Jump to content

Scan Matrix with D9 buttons : hazardous behaviour


Recommended Posts

hello all

I have designed a board for the scan matrix created by bill and thorsten but for D9 (or KSA) buttons, not for the c64 keyboard. It is based on the schematic of TK (one diode for one button).

I have checked the lines, electrical circuits are goods, connections are right. Application in the PIC is scan matrix v1 or v2 (same behaviour) and mios 1.9e.

BUT if I let the frontpanel in the normal position (mean buttons looking the sky) and if I shake the board , it produces random note on and note off, event X on not always followed by the event X off.

If I return the board (mean button looking the ground) this erratic behaviour disappears, and the device works perfectly well.

So I have though to a mechanical problem the buttons are the classical D9 (or D6), maybe to poor quality for a so fast scanning (no real spring inside, but a shitty system using a coin an folded edges).

So here are my questions :

1/ did someone tried such a panel ?

2/ I noticed there was not the possibility of using DebounceSet with the matrix. Am I right ?

I will try with better buttons in 2 days (KSA), and let a feedback. If this corrects the problem, the PCB will be published.

Cheers

Photo049_thumb.jpg

Photo050_thumb.jpg

Photo052_thumb.jpg

1399_Photo049_jpg2bff74359973237562e1394

1401_Photo050_jpgd9eaca6d6b224a690c75ef6

1403_Photo052_jpg77e3eaecd3bc76f1f97780f

Link to comment
Share on other sites

Thats strange, your buttons are looking similar to my own (DT6 from reichelt), and I never noticed such problems.

I don't think that a debouncing function would help here. Debouncing is used to filter transients after an event has been sampled, but the initial event will always be forwarded to the application.

Let us know how the other buttons are working

Best Regards, Thorsten.

Link to comment
Share on other sites

Hello Thorsten

thanks for a so fast answer

apparently, you have done a such panel. Did you use veroboard ?

Is there a possibility of using capacitors closed to the buttons ?

I repeat : the realy strange thing is that this panel works perfectly well if I return it , I mean if I use it with the buttons faced to the ground. That's why I had though to a mechanical problem, especially that these buttons were in destock in a supply store.

I will check one more time the connection to DIN and DOUT tomorrow. But for me button quality is engaged ...

Link to comment
Share on other sites

problem solved !

buttons weres defective. exchange with KSA works (but I had to fold them, cause hasn't the same size than D9), pin compatible.

soon : the PCB, but I have to add info like col/row number for buttons and C0-R0 for connecting, and front/back side.

But have also a look at monome.org, they now free release the monome40h PCB !!! really easy to make, just double sided. Firmware published too.

Thanks for help.

Photo060_thumb.jpg

Photo062_thumb.jpg

Photo058_thumb.jpg

1415_Photo060_jpgf437378309e4f0ff585e0d6

1417_Photo062_jpg6d77f3924a9bacb4e6c4902

1419_Photo058_jpg9b1926c3bdf7a65df238baf

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...