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MixPre-10T Rec/Stop button (failed)

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Mixpre-10T's  joystick controller often deviate.
and it cannot be record and stop at appropriate timing.


Other day,I found some arcade game button and lever sold at video game shop.
https://translate.google.com/translate?sl=ja&tl=en&js=y&prev=_t&hl=ja&ie=UTF-8&u=https%3A%2F%2Fwww.tops-game.jp%2Fproducts%2Flist.php%3Fcategory_id%3D115&edit-text=&act=url

and I tried to build HID button with adafruit trinket.

trinketbutton.png


ezgif-1-b05f5ae18b.gif
Working so far so good in Windows and Macintosh.
Although it is recognized as a generic HID device in Computers.
But did not work with MixPre-10T.

Seems there is USB-Host compatibility problem in Trinket.
http://translate.google.com/translate?hl=ja&sl=ja&tl=en&u=https%3A%2F%2Fwww.switch-science.com%2Fcatalog%2F1501%2F

I was disappointed just because I liked his compactness.

I will try another board in the near.

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Mixpre-10T's  joystick controller often deviate.
and it cannot be record and stop at appropriate timing.

Other day,I found some arcade game button and lever sold at video game shop.
https://translate.google.com/translate?sl=ja&tl=en&js=y&prev=_t&hl=ja&ie=UTF-8&u=https%3A%2F%2Fwww.tops-game.jp%2Fproducts%2Flist.php%3Fcategory_id%3D115&edit-text=&act=url

and I tried to build HID button with adafruit trinket.
trinketbutton.png.9622eb7b16b6420eb7fdb29b1fcd4b18.png


ezgif-1-b05f5ae18b.gif.7cfdccc8718dbcf3075f491c9d2262b1.gif
Working so far so good in Windows and Macintosh.
Although it is recognized as a generic HID device in Computers.
But did not work with MixPre-10T.

Seems there is USB-Host compatibility problem in Trinket.
http://translate.google.com/translate?hl=ja&sl=ja&tl=en&u=https%3A%2F%2Fwww.switch-science.com%2Fcatalog%2F1501%2F
I was disappointed just because I liked his compactness.

I will try another board in the near.
Ah, seems like a fun idea! Didn't see the second button at first so I was a bit confused. Will you keep it in a cart setup or in a bag?

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50 minutes ago, Jacob Gustavsson said:
On 2018/4/12 at 9:01 AM, INARI said:
Mixpre-10T's  joystick controller often deviate.
and it cannot be record and stop at appropriate timing.

Other day,I found some arcade game button and lever sold at video game shop.
https://translate.google.com/translate?sl=ja&tl=en&js=y&prev=_t&hl=ja&ie=UTF-8&u=https%3A%2F%2Fwww.tops-game.jp%2Fproducts%2Flist.php%3Fcategory_id%3D115&edit-text=&act=url

and I tried to build HID button with adafruit trinket.
trinketbutton.png.9622eb7b16b6420eb7fdb29b1fcd4b18.png


ezgif-1-b05f5ae18b.gif.7cfdccc8718dbcf3075f491c9d2262b1.gif
Working so far so good in Windows and Macintosh.
Although it is recognized as a generic HID device in Computers.
But did not work with MixPre-10T.

Seems there is USB-Host compatibility problem in Trinket.
http://translate.google.com/translate?hl=ja&sl=ja&tl=en&u=https%3A%2F%2Fwww.switch-science.com%2Fcatalog%2F1501%2F
I was disappointed just because I liked his compactness.

I will try another board in the near.

Ah, seems like a fun idea! Didn't see the second button at first so I was a bit confused. Will you keep it in a cart setup or in a bag?

Yes,

I'm going to put it in my bag.


It didn't work with Mixpre-10T.
However, as long as it is used with computer, this is sufficiently reliable.

Dials and bending sensors etc. are also sold in the catalog.
So I want to build controllers using them.

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 @INARI, I tried the same thing using an Adafruit ItsyBitsy (which has a proper USB implementation) and had the same issue. The problem is that the MixPre is using a strange USB descriptor for the HID interface, which they won't disclose. I corresponded with someone that writes USB libraries for Arduino and we couldn't get the MixPre to acknowledge the chip.

