finer resolution than that.
:=
:=Can anyone out there point me in a useful direction? Thanks.
:=
:=John Cutler
___________________________
This message was ported from CCS's old forum
Original Post ID: 144515313