Author Topic: Issues in communicating with the Preenfm2  (Read 126 times)

New Ignis

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Issues in communicating with the Preenfm2
« on: July 16, 2022, 09:29:33 PM »
Hi, I'm new to the preenFM2, I built one this week.
So far when playing the instrument , all looks fine. Now I want to take it one step further and build a controller for it using the Electra One device https://electra.one/.

To make this happen, I want to set up all communications with NRPN's as much as possible.

But I have things going wrong:

- I may have a faulty DIN-midi out. How can I test this to be sure ?


In the mean time I kept testing using USB MIDI , so I set USB MIDI  to In/Out, Receive to CC&NRPN and Send to NRPN. Sure enough when I now tweak 'Alg' or 'Velo' on the Engine screen, I see the NRPN data being transmitted as a series of 4 CC messages : 99,98,6 and 38.


- When I send the same NRPN instruction from the Electra One into the preenfm2, it does so according to a standard rule that transmits 6 CC messages: the same 99,98,6 , 38 and then followed by the two RPN reset instructions 101 with value 127, and 100 with value 127. I can see the preenfm2 respond to the NRPN instructions, but the preenfm2 immediately turns silent after receiving this row with 6 CC's. Rebooting the preenfm2 is the only workaround found so far. What is causing this?

New Ignis

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Re: Issues in communicating with the Preenfm2
« Reply #1 on: July 18, 2022, 09:06:49 PM »
I did some additional checks:

ON THE FAILING MIDI OUT
- the wiring of the DIN MIDI out connector is correct . I triple checked.
- please find hereby a picture where I indicated in resp. yellow, red and white where I could measure the wires on the PCB are connected to. Is this correct?

- Next test: I've set MIDI out to Thru, and applied incoming MIDI messages. Still nothing is coming out of DIN MIDI OUT.

What can I do ?

About the preenFM2 getting blocked.

- To check why the preenfm2 hangs when receiving CC messages 101 (RPN MSB) and CC message 100 (RPN LSB) both at value 127 or hex 7F (just after NRPN messages 99,98, 6 and 38 are received), I created my own lua version of the NRPN messages where those two 101 and 100 CC are not transmitted, and this time the preenfm2 keeps responding. So the root cause of this is found, and it would be great if it could be fixed in some later update: according to MIDI standard the 100 and 101 message should be able (it is even recommended) to succeed the NRPN. Preenfm2 should not get blocked by it.


EDIT: CAN ANYONE TELL ME HOW I ADD AN IMAGE I MADE MYSELF TO A MESSAGE?
« Last Edit: July 18, 2022, 09:09:40 PM by New Ignis »

Toltekradiation

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Re: Issues in communicating with the Preenfm2
« Reply #2 on: July 19, 2022, 01:38:24 PM »
hi, welcome to the forum,
i encountered some troubles on the pfm2 midi out while back, it may be related :
https://ixox.fr/forum/index.php?topic=69462.msg73019;topicseen#msg73019

to attach image to your message, there is "Attachments and other options" below the text pad.

New Ignis

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Re: Issues in communicating with the Preenfm2
« Reply #3 on: July 20, 2022, 11:40:26 PM »
Thanks Toltekradiation,

I just checked, and it looks the same issue is present on the new PCB as well: both SMD resistors connected to MIDI out pins 4 and 5 are 220 ohm, while the Voltage applied to the pull-up resistor is indeed 3.3V DC, not the 5V needed for 220 ohm resistors. So the resistors should have been 47 instead of 220. I will check if I have 62 or 68 ohm resistors lying around and put them in parallel of the 220 , so I get a total resistance of somewhere between 48 and 52 ohm. That should be close enough.

New Ignis

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Re: Issues in communicating with the Preenfm2
« Reply #4 on: July 21, 2022, 04:33:14 PM »
Not so good news. Applying the two resistors did not help. So I decided s a second attempt to remove the parallel resistor on pin 5 but in doing so I damaged the SMD resistor and its track. I'm not an SMD-expert, so here ends the experiment.  I won't be using the DIN MIDI OUT.

Other remark though: the PreenFM2 reaction to MIDI messages becomes unpredictable if the same message arrives via DIN MIDI at the same time as via USB MIDI. Not a total suprise, it leads to sudden changes in sound timbre or dropped notes. So you better avoid this.

lokki

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Re: Issues in communicating with the Preenfm2
« Reply #5 on: July 21, 2022, 04:57:30 PM »
The midi out is simply one leg of the main processor going thru a resistor, so by looking at the schematic you should be able to find out which leg you have to solder to...I am not home, so can't check for you

Xavier

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Re: Issues in communicating with the Preenfm2
« Reply #6 on: July 26, 2022, 05:27:03 PM »

Sorry for the delay, i'm far from home untill end of August?

That's not good  :-\
I totally forgot about this thread Posted  Toltekradiation

For CC 100,101 after NRPN i never heard about that.
In the preenfm they are use to control arpegiator clock and direction :
https://github.com/Ixox/preenfm2/blob/master/src/midi/MidiDecoder.h#L119

It should be easy to build a firmware after removing those 2 CCs from MidiDecode.cpp.

Sorry to read that about the Din5 out.
I've never seen this problem on the hardware i have and i finally have very few reports of incompatible hardware.
I'll need to have a look i made other PCB batchs one day.