 

I have another approach, which I'll be writing about soon…

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12 hours ago, Allen Rowand said:

 @INARI, I tried the same thing using an Adafruit ItsyBitsy (which has a proper USB implementation) and had the same issue. The problem is that the MixPre is using a strange USB descriptor for the HID interface, which they won't disclose. I corresponded with someone that writes USB libraries for Arduino and we couldn't get the MixPre to acknowledge the chip.

 

I have another approach, which I'll be writing about soon…


Thanks!!
I gave up on this midway.
It seems that mixpre has such a tricky specification.

by the way, I found a pic that is MixPre-10T disassembled.

https://fccid.io/2AKLX-739M10T/Internal-Photos/Internal-Photos-3635481

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20 hours ago, Hugh Palmer said:

Good to see they're still doing some subliminal messaging on their boards! 

Screenshot_20180907-214614.png

 

yay! it's cool.

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Pity they don't disclose it. If I have time I can try hooking a keyboard to my MixPre and snoop with the oscilloscope. 

 

Do your devices implement a complete keyboard emulation? Perusing the HID specifications, keyboards are more complex than they seem!

 

Why don't you enable debugging in your program and check which requests is the MixPre sending to your unit? I guess it's failing to answer to some keyboard/HID description or status packets, probably it would be simple to forge a proper answer. 

 

I'll see if I can hook a DSO to a real keyboard connected to my MixPre and decode the USB exchange with Sigrok.

 

 

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1 hour ago, INARI said:

Thanks.
I don't have a USB analyzer, but I found a cheap one so I will try it.

 

Maybe it's enough to add debugging code to your device. I imagine (but it's just an educated guess) that the software you are using is supporting just the bare minimum subset of the HID/keyboard commands and the MixPre is using the whole set of commands a standard keyboard should support. 

 

So, probably either it's not answering some important message or it's sending the wrong answer. 

 

I would check the program and add a handler for unprocessed USB requests just in case. That should give a good hint of what's going on.

 

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I've uploaded bus probes of a keyboard that works with my MixPre 6, as well as a Teensy LC microcontroller programmed as a HID keyboard. The Teensy worked as expected with my computer but not the MP6. I decided to stop banging my head against the wall since I couldn't get usable info from Sound Devices and went down a different road as discussed here: http://jwsoundgroup.net/index.php?/topic/32035-mixpre-6lanc-remote-control-project/. That might work to my advantage with the upcoming v3 firmware- if the USB controller support includes the transport keys, I could put relays across the record and stop buttons on a NanoKontrol2 and have remote transport control via my design as well as faders and encoders.

 

USB Bus Probe KB.txt

USB Bus Probe Teensy.txt

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6 hours ago, borjam said:

 

Maybe it's enough to add debugging code to your device. I imagine (but it's just an educated guess) that the software you are using is supporting just the bare minimum subset of the HID/keyboard commands and the MixPre is using the whole set of commands a standard keyboard should support. 

 

So, probably either it's not answering some important message or it's sending the wrong answer. 

 

I would check the program and add a handler for unprocessed USB requests just in case. That should give a good hint of what's going on.

 

Thanks a lot!
I will dig a bit deeper it.

 

1 hour ago, Allen Rowand said:

I've uploaded bus probes of a keyboard that works with my MixPre 6, as well as a Teensy LC microcontroller programmed as a HID keyboard. The Teensy worked as expected with my computer but not the MP6. I decided to stop banging my head against the wall since I couldn't get usable info from Sound Devices and went down a different road as discussed here: http://jwsoundgroup.net/index.php?/topic/32035-mixpre-6lanc-remote-control-project/. That might work to my advantage with the upcoming v3 firmware- if the USB controller support includes the transport keys, I could put relays across the record and stop buttons on a NanoKontrol2 and have remote transport control via my design as well as faders and encoders.

 

USB Bus Probe KB.txt

USB Bus Probe Teensy.txt


Thanks a lot!
Anyway, I will observe what Nanokontrol sending when I recieve analyzer.

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