TK.

MIDIbox SEQ V4Lite

341 posts in this topic

A CME Z-KEY 49 seems to be nice for this purpose:

CME-Z-Key-49.jpg

This isn't a cheap solution (ca. 230 EUR @Thomann), but it has an aluminum case and plenty of space at the right side as if the designers considered the needs of the DIY folks ;)

Best Regards, Thorsten.

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Very cool idea!

The PCB will be much smaller than the prototype.

@ Thorsten: I will be working on the pcb on sundy night. I've got my new Mac. And it works perfecly and its about time to continue that project ....

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This is the version I knocked up,the buttons are 6mm acrylic rod with a slot milled in them to take the led's.

I am just waiting for some parts from reichelt at the the moment and experimenting with labeling.

post-7091-0-51912400-1317564903_thumb.jp

cheers

Paul

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This isn't a cheap solution (ca. 230 EUR @Thomann), but it has an aluminum case and plenty of space at the right side as if the designers considered the needs of the DIY folks ;)

There is a downside: You'd have to make your own power connection as it is fully USB powered. That could be tricky.

Another idea would be a Doepfer solution: Fatar keyboard (e.g. 49TP9) + MKE + cables.

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Huh? :no:

Why? :wacko:

More precise: There is a USB connector on the LPC17 Core board, as you can see on the first picture of this thread.

You can use this conection for power supply of the SEQ. If you don't like that you can use a normal external power supply instead.

The LPC17 core offers you the possibility you want.

As you see on the prototype picture. We use USB as the power connection.

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As you see on the prototype picture. We use USB as the power connection.

Not sure if you have considered power requirements here? If all 64 LEDs are on, and you use standard ones, you'll end up at 64 x 20mA = 1.28A, which is way above the 500mA max. current draw specified for USB devices. And that does not include the core MCU or other ICs. Of course, it's highly unrealistic that all LEDs will be on at the same time, plus you could use low-power LEDs. So, it's not completely impossible to USB-power this thing, I guess. Just make sure you know what you're doing here, i.e. do the math!

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There is a downside: You'd have to make your own power connection as it is fully USB powered. That could be tricky.

The preferred option is to power the core module via USB as well instead of using an external PSU.

You can even do this when the sequencer isn't connected to a computer, just us an USB hub like this one: http://www.reichelt.de/USB-Hubs/MAXXTRO-MX-UAP/index.html?;ACTION=3;LA=2;ARTICLE=99781;GROUPID=4831;SID=11TVLbZ38AAAIAAG9MIgIec1e46ae3eb4fc2fe4e011f269170227

I like it because it has a power switch; all my core modules (including MBSEQ V4) are supplied by the PSU of this hub.

Another idea would be a Doepfer solution: Fatar keyboard (e.g. 49TP9) + MKE + cables.

Nice idea! Instead of using a MKE, the core module could scan the keys via DIN registers :)

Not sure if you have considered power requirements here? If all 64 LEDs are on, and you use standard ones, you'll end up at 64 x 20mA = 1.28A, which is way above the 500mA max. current draw specified for USB devices. And that does not include the core MCU or other ICs. Of course, it's highly unrealistic that all LEDs will be on at the same time, plus you could use low-power LEDs. So, it's not completely impossible to USB-power this thing, I guess. Just make sure you know what you're doing here, i.e. do the math!

Measuring results are 200 mA when 220 Ohm resistors are used for the LEDs!

With 100 Ohm resistors (as recommended in the schematic) I expect ca. 250 mA maximum.

We are using common LEDs, no low-power variants. But they are time multiplexed and not completely saturated ((3.3V-1.8V)/100 Ohm = 15 mA, 15 mA * 8 = 120 mA)

Best Regards, Thorsten.

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The control surface PCB is up & running - no errors!

Great work, Christian! :)

And thanks to Nils for reviewing the design!

gallery_3436_129_56762.jpg

Under the hood:

gallery_3436_129_50899.jpg

sammichSID's new friend:

gallery_3436_129_317.jpg

Dimensions are matching:

gallery_3436_129_34279.jpg

Now it's time to finish the case! :)

Best Regards, Thorsten.

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Hi Thorsten,

As already asked in the gallery...are you thinking to a Ponoko case for it?

