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BLM 16x16+X build guide


latigid on

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HI all,

 

looks like I'm almost there.  From what I have seen in the power-on test, I have 3 rows not working.  I'm guessing this is down to a cold solder joint or a short.  They are (going by transistor Q number):  Q29, Q19 and Q22.  Would a cold solder joint some place be the top of the list of culprits?

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Are the rows completely unlit or only half? If it's the latter then it could be related to the transistors.

Bases (bottom left) of the transistors connect to the resistor networks:
Q29 connects to pin of RN14, Q19 to pin 14 on RN10, Q22 to pin 10 on RN10.
Emitters (bottom right) connect to ground, but other pins shouldn't. Check if there's a short to ground.

Edited by latigid on
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23 hours ago, TK. said:

Hurray, it's (almost) christmas time ! :)

Note that you could already connect the BLM via a common MIDI IN/OUT connection, e.g. to IN2/OUT2

Best Regards, Thorsten.

I wired up IN2/OUT2 from the sequencer to the DIN8 port on the BLM. I'm not totally confident in the wiring. On the midibox seq4 when I go to the MIDI->Misc. menu and change the BLM_scalar setting to IN2, after a few seconds the sequencer displays a "(found)" message. This seems promising. However, it doesn't seem like the BLM has been configured by the sequencer and I can't do anything with it. Thoughts?

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I can see that the BLM OUT -> MBSEQ IN2 connection is working by looking at the midi monitor. It definitely looks like the output path from the sequencer isn't working. I can see the sequencer sending data on OUT2 when it receives something on IN2. I've wired the midi connections from the MBSEQ directly to the DIN8 connection on the BLM. I'm wondering if this is right. I can swap around the wires to the BLM midi input because I'm just using a breadboard. Hmm. Maybe it's a problem on the mini core? 

IMG_20151216_220935.thumb.jpg.20b80ffdda

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I fixed the BLM midi input issue. It turns out that I had only soldered two pins on the 6N138 optocoupler IC on the minicore. I guess that's what happens when you are building stuff at midnight. So embarrassing... The good news is that the BLM looks like it works. Now I just need to figure out how to use it. :)

Edited by jbdiver
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On 12/14/2015 at 1:46 PM, sbm said:

HI all,

 

looks like I'm almost there.  From what I have seen in the power-on test, I have 3 rows not working.  I'm guessing this is down to a cold solder joint or a short.  They are (going by transistor Q number):  Q29, Q19 and Q22.  Would a cold solder joint some place be the top of the list of culprits?

Well, from bad to worse, looks like my board is shorted now.  Not sure how that happened but I measure 2.5 ohms resistance between ground and 5V.  That was a waste. :-/

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Strange! I won't be able to help much in the next few days/weeks as I'm moving, but I advise to check around all power connections: capacitors (including tants), pin 16 of ICs and RN1..5, check headers and the R1 bridge. The best way is with a hot air rework station and leaving some sort of continuity check across 5V/0V. Thus when you find the fault you only go as far as needed to rectify it. You possibly have a bridge under a capacitor or the soldermask is scratched and the short joins to the groundplane there. Seeing as you're the second to have this issue, I need to consider more plane isolation in the next run... Hope that you can get it back to a good state!

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on the  upper side where the Silicon Contact-Mats are placed: left to the RN17 - is this RN18?

I ask because the Printing on the PCB is ereased, and i dont find any PCB-Layout File or Shematic (where are they? maybe i need them too if i have troubles.)

thx.

(note: the smd parts was fun and fast to solder, but the wired 1N4148 where Hell, cutting bending, cutting again, bending)

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6 hours ago, Phatline said:

on the  upper side where the Silicon Contact-Mats are placed: left to the RN17 - is this RN18?

I ask because the Printing on the PCB is ereased, and i dont find any PCB-Layout File or Shematic (where are they? maybe i need them too if i have troubles.)

thx.

(note: the smd parts was fun and fast to solder, but the wired 1N4148 where Hell, cutting bending, cutting again, bending)

 

I told you the 4148s would be the most painful part! But they do actually provide a "bridging" function that you don't get with SMT parts.

You've got it right: RN17 is on the top side, bottom right corner. RN18 is to the left of RN17, top side, just before the button pads start. 

Schematics available here:
http://www.ucapps.de/mbhp/mbhp_blm_scalar.pdf
http://www.ucapps.de/mbhp/mbhp_blm_map.pdf

I don't intend to publish the layout files; seeing as there are very few users I'm happy to help on a case-by-case basis. 

