Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 10 of 10

Thread: Custom Midi Controller

  1. #1
    Junior Member
    Join Date
    Jun 2013
    Posts
    2

    Custom Midi Controller

    I will probably purchase the Teensy 3.0 and use the CD4067BE chip. A fellow(fuzzy wobble) who built a custom MIDI controller that I am modeling mine after somewhat said to add because it "easily adds 16 analog input to your board. The four red wired linked between the Teensy++ and CD4067BE allow the Teensy++ to tell the CD4067BE which of the 16 pins it wants to read. The brown then sends the information for that analog input from the CD4067BE to the Teensy++. So if you require eight analog inputs or less, you will not need to add the CD4067BE to your PCB."

    For some reason I feel like this won't add any more inputs to my teensy 3.0, but if it does I would be glad to know if you could tell me. Also if I am using 16 rotary encoders, will I be able to include LED's? The kind of setup with my LED's are similar to the photo I will attach. I do not need to control the LED, I just want it to light up underneath the encoder like in the picture.Click image for larger version. 

Name:	MIDI Lights.jpg 
Views:	439 
Size:	42.1 KB 
ID:	604Click image for larger version. 

Name:	MIDI Lights.jpg 
Views:	439 
Size:	42.1 KB 
ID:	604Click image for larger version. 

Name:	MIDI Lights 2.jpg 
Views:	1167 
Size:	58.8 KB 
ID:	605

    Thank you very much on the input you have given/will give.Also I decided I will only have 8 encoders and 8 pots for variation, but I am still curious as to what adding the CD4067BE chip will do on the Teensy 3.0. There are very few who I can ask so I appreciate the help so if someone could recommend some LED's (and wether they should be horizontal or surface mount) to give me the kind of display in the pictures that would be great..
    Last edited by chief_flex; 06-20-2013 at 07:43 PM. Reason: more refined

  2. #2
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    20,171
    Quote Originally Posted by chief_flex View Post
    For some reason I feel like this won't add any more inputs to my teensy 3.0, but if it [CD4067BE chip] does I would be glad to know if you could tell me.
    You can use that circuit with either Teensy2 or Teensy3.

    If you power the CD4067BE from 5 volts, you might need 3 to 5 volt buffers (like a 74HCT245 chip) for the control signals. The CD4067 may not work reliably with only 3 volt signals when it's powered from 5 volts. If you power it from 3.3 volts, it should work fine with the 4 control signals connected directly.

    Also if I am using 16 rotary encoders,
    Usually an encoder needs 2 pins. Teensy3 has a total of 34 pins, with 24 easily accessible on the edges and 10 more not-as-easily accessible on pads on the bottom side.

    After you connect 32 wires for those encoders, you'll have only 2 pins left. The CD4067 chip needs at least 5 pins, 1 analog input and 4 digital outputs to control it.

    will I be able to include LED's? The kind of setup with my LED's are similar to the photo I will attach. I do not need to control the LED, I just want it to light up underneath the encoder like in the picture.
    Since the LEDs don't connect to Teensy in any way, using Teensy doesn't impose any limitations.

    However, you should consider the amount of power those LEDs will require. If you want the entire device to be powered by the USB, it's best to keep the total current under 100 mA for compatibility with low-power USB (mainly unpowered hubs). Teensy 3.0 uses about 27 mA, and you'll probably need about 0.5 mA in the pullups for each encoder, so a good plan would keep all the LEDs under 65 mA total.

    High power USB ports can provide 500 mA of current, so if you never use it with low-power USB ports, you can use quite a bit more power.

  3. #3
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    20,171
    Also, I'm a bit curious where you can buy light-up knobs and rotary encoders that let light pass through.

    I have a big box of old knobs, all black plastic, and a small collection of encoders, but they all have bodies large enough right behind the panel that it would seem impossible to do this kind of lighting. Obviously it is possible from those awesome photos. I've never seen such encoders and knobs for sale, so I hope you'll post a link or info where buy buy them?

  4. #4
    Junior Member
    Join Date
    Jun 2013
    Posts
    2

    wowza

    Quote Originally Posted by PaulStoffregen View Post
    Also, I'm a bit curious where you can buy light-up knobs and rotary encoders that let light pass through.

    I have a big box of old knobs, all black plastic, and a small collection of encoders, but they all have bodies large enough right behind the panel that it would seem impossible to do this kind of lighting. Obviously it is possible from those awesome photos. I've never seen such encoders and knobs for sale, so I hope you'll post a link or info where buy buy them?
    Click image for larger version. 