Regards

Antonio

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Yesyesyes! Looks very clean! Nice colour. I'm really looking forward to having my PCBs in my hands and to get that thing running.

Yes, there will be something like a ponoko-case. The Illustrator eps File is already existng. But I plan to built a very simplified case. with no sides, just the front- and the backside made of transparent acrylic material. I will post the file for download as soon as I have my pcbs to judge if everything s alright. If you want to do any modifications on the EPS-File, feel free to do so. I will only do what it thin is needed to fulfill my needs. It will look similar to a little tool I built a few years ago. I will post a picture of it later since I'm in a hurry now ...

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Nice Work!!!

I was little irritated by the Silver PCB, thought for a moment the parts were soldered to the (Metal)Frontpanel :whistle:

Is someone planning on a Bulk Order for the PCB's?

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Is someone planning on a Bulk Order for the PCB's?

That's very likely.

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Hiya,

I have my v4 light built up now with the lpc1769 working and mios 32 opsys recognised in mios 32 studio,what I am struggling with is downloading the v4seq lite firmware from the repository.

It seems I am downloading an empty folder?

So.....can anyone point me to the correct file for download please?

many thanks

Paul

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Hi Paul,

just checked it - works for me - all sources there and builds fine (edit: for STM32)... maybe re-checkout via svn?

Greets,

Peter

Edited by Hawkeye

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Hiya,

Hawkeye thanks for the reply but I am just out of my depth with the programming side of things....(always been a bit thick).....I don't understand this bit......."maybe re-checkout via svn".

Any chance of a nudge in the right direction?

cheers

Paul

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Hi Paul,

I haven´t found any downloadable binary versions of the seq lite on ucapps.de, so I assumed, that you checked out the source codes from the repository and built it by yourself...

If you need it, just drop a line and i´ll send you the current compiled version for LPC17...

Greets,

Peter

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Well sorry, I was too fast promising things, that I cannot keep ... when building the ´lite for lpc1769, it says

section .bss will not fit in region RAM

region RAM overflowed by 11344 bytes

I know as of this post

that it is possible to send certain big arrays to other ram segments... how have you guys already using/testing it built it?

Greets,

Peter

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I guess that you forgot to set the MIOS32_FAMILY string correctly, because it controls the memory allocation method for large arrays.

The release.sh script perfectly demonstrates the correct settings - you could also use it to build a proper release with correctly set variables.

However, I will release a first public version this evening together with MBSEQV4

Best Regards, Thorsten.

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The first public release V4L.052 is now available in the MIOS32 Download section.

Next weekend I will have some time to write the documentation and to publish some samples (I already prepared some)

The application is running pretty stable and I already had a lot of fun with it!

E.g. yesterday I was trying it with a Vintage Synth (Prophet5) and Korg Electribe from a friend and immediately got some nice sequences that we never heard before! :)

An important note: if no SD Card is connected, the application will hang for the first 5 seconds (to search for the SD Card)

Once a SD Card is connected the first time, a directory will be created under /SESSIONS/DEF_V4L and pattern banks will be generated.

This takes some seconds (ca. 20..30 seconds depending on the performance of your SD Card) - the LEDs will show a status bar, and the MIOS Terminal will show some messages.

Please don't switch off the MIDIbox until this process is finished.

Once the default session has been created, your MBSEQV4L will be available immediately ca. 1 second after power-on, considered that the "fastboot" option has been enabled in MIOS32 Bootloader.

Another important note: most MIDI Fx only work well with Force-To-Scale enabled.

Press & Hold the Scale button to select the scale (e.g. SCALE+#8 for Pentatonic Major), thereafter release the Scale button to select the root node (e.g. #1 for C, #2 for C#2, #3 for D, etc...)

This will be properly documented under http://www.ucapps.de/midibox_seq_lite.html of course! ;-)

Best Regards, Thorsten.

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Hiya,

My cs for the v4lite looks okay................pity it doesn't work..lol.

Just a few questions before I start dismantling it,I have used the following parts .....................

C9 is polybox instead of ceramic (on the lpc core)

SN 74HC595N (on the lpc core)

SN 74HCT541N (on the lpc core)

I believe the SN prefix is the manufacturer and the N suffix is the package style. (on the above chips)

Also I am still waiting for my sd card being delivered,will the v4l work without it?

cheers

Paul

Edited by taximan

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