Let`s go for my first midibox DIY - BLM

MIDIbox BLM
1

Hi everybody !

I think about built something for a long time… i don´t have news about SEQV4 Bulk, so i will start my first DIY midibox with the BLM. (I can´t wait more !)

I have a lot of idea maybe bad, maybe good and i need your help to do good thing at all.

First: Sorry for my bad english ! But i prefer to speak in english here (maybe also because the french forum is a bit too quiet ^^), and i hope i will improve my english !

First i draw a face plate for the BLM (i work with catia V5)

i will expose my vision of the BLM :

The face plate will be built by Schaeffer

For the switch i want to use the illumec 5G with green/red leds and a round frosted white caps ( i dont know if its the better way because it`s a bit expensive) but for me it seems be the easy way cause leds are integrate on them.

I don`t know if these buttons are noisy (click) or no, i think i prefer silent button.

I hesitate to do the button with cheapest buttons and a single rubber keypad ( i know what could be the price… and who could built it for personnal use and as a single or couple of part)

If you have ideas about that, explains me !

I want to do that with a Single pcb with all the buttons mounted on it. so i have to create this on progam (i never do this before so i have to learn a lot !)

Actually i try to understand something ; If the connections are the same on the midibox schema and the illumec schema

For me if i connect like that. that`s works, but maybe i have to add the blackled on the illumec to have the same working things. no ?

Secondary for the PCB do you know if it`s possible to do only one single fat PCB to put all the switch on it. Do you know that ?

That`s all for my question actually, but i will have a lotttttttt of question during this project !

I hope you could help me ! Bye

2

Good luck for your BLM project! How big did you want to make it?

One thing you should know is your choice of LED switch will NOT work with the current firmware.

---->|-----

          | ____

          |

---->|-----

or

---->|-----

____ |

    |

    ---->|-----

will work but

----|<-----

____| |____

    | |

    ---->|-----

will not work.

You need two distinct LEDs for this application, the third diagram shows two LEDs back to back; you can’t light both at once!

Edit: clarity

3

OK, after reading a lot and a lot of things about led and buttons here and there, i’m a little bit lost !

I think my first idea with illumec was really expensive so maybe i could do something better.

A lot of people speak about bicolor led but when i see the demo video of the BLM i can see 3 color : green, red and orange.

The orange is made with the green and the red leds activate at the same time ?

I’m thinking about the Livid or Sparkfun buttons and maybe also their switchs, but there is a problem :

For exemple : if i take this one : Buttons Sparkfun link

There is only one led and only green, so i have to change that by a bicolor led ? each time i search some bicolor leds they are like the bad thing you show to me :

----|<-----

____| |____

| |

---->|-----

Here is a solution for this thing ?

4

The orange is made with the green and the red leds activate at the same time ?

That’s right, which is why you need “3-leg” LEDs, with either a common cathode or anode. Sometimes they are even called “tri-color” (red/green/orange) but this term can also be confused with RGB LEDs (4-leg).

If you wanted to use pre-built tact switches, you could go for the Omron ones:

http://mouser.com/ProductDetail/Omron/B3W-9010-RG2N/?qs=sR392Zi6y%2f9CSJ7gat14GQ%3d%3d

but they are expensive!

I hope that doesn’t put you off; you may find a solution in the rubber buttons discussed elsewhere in this subforum.

5

ok, it’s not really important to have “pre-built” switch. After eading a lot of page; i will make the BLM with livid buttons.

If i have understand the thing with this kind of switch i don’t need to have buttons, only the PCB and the conductive ring on the bottom of the button is usefull ?

so i have to create a PCB like that but with 16x16+X contacts ?

blmscalar.png

For the leds :

this one could be fine ?

Tricolor LED

So maybe i could start to order and build soon !!

Thx a lot, Bye !!

6

Hi there,

good luck with your project!

Tri-color LEDs will not work due to the wiring (at least one color won´t be available) - have a look:

http://www.ucapps.de/mbhp/mbhp_blm_map.pdf

So use two single-color leds or duo-color leds with a shared cathode.

Greets,

Peter

7

Hi ! Thx a lot ! i´m really motivated so it will be fun !

For the led, the link i purpose was for a bicolor led with common cathode. so they have only 2 color per led but when they are activated at the same they create a third color. I think this LED is well. no ? If i watch the PCB Schema i can see 3 holes on the center of the contact so i think he use 3 legged LED, and when i watch the video about BLM i can see 3 color on it so i think i`m right.

