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linx69
Posts: 46
Hello people, I have a question:...
slowly my overhead goes on, yesterday the components of the electrical panel arrived! :w00t: , I purchased the PCB and the components for the electrical panel of the 737 on the SimBay website (https://simbay.de/gb/simbay-homeockpit-home/69-2-simvim-com-panel-pcb.html#/27-bundle-pcb_components), it is a PCB with two resistors, 14 led digits, and 2 microcontroller max 7219. the connections are: 5v.-GND- L - (load) D (dout) - S1-S2 (CLK 1/2). A microcontroller is connected to the left and middle digits, the other to the right digits. How can I connect them to the mega 2560 since the DOUT and LOAD cables are SINGLE and the clk are 2?:confused:

I use p3D v.4.5- FSUIPC 5-
737 PMDG

saluti Giulio.
2020-05-27 15:35
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pizman82
Moderator
From: ETSI, Germany
Posts: 3521
Supporter
I not see the Datasheet on the Link.

Makes no sense to me the CLK is splitted. I would simply mount the Displays and the Max Chips ( and Resistor) and then i would test.....
On first view the 2 CLK can be combined.....

Mabye this is a wrong label..... Technical it makes mor sense if this are DIN ports.... CLK and LOAD can be each combined.... the DIN can be also splitted so there is no chain and both Chips work single..... Thats more logical as splitting the CLK.

Summary:
If this would be my panel i would testing this by wire both (S1 S2) to one line and bring it to the CLK Pin of the Mega.
No garantee..... Not hate me if this is wrong or destroy something..... Whatever i don´t think so. Whorst case is a error but there should not be a demmage overall !
Good Luck !
2020-05-27 16:59
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pizman82
Moderator
From: ETSI, Germany
Posts: 3521
Supporter
ATTENTION

I try to figure out the lines on the PCB by the Picture ( in case i got no Datasheet)
This looks strange..... Shared DIN without using DOUT..... Maybe this is a strange loogic that is not compatible with Mobiflight.
Best way is to mount the elements and do testings..... "Maybe" you must do some solderwork finaly and use a bypass cable ( and cut a PCB line) to make it work..... But lets talk about this AFTER you test it. Lucky it still work already!
Good Luck !
2020-05-27 17:16
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pizman82
Moderator
From: ETSI, Germany
Posts: 3521
Supporter
UPDATE:
I talked to Stephan.
this Board will not work !! Need a little Rework !

Please note.... If you not already mount the Max7219 Chips then wait..... Its more profitabel here to use a socket cause we must break a line..... More easy if you use a socket that not use this pin instead of cut the line later on the PCB
Good Luck !
2020-05-27 18:35
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linx69
Posts: 46
thanks for the information, if you have any solution to solve it well, I look forward to it .. I don't want to risk damaging the materials even if very cheap compared to others that I have seen on the net for no less than 70 euros
2020-05-27 19:32
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pizman82
Moderator
From: ETSI, Germany
Posts: 3521
Supporter
Most users build this themself without PCB..... Whatever.

Do you got the presolder product or the raw pcb ??

If we understand it correctly then you need to set a wire from DOUT of the Upper Chip ( not used at the moment) to DIN of the lower Chip.
The existing line from DIN to DIN on the PCB should not be used.

So target is.... The second chip should have NOT a connection from the DIN Pin to the PCB hole for that pin...... So you "cut" the internal line.
finaly you solder a little cable from DOUT ( Upper chip) to DIN ( lower chip) and all is fine.
Sure you also must combine both CLK to one line.

In case a socket can be "clipped" on that DIN position verry easy..... if you not use a socket you must get sure the Pin of Max chip not touching the PCB ( OR you use a knife and scratch the PCB line ) Important is.... The DIN Pin of Chip 2 should NOT get in contact with the DIN from Chip 1
Good Luck !
2020-05-27 19:45
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linx69
Posts: 46
ok Grazie, pizman82
I have already soldered all the components, but I can also unsolder the cables that are still not connected to anything. I asked the seller the same thing and he also said that if it was not going well, you have to make a small change, I will turn your message to him, I see what he says.
saluti Giulio.
2020-05-28 09:07
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linx69
Posts: 46
But the photo in the site Sim Bay of this PCB is slightly different
2020-05-28 09:18
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linx69
Posts: 46
the pcb has been modified adding a cable and interrupting a line, in this way the two S will be connected to the same pin on mega working as if it were a single max 7219!
2020-05-28 10:28
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linx69
Posts: 46
Good morning,
here is the work done,

the green cable would be what you designed as purple, the part scratched above in the center is the broken line
2020-05-29 08:45
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linx69
Posts: 46
I hope the images and your advice are useful for anyone who buys this pcb on that site
2020-05-29 08:47
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pizman82
Moderator
From: ETSI, Germany
Posts: 3521
Supporter
Nice.

I delete my posting with the painted image.....
After i see your wirework i thought it´s wrong but i did a mistake in my picture..... So your System should be correct !!!

Please finaly..... Can you confirm the Displays work fine now ?
Good Luck !
2020-05-29 11:38
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linx69
Posts: 46
Thanks pizman, the three new Mega from China arrived today after a wait of almost three months, as soon as I can I try and update.
Greetings Giulio
2020-05-29 12:11
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linx69
Posts: 46
I'm trying to program the display but there are problems: first of all the PMDG offsets show 2 programmable parts, the upper part and with another offset the lower part.

I just connected the display (7 segment, chain of 2) and 4 digits on the right side light up, so only one of the two MAX works.

if I do not go wrong as soon as the cables are connected, all the digits should light up, then once the device is loaded they should all go out.

another problem is that the two rics of offsets divide the display into high and low part,
this pcb has the digitscisì division divided:
MAX 1 digitin upper left, digits lower left and digits low in the center.
MAX 2 digits top and bottom right

Then the offset line says SIZE 13
I only see 1-2-4-8
2020-05-29 17:42
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pizman82
Moderator
From: ETSI, Germany
Posts: 3521
Supporter
Now we talk about 2 problems..... We should solve them each single.

1. Does the Displays work ? Your Panel have a Number for each Display printed on the PCB....
So Chip 1 is used for the Left part (U1 to U8) ..... Chip 2 is used for the Right part. (U1 /2 to U6 /2)

to test the Displays.... make a Testing Config ( whatever Offset) and enable all 8 Diggits of Max1 and Press TEST .... Display should show on Upper Left part 123.... On lower left part 45 and on lower Middle Part 678.
Then Test the second Display ( again all 8 Diggits selected and press TEST in Display Tab).... It should show on Upper right 123 and on lower Right 456.
If this is working then your Hardware and reworking solder is all fine.


2. Configs.

Badly the PDMG show the Data splitted in Lines ( Upper and Lower) But your Hardware PCB split the 2 Max Chips in Left and Right. ( Bad work of PCB creator)
So to solve we need here to Split up the Data String into Blocks..... And also the Display Parts needs multiple Configs.

For example you create a Config for the Upper Left part.... Use the 3 Digits you wire for this.
As Offset you use the String Output that is for the Upper line.... BUT you just use the "part" that is show this 3 Diggits.
Here we work with SUBSTRING. The String (13 Byte) incllude 12 Diggits of the Line ( Top / Bottom)
If you sue Substring 0-3 it will only show the first 3 Digits and CUT all behind.

To show for example the diggits 9-12 you create a NEW concfig line and change the Starting Point of the Offset:
6C40 13 STR(13) ELEC_MeterDisplayTop
So 6C40 is the left digit.... 6C41 is the second 6C42 is the third.... 6C43 is the forth diggit and so on.
If you on next Display use Offset 6C48 then it show Data from Digit 9 and follow.


I don´t know without testing on what diggits PMDG set the needed parts.... Cause PMDG build this offset for a LCD Display (instead of a 7 Segment)
Here you need some testings..... Play with Offset Starting adress and Substring function !
Logical Upper Display is 1-3 and 10-12 .... Lower Display is 1-2 ... 5-7 ... 10-12
Good Luck !
2020-05-29 23:32
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