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Some updates from my side:

1) a new firmware blm_scalar_v1_1 can be downloaded from http://www.ucapps.de/mios_download.html

It contains prebuilt hex files for various hardware configurations:
  o project_without_ain.hex            -> without AIN enabled (use this if J5 pins not connected to ground)
  o project_with_4_mapped_ains.hex     -> for Latigid On's BLM PCB layout, only 4 faders used
  o project_with_4_unmapped_ains.hex   -> AIN pins are mapped 1:1
  o project_with_8_mapped_ains.hex     -> for Latigid On's BLM PCB layout if 4 faders + 4 extension AINs are used
  o project_with_8_unmapped_ains.hex   -> AIN pins are mapped 1:1

 

2) if you are using a PIC18F452, it's required to change the PIC device configuration while flashing the bootloader: the brown out reset level has to be changed from 4.5V to 2.7V as shown in this picture:

blm_scalar_pic18f452_config.png

Otherwise PIC could be reset sporadically (depending on the number of enabled LEDs) because the voltage level could fall below 4.5V!

This change is only required for PIC18F452, other pics (such as PIC18F4620 and PIC18F4685 will work w/o this change).

Unfortunately this change can only be done with a PIC programmer. Please contact me for the case that you don't own a PIC programmer. I could send you a replacement PIC18F452
Alternatively use a PIC18F4620 or PIC18F4685 if you own one

Best Regards, Thorsten.

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51 minutes ago, jbdiver said:
If we are using the standard Latigid On's BLM build, should we use the project_with_4_mapped_ains.hex file? I don't know what "4 extension AINs" means with respect to this project.
 
 

The Mini-Core module has 4 additional analog inputs which are unconnected, and should be tied to ground to avoid that random CC values are transmitted if the project_with_8_mapped_ains.hex firmware is used.

Alternatively (instead of grounding the pins) you can use the project_with_4_mapped_ains.hex file - because it won't scan the unusued analog pins.

51 minutes ago, Phatline said:

the 8 red lights in the picture below > there BUTTONS have no function on my device, the rest of my device is ok.

Where to start with the trouble shooting?

Andy has to help here based on the unpublished layout data.

Best Regards, Thorsten.

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12 minutes ago, TK. said:

The Mini-Core module has 4 additional analog inputs which are unconnected, and should be tied to ground to avoid that random CC values are transmitted if the project_with_8_mapped_ains.hex firmware is used.

Alternatively (instead of grounding the pins) you can use the project_with_4_mapped_ains.hex file - because it won't scan the unusued analog pins.

Many thanks for FW updates. I've added them to the OP.

 

@Phatline

  • Check that all diodes and LEDs have the correct orientation
  • Those middle 8 LED pairs have their cathodes sunk on the transistors nearby (Q37 and Q35) so check the soldering there, also the adjacent resistors.
  • Do all sets of four cathodes show continuity? Are any shorted to ground?
  • Bases of the transistors go to RN18 (not labelled on your PCB) pins 12 and 14 respectively
  • RN outputs to IC18 pins 4 and 2 respectively

 

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5 hours ago, latigid on said:

@Phatline

 

  • Check that all diodes and LEDs have the correct orientation OK
  • Those middle 8 LED pairs have their cathodes sunk on the transistors nearby (Q37 and Q35) so check the soldering there, also the adjacent resistors. Transistors OK, 10K to ground OK.
  • Do all sets of four cathodes show continuity? Are any shorted to ground? No Short2Ground. No active LED @ALL, No Midi-Output-Notes in MIOS-Studio on the input monitor, by pressing the one of the 8 Buttons, no Reaction by giving Note-On-Messages via the midiinput of the BLM. Maybe a software side?
  • Bases of the transistors go to RN18 (not labelled on your PCB) pins 12 and 14 respectively-these are on the backside...dont want to desamble the device....for now
  • RN outputs to IC18 pins 4 and 2 respectively-these are on the backside...dont want to desamble the device....for now

there is no action on the BLM-Midi-Output by pressing one of the 8 buttons.

there is no action on the Buttons-LEDs when receiving (the right) note on/offs via BLM-Midi-Input

 

its a bit tricky to desamble the 32Bit BLM ;)

large.IMG_0677.JPG.bc963c6a3322bf0483533large.IMG_0678.JPG.ed12c36e1cf9d252020e6

Edited by Phatline
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