For the contact on PCB someone could agree my opinion or maybe i´m lost for this kind of things ?

Thx a lot have a good day all !

8

Yes, you are absolutely right, these will work - I misunderstood the term “tri color” as three base colors (RGB), especially after looking at the price :slight_smile: As long as they have three leads with a common cathode, it will work for the BLM.

Please note, that you can get them @ reichelt for less than 20cents per piece, it is expensive to buy around 300 of them :slight_smile:

Greets and have lots of fun building it!

Peter

9

if you order them from a pcb factory, be sure to avoid HASL on the pcb contacts, it oxidizes rapidly and the switches will not work properly. bare copper is a similar problem. i had some success using a chemical plating product called cool-amp which is pretty good for diy pcbs. iirc the sparkfun silicone button pcbs use a silver surface. i think the best idea is to use ENIG or gold leaf on the contacts, but i lost interest in the sparkfun blm before testing this…

10

Hi everybody ! i have another question !

What is the black led on the schema ?

is this a resistor ? What are the specifications of this part ?

Thx a lot all bye and have a good evening !

11

Hi, it is a 1N4148 diode for the button input matrix :slight_smile:

12

Hi, this is a diode (non-light emitting). It needs to be placed here to stop multiple rows or columns of switches activating at the same time.

Again, bonne chance! Make sure you get somebody to check your PCB layout before you get anything manufactured.

Edit:

Either by posting here or on the user forum.

13

Hi everybody ! Are you fine ?

I have again a lot of question !

Before i will start to create the PCB (I will use Eagle and i actually learning and training on it ! it will be a long way to finish that :slight_smile: )

I need to do a part list for every thing i will use on the blm.

i started a list with all the part :

But i am totally lost on all the reference… these are too many for me, such as the 74HC module, resistor, condensator, transistor,…

Could someone help me to create a clean list ? maybe i have made some mistake so please help me !

So if you know, which part is clearly well and you have a reference, normally you can edit the part list !

Here is the PART LIST

After theses correction i could take all drawing for each parts, and start to create the PCB layout !

Thx a lot for all ! and be prepare for the weekend ! :frantics:

14

With regards to a BLM & BLM Scalar PCB. Find bhudda started a bunch of good work here (and already corrected his mistakes): http://www.midibox.org/dokuwiki/doku.php?id=findbuddha

I was working on a proper BLM Full PCB without the center gap based on his design I posted here: http://www.midibox.org/dokuwiki/doku.php?id=peterpressure

Your welcome to use those for your PCB design, we used KiCad and I want to help however I can because well, I want a BLM too!!!

:slight_smile:

15

Yeah !!!

Thanx for the link this will help me a lot ! i work on Eagle so it will be fun to have different way to modify it !

I want to use livid buttons so my PCB wil look different !

I have just some problems with select the good parts ! (See my post before)

I start to design the PCB yesterday and it will be a long way !

but i will use your design to know what is tht thickness of your traces, and some others things ! Thx !!

16

Hello,

First problem : i want to use livid contact but but they specify that you have to use the rectangular cantact for the small contact. The is that the 6legged LED can’t be inside this contact. i seen on wilba PCB that he use rounded contact but i want to be sure these contact will works !!!

a little picture to explains that :

Edit : Normally that`s ok, a member of the livid forum comfirm that ! :smiley:

17

Hey allo !

Do you know witch thickness and width i have to use on my trace omn the pcb ?

Also here is a standard for the mounting hole nad the trought hole (like ti put led or dil pin inside) ?

18

Hi !

i have still finish all the 16x16xX shematic on Eagle, but i have a little question

is that normal to haven’t connection on the 16 pin connector on the botton ( between the Y line switch) ???

On K1 and K2 and the pin 6 7 8 9 10 11 on my picture.

19

I haven’t checked the actual pins that you have left unconnected (should you have them labelled correctly to make error checking easier for yourself?), but it is normal to have pins unconnected for the +X row and column.

I’ve attached a pic of my schematic, different layout but same principle.

post-6793-0-42969600-1329040461.jpg
post-6793-0-42969600-1329040461.jpg976×725 144 KB

20

Hey; i give you some news :

I stop my work on the PCB for a moment because i didn’t know what are the dimensions of the contact on livid buttons !

I received my 2 first pad today ! (thx to Altitude on this forum \o/ ! Really nice )

So now i could draw a new contact on Eagle especially for the livid pad !

The contact dimensions :

Now i can continue my work ! see you next step ! Bye

(Sorry for the big size of my photo)