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midiphy SEQ v4+


latigid on
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  • 3 weeks later...
On 12/24/2019 at 3:30 AM, latigid on said:

 

  • Rear panel has a USB B port (power/data) for better mechanical strength
    • Switch for USB OTG host is provided but we notice some devices are incompatible

 

I hate to ask what may be a silly question, but how exactly does one make use of the two USB ports? I have not been able to find much documentation or discussion of the USB features. What sort of devices do work? I tried plugging my Korg nanoKey Studio into the A port while providing power via the B port, and the Korg didn’t turn on. Can I plug a synthesizer into the A port?

Thanks for any insights.

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Is the Korg self-powered? Did you jumper the +5V on the Core USB PCB? 

I don't have time to investigate at the moment but you may also look into the jumpers on the Waveshare board. Read up on OTG handshakes; it might be that certain pull-ups or other data routines are required.

https://www.waveshare.com/w/upload/5/58/CorexxxV-Schematic.pdf

Best,
Andy

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Hi Adam,

Everything works, unless it doesn't :innocent:. Yes, you should be able to use a controller keyboard and route the USB MIDI to another port for example.

Try here; in essence the hardware is the same, only the FET switch that senses current doesn't feature in the wCore/USB.

http://midibox.org/forums/topic/18906-usb-host-support-for-mbhp_core_stm32f4/#comment-165136

As noted, there are a few other jumper settings on the 407v breakout. I've read a few things in passing that require a different pull-up or so depending if the device is self-powered or not.

Have fun!
Andy

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  • 3 weeks later...

I finally found some time to revisit the USB port. Of course the most obvious explanation for my sequencer not powering the Korg controller was that I omitted the +5V jumper. I thought back a bit and realized that at the time I assembled the USB PCB (actually both times, since I had to do it twice) I was somewhat puzzled by the presence of that jumper. I mean, nobody has to open up their laptop computers to move jumpers to provide power to the USB ports, right? :-) So at the time I left the jumper off and decided to investigate it later.

I did a little reading before opening my sequencer's case. The first thing I learned is that USB hosts are required to supply +5V to downstream devices, so there doesn't seem to be any need for a jumper there. This led me to wonder about circuit protection; eventually I found this article which recommends specific overcurrent protection components for USB host ports. All it takes is one protection device in line with the power supply, and luckily that device happens to come in a 1206 SMD which spans the distance between two header pins on 0.1 inch centers.

I ordered some of them and soldered one across the jumper pins on my USB PCB. (I also figured out that the easiest way to get to that PCB is to take off the end plate of the case.) My sequencer now powers and recognizes my three Korg controllers (nanoKontrol 2, nanoKontrol Studio, and nanoKey Studio). To answer my own question, I'm pretty sure that the USB port won't work with either my Access Virus TI2 or my Novation MoroderNova, since both of these devices require special drivers on the host PC.

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  • 4 weeks later...

 

 

Another successful build. Thanks to all involved for such a great design and realization of this sequencer. I followed the build videos and that kept me on track. The only problem I had was of my own doing, mixing up the resistor networks then getting erratic output on the first seq_l test. Hot air and swapping the resistor networks around fixed this. Thanks to @Antichambre  for those great looking keycaps too. Looking forward to more great things from the Midibox team.

Edit: I did have the odd inversion of colors on the beat LED, I had red on measure green on beat, a change of values in the config file HWCFG fixed that.

SeqV4_Plus.jpg

Edited by slo
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On 12.3.2020 at 9:17 PM, slo said:

 

 

Another successful build. Thanks to all involved for such a great design and realization of this sequencer. I followed the build videos and that kept me on track. The only problem I had was of my own doing, mixing up the resistor networks then getting erratic output on the first seq_l test. Hot air and swapping the resistor networks around fixed this. Thanks to @Antichambre  for those great looking keycaps too. Looking forward to more great things from the Midibox team.

Edit: I did have the odd inversion of colors on the beat LED, I had red on measure green on beat, a change of values in the config file HWCFG fixed that.

SeqV4_Plus.jpg

i like the keycaps a lot :D

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24 minutes ago, Hawkeye said:

@slo great build, congrats! :cheers:

Regarding key cap alternatives to the clear ones on the standard builds, we might have something cooking in the lab, that could be introduced soon :).

:D yesss, can't wait.  after a while of usage i find it a little bright too.

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21 hours ago, rbv2 said:

:D yesss, can't wait.  after a while of usage i find it a little bright too.

Yess, me too! A while ago I bought a set of keycaps from Antichambre for my LoopA and I regret I didn't order them for the sequencer, these were the last spares...and I love them. Would be great if we could order them from the webshop. 

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3 hours ago, Elektruck said:

Yess, me too! A while ago I bought a set of keycaps from Antichambre for my LoopA and I regret I didn't order them for the sequencer, these were the last spares...and I love them. Would be great if we could order them from the webshop. 

It will have similar properties but will look slightly different - with one reason: it's optimized for a rather large and rather quadratic new product that is in the pipeline :), but i should probably better keep silent to not jinx things! :)

Many greets,
Peter

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  • 2 weeks later...

New keycap reveal at 1000 subs! :) Nah, ok, here they are! :)

c31c083fa57a5edba144252933df84bf.jpg

Hope you enjoy them, we think they look great on the white metal cases, and they do help a bit with "stray light removal". We'll soon update the SEQ v4+ kits to contain those, in the meantime every new SEQ v4+ kit order starting today can get a free update to these keycaps - they will be slightly more expensive due to increased manufacturing complexity. Made in the U.S.A.! :) Hope you enjoy!

Stay safe and many greets! Peter

 

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