TK.

MIDIbox SEQ V4Lite

338 posts in this topic

Yes!

The gate length will be determined with the note duration that you are playing.

Play the note(s) short: short gatelength

Play the note(s) long: long gatelength

It isn't possible to modify the gatelength from the user interface, but you can just record the step again with the desired gatelength.

Best Regards, Thorsten.

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hello tk,

first a big thanx from berlin to your great diy project and the perfect instructions. i just finish my first soldering of my life, hoping that it will run... :rolleyes:

well normally it would be time to put the processor on the lpc core17- but for any reason a friend of mine and me ordered the wrong processor at wattenrot- it´s a 1200 not the needed ..69.

shit happens...

now we have two processor in stock. my question is, what you can construct else of the midibox projects or can they be reused for anything else of your projects??

a big thanx in advance 4 some inspirations. of course the original processor is ordered, hehehe

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Hello TK,

as you can imagine, I didn't have much time recently to make some music. After I came back from Lanzarote I did have a lot of things to do, like playing emergenca band contest, caring about my daughter and my new girlfriend and so on and so on.

Finally I found some time to test my SEQs. And here is a little bug report (FW 0.55): All of my three SEQs have the same symptoms: After a few minutes of playing the realtime-record-mode doesn't work anymore. You see notes beeing recorded and the next time the position indicator comes around the notes just get deleted instead of beeing played. With notes that are beeing recorded in step record mode that doesn't happen. When you switch into realtime-record-mode the recorded notes immideatley get deleted. Do you understand what I'm talking about? What could be the reason for that strange behaviour?

PS: I just updated all SEQs to 0.56 and that bug still exists.

Edited by cd_reloaded

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well normally it would be time to put the processor on the lpc core17- but for any reason a friend of mine and me ordered the wrong processor at wattenrot- it´s a 1200 not the needed ..69.

shit happens...

now we have two processor in stock. my question is, what you can construct else of the midibox projects or can they be reused for anything else of your projects??

a big thanx in advance 4 some inspirations. of course the original processor is ordered, hehehe

Unfortunately I don't see a way to run MIOS32 on LPC12xx based microcontrollers, because they only have 8k SRAM which isn't enough to run basic services.

There could be a way to hack an USB->MIDI interface, but again due to the small SRAM it wouldn't fit my personal robustness requirements. ;)

Maybe you are able to sell it on the (german) http://www.mikrocontroller.net/ forum

Hello TK,

Servus! :)

Finally I found some time to test my SEQs. And here is a little bug report (FW 0.55): All of my three SEQs have the same symptoms: After a few minutes of playing the realtime-record-mode doesn't work anymore. You see notes beeing recorded and the next time the position indicator comes around the notes just get deleted instead of beeing played. With notes that are beeing recorded in step record mode that doesn't happen. When you switch into realtime-record-mode the recorded notes immideatley get deleted. Do you understand what I'm talking about? What could be the reason for that strange behaviour?

I can't reproduce this. :-/

It could happen if an incoming note hangs (e.g. MIDI cable unplugged) - the note would erase all steps.

In order to check if this is true, could you please check if this also happens if another keyboard is connected (or if the MIDI cable of the keyboard is removed)?

If it doesn't happen anymore, we know into which direction the analysis has to be continued.

Best Regards, Thorsten.

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hello tk,

thank u 4 the information.have a sunny day.

best regards

aco

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Hello TK,

I tested and tested and I found out that this strange effect happens, when a lot of midi-information comes together. e.g. when recording controller events.

And I can imagine that your theory about the hanging Midi-Note couldbe the reason. My Jx3P and my DW8000 tend to have hanging notes from time to time.

I will keep on watching that.

Thanks

btw. I love the SEQs and there is a little chance that we play at the "Lange nacht der Musik" again. Its not sure yet, but maybe ....

Edited by cd_reloaded

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hi christian,

i think you have an old firmware. or you have to switch the in-out funktion off!

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hi christian,

i think you have an old firmware. or you have to switch the in-out funktion off!

Hi Cit,

I use the latest FW-Version. Maybe I should try to switch it off. I will continue testing ...

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You should have mentioned this special setup earlier!

The reason is clear: two MIDI IN ports are receiving more data than a single MIDI OUT port could sent, this results into a "bottleneck" problem.

A possible solution is to add a large, software based FIFO for the MIDI OUT ports.

I will add it this weekend, it was on the agenda anyhow :)

Best Regards, Thorsten.

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FIFO = :question:

Edited by cd_reloaded

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FIFO = :question:

I assume TK means a First In First Out buffer

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V4L.057 is available now:


MIDIboxSEQ V4L.057
~~~~~~~~~~~~~~~~~~

o improved MIDI OUT throughput
[/code]

Christian: could you please check if this relaxes the "bottleneck issue" with your setup?

Best Regards, Thorsten.

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Hello TK,

sure I will test it as soon as possible, but I doubt it will be possible before next weekend.-

Anyway thx. Im sure it will be a improvement anyway :drool:

I will let you know ....

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Hi!

Is there a way to integrate the AOUT Module into the SEQLite yet?

If yes, any idea where to get the chip for the AOUT_NG module, if not want to order the whole lot from the US for 50 bucks?

If not, when will it be ready? I'd really like to get it to run analogue gear.

Or should I make a Midi/CV converter, separately? Speed/tightness is in any case an (musical) issue for me!

Thanqus!

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@moloxbat: yes it's possible according to the website.

I have a question too about mounting the LEDs, does the long pin go left or right?

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Is there a way to integrate the AOUT Module into the SEQLite yet?

Yes:

- open MIOS Terminal

- mount the SD Card with the "msd on" command

- open the file "MBSEQ_GC.V4" with a text editor

- search for "CV_AOUT_Type", set the value to 3 for the AOUT_NG module

- save the file

- open the file "SESSIONS/DEF_V4L/MBSEQ_C.V4"

- search for "MIDI_DefaultPort", set the value to 128 for the AOUT port

- save the file

- unmount the SD Card

- reboot your MBSEQ V4L

-> done :)

If yes, any idea where to get the chip for the AOUT_NG module, if not want to order the whole lot from the US for 50 bucks?

Unfortunately you haven't mentioned where you are living, therefore I fear that I can't give you an individual hint where to buy a single chip.

Note that I'm planning to create a new "low cost" interface which will be based on an inexpensive but sufficient DAC from Microchip, which can be purchased at Reichelt.

It will only support two channel, but thats sufficient for most purposes.

I have a question too about mounting the LEDs, does the long pin go left or right?

According to the schematic: http://www.ucapps.de/midibox_seq/mbseq_lite_blm.pdf

"LED cathodes (short leg) at right side!"

This means in other words: LED anodes (long leg) at left side!

Best Regards, Thorsten.

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I just saw I can order from Farnell. It does say in the infopage! So I might order the AOUT_NG PCB then & thx for the detailed instructions!

You mean the AOUT_LC??

I haven't even finished to make the SeqLite Frontpanel. I do not recommend using a breadbord/veroboard. It is a lot of work that way.

So I only tried the Core Module and that works fine according to MIOS.

I am going to try the functioning box tomorrow ftft!

I also find the connector labeling a bit hard, once the sockets are soldered, the labels are disguised, luckily I made a photo. Are the "squares" ground?

Also, one more thing. Is the "data" for the AOUT converted from midi messages to CV or is it in a "rawer", faster format before conversion to voltage? If that makes a difference speed wise!?

m

Edited by moloxbat

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You mean the AOUT_LC??

no, a new AOUT module which is low-cost, but doesn't need so many resistors.

I also find the connector labeling a bit hard, once the sockets are soldered, the labels are disguised, luckily I made a photo. Are the "squares" ground?

Are you referring to the MBSEQV4L Frontpanel PCB?

Also, one more thing. Is the "data" for the AOUT converted from midi messages to CV or is it in a "rawer", faster format before conversion to voltage? If that makes a difference speed wise!?

Your question seems to be related to a big misunderstanding of MIDI.

