TK.

Revised 25-pin breakout port

83 posts in this topic

My boards showed up today as well, thanks! Now for some soldering :)

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thanks blingy

 

pm send

 

christoph

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My run has arrived from osh park, if I have your address expect an invoice soon.

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Looks like USPS considers it a parcel so each pair will actually cost $6 in shipping. Apologies for the incorrect estimate.

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All the boards are shipped except one pair and I talked to that person. If you paid they're on their way.

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done.

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PCB's arrived, thanks again

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Got mine, thanks a bunch!

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thanks!

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Do any EU Midiboxers have any known sources of 25 pin cables where the pins are connected 1-to-1? I've bought 2 cables now here in Czech and both of them only have 6/7 pins connected to do parallel printer connections. To get these line drivers working I need all 25 pins connected, and I'm lazy to DIY this, for once :)

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This one should work: http://www.reichelt.de/AK-450/3/index.html?&ACTION=3&LA=446&ARTICLE=4012&artnr=AK+450&SEARCH=AK+450

 

Btw.: is it only me, or do you guys also have the impression that prices increased in the last weeks?

E.g. my favorite turkish fast food restaurant recently increased the price for a Doner Kebab from 3.50 EUR to 4.50 EUR

And now I notice that Reichelt increased the price for this cable from 3.50 EUR to 4.50 EUR as well! ;-)

 

Best Regards, Thorsten.

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TK, Rowan,

thanks for the tips!

 

Btw.: is it only me, or do you guys also have the impression that prices increased in the last weeks?

 

Yeah I noticed, shame wages aren't doing the same ;-)

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I am thinking of starting a new bulk production run of the PCBs. If you're interested, pls. check out my post in Bulk Order Section (in order to keep this thread focusing on the module itself):

 

 

Thanks

arnonym

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Here is an issue I have came across with the MBHP Line Driver/Receiver and a proposed solution.

When using the Line Driver/Reciver with a MBSEQ To connect to one of Illiminator's 16x4 BLM and TPD the contrast of the MBSEQ is reduced. I'm guessing this is caused by the increased current drawn by all the extra LEDs on the BLM and TPD.

My proposed solution is to add a jumper that allows the 5v remote supply to be disconnected and a local 5v supply to be connected to the reciver board.

Edited by Rowan

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Ooof.. this means that the complete documentation has to be overworked (pictures, etc.)

Any other people request this extension?

 

Best Regards, Thorsten.

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I currently have only one Ilmenator's TPD attached to RX PCB after 3m of cable.

 

At TPD PCB I have a voltage of 4,35V, but it still works as expected. On TX PCB (before 3m cable) I have 4,6V, so already some drop from USB input over all the PCBs and cables in the main SEQ assembly. And voltage drop over 3m cable and RX PCB is 250mV.

 

Rowan: Do you mean your display contrast is reduced? Or the brightness of LEDs is less? All of them or only on remote PCBs? How are your levels of voltage on main / remote PCBs?

 

Generally, the suggestion from Rowan is worth thinking about - and maybe necessary for bigger remote installations, but from my side I did not see any issues with the current solution and maybe there's a different solution possible without changing all the documentation.

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The contrast of the display is reduced.

I haven't mesured the voltage drop but my instinct tells me it's caused the increase in current drawn by all the extra LEDs on the BLM and TPD.

I guess a workaround would be disconnect pin 12 (if I remember correctly) on the DB25 connector that feeds the 5v supply on the transmitter board then power the receiver end somehow. This would not be overly difficulty to achieve.

I don't feel this is a show stopper, just a potential issue that should be raised.

The other solution would be to use a power supple at the transmitter end that can provide more current which would be far easier though not always practical.

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If the contrast of the display is reduced, then the power supply is very likely at its end :-)

 

I had similar issue in the past, when I supplied STM32 (the old one, not STM32F4) board via USB and had a bad jumper, so too much voltage drop over J17. So it's always a good idea to search for any voltage drop that may appear over cables, connectors ... Now feeding SEQ(Core&WilbaCS)+LPD+TPD via USB without issues.

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What is the current draw for these parts?  I'm seeing some pull here as well..  The receiver actually gets warm on mine

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Just a quick follow up, I simply snipped the +5V pin on the Dsub connector and powered it from the euro module, works fine..

Edited by Altitude

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I decided to re-spin the boards:

combo.thumb.PNG.b8c5da7fc5145cb67b33167d

 

  • a bit more compact; the idea is to use the panel mount screws for fixing, but there was room for one standoff. If needed, the holes (~3.3mm) in the connector can be utilised instead of soldering down the metal tabs
  • layout improved -- single layer with power/plane on the other side. No vias for the signal lines.
  • +5V is connected through a jumper on both ends, so one could add a power supply if required or disconnect if the cable has too much voltage drop.
  • JAOUT is there, but it would be better IMO to use either a special ribbon cable on the 2*5 or just ensure the AOUT boards have a 1:1 compatible IDC.
  • Alternative connection on a 26-way IDC header. This might be useful if the DB-25 is too chunky or needs a free-hanging connector like this.

s-l1600.jpg

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