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DINX1 on MIOS8 no load signal on RC-line?


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Hello all,

have been troubleshooting this for hours, and need your help.


  • running PIC18460 Core V3 with 16x2 lcd display, running mios 1.9h  -works-
  • uploading of apps -works-
  • midibox_sid_v1_7303e with 24LC512 bank stick -works-
  • connected SID module -works-
  • tested SIO (Serial Input Output) with "srio_interconnection_test_v2a" -works-
  • activated CS in setup file "setup_8580.asm"
  • build DINX1 on verobaord
  • checked pulldown of all DIN-Pins with multimeter -works-
  • checked serial clock witch oscilloscope -works-
  • uploaded "midio128_v2_2c"
  • pressing connected buttons for sending midi-notes -doesnt work- X
  • connecting serial clock to serial out on DINX1 module (for faking input) gives note and cc messages -works-
  • tested 74HC165 in another device (not MIDIbox) -works-
  • swapped PIC18460 -doesn't work- X
  • checked RC-line (i.e. load pin of 74HC165 = pin1) with oscilloscope in 250ns resolution: line is always 5V -???? X
  • checked for shorts, every permutation -none found-

I've checked the connections on the DINx1 dozens of times. It seems to be all good.


for a control surface A (4 buttons + 1 encoder, with button, DINX1) with 16x2 lcd, is there anything specific I have to do in the code?

It still could be the veroboard build of the dinx1, but i doubt that. See attached pics.


Any help is very appreciated.





veroboard dinx1 back.jpg

veroboard dinx1 front.jpg

Edited by synthesizerbauen
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Thank you for your time.

Pin15 (CLI) is indeed connected to ground (which dont't fully understand, because in an Arduino implementation, that pin is used for communication).

Pin7 (QH#) is open.

Pin9 (QH) is open, as it is din1X and not connected to other shift registers.

I used 10k pullup resistors to 5V. When I press any of the buttons or use the encoder, the appropiate Inputs are pulled low (to ground).

I've also checked several times, that all is wired according to 'mphp_din1X.pdf'

I noticed, that there is a setting in the firmware for how many shift registers there are (set to 9). I set this to 1, just for good measure, but to no avail. So I set it back to 9 again.

In have the toolchain to compile the whole thing to hex, so if I should change anything, I can.

Thanks again.


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CLI inhibits clocking in of data. If it floats, probably nothing will be read.

SH should be high "most of the time" as this sends a constant data stream, even if the tail is empty. When RC pulses low, the inputs are read and shifted out. The number of SRs shouldn't matter.

Did you try "set debug on" in MIOS? Not sure if that's enabled for PIC uCapps. Maybe there's another app you can test?

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Do you mean another MIOS app?

tested SIO (Serial Input Output) with "srio_interconnection_test_v2a" -works- all Pins get pulled low as should be.

But this one is interesting:

connecting serial clock to serial out on DINX1 module (for faking input) gives note and cc messages -works-

So basically the PIC can read from the shift register, it just so seems, that none of the inputs do anything. Also I don't notice any activity on Pin1 (LD),

even with 250ns resolution, is that OK?

I will try setting "debug on", waht can I expect? Debug screen messages?


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It's an 8Bit PIC-Core. And I've already checked for continuity to the RC-Pin, its good. The DIN-Test with the MIOS-App "srio_interconnection_test_v2a" gives me exactly what is supposed.

I also get that RC-pulse now, according to  my oscilloscope.

One Button had a strange behaviour, so I disconnected it, nothing changed. Strange behaviour was this: when I hit the button the voltage would go low, but then slowly up again, albeit beeing still pressed.

That's the thing: I've done every test there is and all pass. It's a mystery to me.

But now that I can see the pulse I'm sure it m u s t be my dinx1 implementation. At least something!



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OK, ripping everything apart now and put it together tidy.

But I have a suspicion: which side (PIN) of DINX1 should go to to the core: PIN9 (QH) or PIN10 (SER)?

I had it connected to PIN10 (SER) and while ripping apart it dawned upon me, this was the wrong side...

Will be reporting back with pictures...

Thanks for your help! It's always best to have someone helping you out, when you're stuck and can't bring up new motivation.

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