MIDI itself is one of the most efficient protocols to control synthesizers, it's even faster than "modern" protocols like OSC due to the packed format which is required to improve the performance through slow transport layers.

If MIDI events are transferred via a serial interface (the common MIDI plug) at the standardized baudrate it's relatively slow (1000..1500 events per second)

If MIDI events are transferred via USB it's much faster than any other method (more than 100000 events per second)

Internally the MBSEQ V4 handles CV via MIDI events as well, but since the AOUT module can be accessed via a superfast SPI based interface, this happens in (almost) zero-time!

And if you access the AOUT module via USB-MIDI (just enable the forwarding function), you will notice extremely low latencies as well!

Best Regards, Thorsten.

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I'm having trouble flashing the MIOS bootloader. I tried previously with the big USB connector on the core PCB, now I'm using the mini USB on the LPC. I had already cut the trace on the LPC. When I bridge it the onboard LED starts flashing, in bursts of 2 flashes. I'm using an old windows XP laptop. When I connect the LPC Windows sees a new device and wants to install drivers, which I cancel. The problem is that the LPCXpresso software never finds the device to flash. Any idea what I could be doing wrong?

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If you never flashed the bootloader before, you have to do this through LPC-Link by connecting the USB connector to the mini USB socket. All connections between LPC Link and LPC1769 target must be available. If you want to 100% ensure that there is no unwanted side effect caused by the MBHP_CORE_LPC17 board connections, unplug the LPCxpresso from the board.

mbhp_core_lpc17_program6.jpg

The LPC Link drivers have to be installed as well - just follow the usual install procedure. Last weekend I tried this under WinXP in a VirtualBox on my Mac, and even there it's working.

Note that two drivers will be installed (the second driver once you are starting with flashing).

Once this has been done, you don't need the LPC Link anymore, and bootloader updates can be done via the big USB connector (and via MIDI) in future.

Best Regards, Thorsten.

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Thanks for the hints.. in the mean time I have solved it by installing the software on a modern computer. Now it boots fine slowly PWMing the onboard LED. Next thing is to try and get the whole thing seen by MIOS Studio

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I've been trying to get my head around the transpose function. I programmed a sequence in the key of E major, set the scale as major and base note as E. when I switch the transpose function on the only way I can get a I - IV - V change is by playing keys C - F - G on the keyboard. Am I missing something? I'd like to play E - A - B. Not being that familiar with hardware sequencers I'm hoping someone will enlighten me on this.

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The base note selection is nothing else than a transpose function.

By default it's assumed that a sequence has been entered in C key, accordingly with base note C you wouldn't transpose the notes, with C# they would be transposed by +1, etc.

If the sequence has been entered in E key, just select base note "C" to avoid transposing (I know that this naming might be confusing, but I don't know a better way)

Best Regards, Thorsten.

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OK... So I managed to flash the bootloader and upload the SEQ4L firmware. Initially I had similar issues as DSL_man (LED activity at LED 1-5 and 12-16, nothing between LED 6 and 11, and pin not mapped errors). Then I read TK's reply that jumper J_15S needs to be mounted to 5V (why? there is no LCD? also not mentioned anywhere in docs?). Now my LPCXpresso is totally dead, even if I remove it from the core and connect it through mini-USB, there's no light going on. Could it be fried by not having set the J_15S jumper?

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Just noticed that J15S is still not not documented at my website, I should add hints in the schematic and with a picture at the MBSEQV4L page to highlight this.

This jumper is required to supply the transistors on the MBSEQV4L frontpanel PCB - the LPCXPRESSO module shouldn't be fried if this jumper is missing.

even if I remove it from the core and connect it through mini-USB, there's no light going on

Just to doublecheck: did you bridge the cutted 3.3V line to power the LPC1769 standalone?

A possible reason why the LPCXPRESSO doesn't boot when J15S connected: maybe a wrong J15 connection?

Does it boot when J15 is disconnected from the frontpanel PCB?

Best Regards, Thorsten.

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