Name:	Encoder knob Albs DK16-190V3.jpg 
Views:	4303 
Size:	81.7 KB 
ID:	607 These are the kinds I am looking for in encoders while I want these for my pots Click image for larger version. 

Name:	Clear pot caps.jpg 
Views:	269 
Size:	46.0 KB 
ID:	608. The pot caps are purchasable, but I do not know how to purchase the awesome encoder kind. I saw forums requiring you to join a mass order but it has already occurred and I am wanting those so badly or to even make some myself. This is my first project of any kind and so I am willing but not knowing :P.

  5. #5
    Senior Member
    Join Date
    Nov 2012
    Location
    Boston, MA, USA
    Posts
    1,106
    TE connectivity make them, for example
    Type DPL12 Series 12mm Rotary Encoder with LED

    Farnell used to stock them but no longer do.
    Last edited by Nantonos; 06-21-2013 at 08:53 AM.

  6. #6

    What controller is that in the pictures?

    What controller is that I the pictures? I'm trying to find potentiometer knobs that have translucent indicators like shown in the pictures the ones with the blue led back lighting

    Cheers

  7. #7
    Member
    Join Date
    Jun 2016
    Location
    rural West Virginia
    Posts
    55
    I got my RGB LED encoders from Sparkfun. They have a small clear plastic knob that goes with it. They are not bright enough to see outdoors but work good in a dimly lit room. https://www.sparkfun.com/products/10982

    Mouser has these, but at $6 each, I haven't tried them. http://www.mouser.com/ds/2/54/EL12T-777462.pdf

    You can use a port expander from Maxim or Microchip to control LED's via SPI. As described a multiplexer chip (I use a 74LV4051) can be used to add ANALOG inputs. I have not found a reliable way to multiplex rotary encoders yet, so it still takes two pins per encoder, 3 if you use the pushbutton function.

    Bitches Love My Switches has tons of knobs cheap including those clear ones in post #4. http://www.bitcheslovemyswitches.com...egory=15000062

    The Tyco encoder mentioned above is sold at Allied Electronics, but cost more than the Bourns part, and only has a 1 or 2 color LED. http://www.alliedelec.com/search/res...spx?term=dpl12
    Last edited by tubelab.com; 03-02-2017 at 01:45 AM.

  8. #8
    Thanks Tubelab

    Specifically I'm looking for some thing like the black and white knob below but where the light from the potentiometer is translated from the pot shaft into the knob's indicator (in this example it's solid white which won't let the light through but. It might be an illusion from the photography but the blue and white knob caps from the photos in the O.P's post look like they let the light through what appears to be the blue translucent/clear plastic of the indicator. I'd like to know where they were sourced from or at least which manufacturer makes that control surface?

    Click image for larger version. 

Name:	IMG_1640.jpg 
Views:	92 
Size:	39.3 KB 
ID:	9875Click image for larger version. 

Name:	IMG_1641.jpg 
Views:	87 
Size:	76.2 KB 
ID:	9876

    Any idea who makes them or makes something similar?

    Cheers

  9. #9
    Member
    Join Date
    Jun 2016
    Location
    rural West Virginia
    Posts
    55
    I haven't seen anything like those, but I tend to look for low $$$ options since I'm rather budget constrained right now and my synth currently has 53 knobs on it, with more in the works. The pots are the most expensive thing in the synth followed closely by the knobs. I am building a modular system of my own design. First I will make it all work, then I will make it look pretty / flashy. That should be the first priority in most any project, unless you have a high probability of first time success.

    I got two of the RGB encoders and knobs from Sparkfun to see how well they worked, but decided against dropping a few hundred bucks on them for flashy looks right now. They still might make it into a guitar project that only needs a few knobs though.

    The picture shown in the first and eighth posts looks like a mixing board or console. These are usually rather pricey products with a limited production volume (thousands made, not millions). It is entirely possible that the knobs are made in house by the console manufacturer, or speced out to a plastics house, and not available to the public. I come from a 41 year career in an electronics manufacturing plant, and we did both. The low volume plastics were done in house, the high volume stuff like cell phone housings were done by a plastics company.

  10. #10
    Thanks Tubelab

    I've just realised it's from a Korg Zero 8. So yeah most likely won't be able to find them anywhere

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •