latigid on
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Posts posted by latigid on
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Backwards 165 IC or resistor network maybe?
Bad cables?
Transistors/diodes interchanged or wrong type of transistors?
Pic of the PCB?
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7 hours ago, niles said:
The bottom 4 (SW17, 18, 19,20) do not register at all. Any idea what this could be?
Probably SW19 is not soldered? Check for continuity across "bridge" marked with silkscreen and solder the pins or temporarily bridge if needed.
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At a guess, some of the components from the seq-plate are shorting out those on le mec. The usual offender is the encoder right above the J89A header, but it could be more around IC3 on le mec, e.g. long diode legs from above.
Check the diode orientation too.
The note numbers from your output can be used to trace events in the NGC:
D#2 = note 39
D#4 = note 63
D#6 = note 87They correspond to the fourth column of buttons, pin 14 of IC2. Check the sixth pin (counted from the left when looking at the top of the seq-plate) of the 10-pin header J2.
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Nearly there! The blood sweat and tears will make it all the sweeter!
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The mini USB shouldn't have much to do with the +5V power, and it could be a dodgy pin contact (the PWR 5V pin as Peter noted) that reconnects when you put pressure on the board.
A little note on connectivity tests: if you probe for connections between +5V/0V lines, you may get a short "beep" as there are capacitors that charge up temporarily. A short circuit on the +5V lines to 0V (which is quite nasty for your USB power supply and probably other components) is only diagnosed as such when you get a continuous beep or 0 ohm resistance.
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Could you check the value/number written on R33D? It does look a bit like an initialisation error. Often this is to do with R33D, hence it is a lower resistance to make the pull-up "stiffer".
Reflowing the resistor shouldn't affect the connection between PA8 and the OLED. Hence it could be something like a cold solder joint or unintentional connection to 0V on R33D, or an intermittent contact on the female header.
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I confess that I'm not 100% sure about how the driver works here. It could be that the data edges are positive-going, meaning the MCU pin drives low for most of the time. This you could probe with your scope.
As the displays work when plugged into the other J15, this would seemingly rule out problems with the OLED itself or cables. Meaning that it's further upstream.
I would trace the E lines back to PC8 and PC9 on the v407 breakout (the header pins are labeled), and also back to the MCU pins. It could be that you have a weird contact on the female header for example.
https://www.waveshare.com/core407v.htm
https://www.waveshare.com/wiki/Core407V
https://www.waveshare.com/w/upload/5/58/CorexxxV-Schematic.pdf
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Next two things to try: check that all required lines are correctly pulled up to 3v3. These are RW (R33A), E2/E1 (R33B/C) and RS (R33D, 560R). All of these pins should be at 3v3 when powered up. Always take care not to short pins together on the OLED when probing!
If you don't have another cable/headers around, you could try to use the SD card one (J16E; the application should start without an SD card). You'll probably have to bend the metal parts holding the display in to remove a cable.
It could also be worth tracing the signals back to the MCU pins.
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Mirroring is very confusing. As you have identified the +5V (unused backlight) and +3v3 (OLED power supply, J15_S is correctly jumpered), you can orient yourself this way.
I don't think I was clear before: with everything plugged in (power off), check for continuity between the two OLED headers, i.e., left OLED pin #1 with right OLED pin #1 and so on. Also check the adjacent pins within one header for shorts, especially on the enable lines.
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The LEDs are quite cheap in bulk, the real cost here is the PCBA. But it is required for such LEDs as there are no pads to solder (they're underneath the LED dies). Plus, reflow soldering of these parts is notoriously difficult and it is very important to control the humidity to avoid lots of dead pixels.
There are other projects around e.g. from @Antichambre and midiphy (myself) that are based on a similar concept.
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5 hours ago, latigid on said:
Check the IDC cable strands don't contact the rear of the OLED PCB. Swap cables to rule out bad cables.
If you haven't done so already, place a bit of tape or even plastic or cardboard between the IDCs and the OLED PCB.
2 hours ago, SimonSays said:if I moved encoders 1-8, it shows steps 1-8... if I move encoder 9+, it shows steps 9-16
Strange! It might be something to do with the E(nable) lines of the cable, so one display is updating with both displays' data.
The schematic is here:
http://ucapps.de/mbhp/mbhp_core_stm32f4.pdf
Note that the pins are "mirrored". If you check J15A/B, you'll see that all pins are common between the two, apart from the E lines. With the power off but everything (except the USB cable) plugged in, use a multimeter in diode/resistance/continuity mode to check that all signals are common between the corresponding pins of the OLED header, also that no adjacent pins are shorted within pin columns of a header. Especially check the enable lines are not shorted to adjacent pins or to each other!
Pins are arranged (view from the top of the display)
02 04 06 08 10 12 14 16 01 03 05 07 09 11 13 15so you need to test e.g. pin 09 for shorts between 08 and 10 etc.
From your previous posts, I think the LCD type is correctly configured (plus I believe the SEQ overrides the bootloader setting), but it could be worth uploading the bootloader app again:
http://ucapps.de/mios32/mios32_bootloader_v1_018.zip
MIOS terminal commands are:
set lcd_type 0x02 storethen restart MIOS Studio and upload the SEQ app again.
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Check R33D (560R not 1k), check the IDC cable strands don't contact the rear of the OLED PCB. Swap cables to rule out bad cables.
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Exciting! Best of luck with the rest of the assembly.
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Hello and welcome! Glad that you're interested in the SEQ v4+.
The functionality is fairly much as before, just the interface is a bit flatter. The obvious difference is the JA subassembly selects what the second row of Matias keyswitches does. But even here there is some familiarity, for instance the tracks are still in "groups" of four with the currently active track coloured differently. Labelled buttons are also almost the same.
For sure, take any SD card. The one on the BOM is just there for posterity -- we don't expect anyone to order it from Mouser. Even if you have some old ones lying around or in an old camera they should be more than enough. Let us know what cards work and or if you have any trouble.
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I can't remember if any of the encoders are mapped to anything. SEQ app or still with _NG?
You can also check if any of the components on the SEQ-plate/lemec short out unintentionally. Normally the issue is with the encoders above the J89/J89A headers. The through-board connectors might also be worth a look.
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Should be 17:
SEQ les mecs, JA = 6
SEQ Core J4A, J19, J11E J19 = 4. J4B is also not required for a SEQ.
Line drivers = 4 (can skip the Receiver if you'd like to build a Euroceiver later)
I2C = 1
MIDI8 = 2 (could skip J2)Where are your 18 from? Core kit BOM says 11, UI kit says 6.
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@SimonSays I think as long as you have 4x virtual USB MIDI ports, the naming is not so crucial. It could be worth flashing the bootloader again. But it seems that _NG is successfully loaded and that SD reads work. Sometimes an SD format can also help.
Possible causes of random DIN events:
- IDC cables incorrectly assembled (wires shorted together or missing, connectors around the wrong way)
- resistor network isolated type; bussed type is correct (ruled out)
- resistor network incorrectly oriented
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shorts between IC pins
- check pins 6/7 as there seems to be some flux/fluff/solder splash etc., also elsewhere on the board.
- Floating IC pins: check 165 inputs (pins 3-6, 10-1) are at +5V.
- IC damage from static or overheating.
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Hello,
First thing to check is if you have soldered the correct resistor network on the JA board?
Second, I think you don't have MB_NG flashed onto the Core? Maybe the SEQ app is flashed?
4 hours ago, SimonSays said:Problem #1 (hopefully, "of 1"!)
Just completed JA board and moving on to testing. On boot/reboot, I'm getting buttons 1, 2, 3 and 5 of the lower row lit on JA, and green light on SD board and red power on Wavemaker (see pic).
If I insert the SD card (FAT32 formatted with ther seq_l file in root only), I get solid amber light and flashing blue on SD board and all lights go out on JA board. This sometimes happens afer reboot without inserting SD card, but always if I do.
Logging from MIOS Studio looks like:
[blue block was reboot with card inserted, block above was without card inserted]
Feels like card *and* button (short?) issues? I can't find the button mapping refs through search...
I've reflowed the SD card connection - the last two are very tight but I don't see a short. Can't see a short on JA board either, but I'm squinting a bit after a day soldering :)
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Hello,
For testing les mecs, you'll want the seq_r.ngc.
The easiest place to test for power is on the J14 three-pin connector on the east side of the board. 0V in the middle, +5V above (marked with the silkscreen). Always test that these pins aren't shorted together before applying power. The other pins I've already mentioned I think. The voltages will depend on the speed of your multimeter and would be best viewed with a scope.
For 595 chips: pins 16 and 10 = +5V; pin 13 = 0V (resistance may be 10k).
For 165 chips: pins 3-6, 10-14, 16 = +5V; pin 15 = 0V.For J89 header, pins 1,2 = 0V, pins 3,4 = +5V,
5 hours ago, niles said:@latigid on Hi I'm at the point of testing the lemec boards, and if you recall I have some issues with the JA board. As you suggested earlier if the power is ok, at least some of the board should work. I just want to make sure power is ok passing through the board, could you let me know what the voltages should be on the pins for SRIO out? Or point me to a link with it, I can't seem to find it via search. Thank you!
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Sure thing, it just depends on how many shift registers you have/want, and how the matrix is arranged.
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Awesome!
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Maybe I'm overthinking it. I think it would be easiest to specify two separate matrices (16x8, 8x8). If the matrix is 8 rows tall, then I think it should still work to specify the same shift register for the selection pulses.
??
DOUT_MATRIX n=1 rows=8 inverted=0 sr_dout_sel1=1 sr_dout_r1=2 sr_dout_r2=3 led_emu_id_offset=1001 DOUT_MATRIX n=2 rows=8 inverted=0 sr_dout_sel1=1 sr_dout_r1=4 led_emu_id_offset=1129
Troubleshooting midiphy SEQ v4+
in MIDIbox SEQ
Posted
Are the note events always the same, no matter what switch is pressed? I can't see any of the parts designators, so I can't help there. It's a bit fuzzy, but the solder joints look rough rather than smooth. So maybe some cold joints are there. Maybe try a slightly higher iron temperature?
The JA board not being connected doesn't affect things.
Are you sure you have seq_r.ngc loaded?
As you have a working le mec, you can compare voltages on IC2 and IC3. Note any differences.