text unreadable on MAX7219

I have got this project working, but the text etc is unreadable on the MAX7219 led mudule.

There is little to no documention to help set the clock up etc, and I hoped it wouldn’t be as difficult as this. All you can see is the author pressing the different buttons to make the changes, and I have tried to do the same here , but it is not very clear with the figures/numbers and the flashing double dots

The author says:
NOTE: MD_MAX72xx library must be installed and configured for the LED
// matrix type being used. Refer documentation included in the MD_MAX72xx
// library or see this link:
// MD_MAX72xx LED Matrix Arduino Library: Hardware

I have asked the author what are the changes I need to make in the MD_MAX72XX/src/MD_MA72XX.h, but have no reply at all from the author.

I am seeing seconds first in smaller digits, then: 105:1:1
Pressing the midlle button I get: seconds first, then 0:1:015, then the rest is unreadable

So , if someone can tell me here it would be great.

MAX7219_RTC_dht11.ino (12.6 KB)

MD_MAX72xx.h (41.2 KB)

You need to verify that you have the FC-16 LED modules. It should say that right on the silkscreening.

It looks like https://majicdesigns.github.io/MD_MAX72XX/_m_d___m_a_x72xx_8h.html does not exist. The link to it is on https://majicdesigns.github.io/MD_MAX72XX/page_software.html

I had an old version of the library and I was able to tell it that I had the FC-16, but with this new one I cannot figure where you are suppose to define which LED module you have so the library works for it!

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Take a look at the example Parola_HelloWorld

It shows you how to set which LED module you have. change MD_MAX72XX::PAROLA_HW to MD_MAX72XX::FC16_HW

lee488, I do have the FC-16 modules, as there are 4 of them with each board soldered together.

Aslo if you mean this part:

enum MD_MAX72XX::moduleType_t

Module Type enumerated type.

This enumerated type is used to defined the type of modules being used in the application. The types of modules are discussed in detail in the Hardware section of this documentation.

Enumerator

PAROLA_HW Use the Parola style hardware modules.

GENERIC_HW Use 'generic' style hardware modules commonly available.

ICSTATION_HW Use ICStation style hardware module.

FC16_HW Use FC-16 style hardware module.

There is no options to change anything , except I did try FC16-HW 1, but the sketch would not compile and I didn't klnow what to do to get it to compile. It was all to do with: enum MD_MAX72XX::moduleType_t

If I did change it to FC-HW 1, and run the sketch to get the error message, could I upload it to here for someone to help me with it.

Thanks

You are NOT suppose to modify the .h file !!!!

ieee488: Take a look at the example Parola_HelloWorld

It shows you how to set which LED module you have. change MD_MAX72XX::PAROLA_HW to MD_MAX72XX::FC16_HW

Where is that line , as I have 2 folders , : MD_MAX72XX, and MD_Parola. Or is it in the sketch.

Thanks

Again, look at the example sketch called Parola_HelloWorld.

Ah yes, I see it now, and in the sketch for the project it is already:

define HARDWARE_TYPE MD_MAX72XX::FC16_HW.

But the text is still not readable in some places.

I have uploade the Hello World sketch, and the word Hello is in reverse with 3 letter l's ollle h. The letter H is part way off the screen.

I have also just tried the Parola_Print_Minimal, which prints Hello, and the word is upside down. BY mistake I left the Hardware type as Parola_HW, and yes the who word is upside down. Now changed the Hardware type to FC16_HW and the word is all mixed up

Have you tried rotating the LED modules? In addition, the LED modules must be "common cathode" for them to work in the FC-16 printed circuit boards.

The LED modules are all soldered onto a board, so I can't rotae the LED modules.

Sorry, common cathode is a bit over my head.

Maybe the MAX7219 is faulty??

It is more likely that the LED modules are the wrong type. Very common with cheap parts purchased on eBay.

Are there markings on them on the side? If so what are they? That will tell us what kind you have.

Also, what pins are you using for your CLK, DATA, CS ? The Parola sketches are written assuming you have them connected to the hardware SPI on your Arduino.

ieee488: In addition, the LED modules must be "common cathode" for them to work in the FC-16 printed circuit boards.

Well, they either work or they don't, there is no half way so that is not the problem!

avalon66: The LED modules are all soldered onto a board, so I can't rotate the LED modules.

Not necessary. Look further in the documentation and you wil find the switches to invert or rotate the display.

avalon66: Sorry, common cathode is a bit over my head.

Turns out that was not meaningful. If it displays, the modules are working.

avalon66: Maybe the MAX7219 is faulty?

Not too likely on a salvaged commercial product.

i can only see markings on the first from connector pins, and it says 1088A, then the bottom of another letter or number, but only quite faint. When I typed 1088A into a search box it came back as 1088AS.

CLK is on Pin 13
DATA is on Pin 11
CS is on Pin 10

These are as per the schematic for the project.

As a test I changed the HARDWARE_TYPE MD_MAX72XX:: FC16_HW to MD_MAX72XX::PAROLA_HW

Now the numbers for the clock are turned through 180 degrees, with the seconds at the right hand side instead of the left side, and that is all it does, everything else is upside down.

MAX7219 Dot Matrix 4-in-1 8x32 dot matrix common cathode.jpg

Paul__B: Well, they either work or they don't, there is no half way so that is not the problem! Not necessary. Look further in the documentation and you wil find the switches to invert or rotate the display. Turns out that was not meaningful. If it displays, the modules are working. Not too likely on a salvaged commercial product.

Yes they are common cathode as I found out.

What documentation are you referring to, because the only information I can find is written at the top of the sketch, which is not helpful.

Ok, I found the said documentation where it says:

The compile options start with USE_ and are documented in the section related to the main header file MD_MAX72xx.h.

NOTE: Compile switches must be edited in the library header file. Arduino header file 'mashing' during compilation makes the setting of these switches from user code completely unreliable.

In the said file there is no options to change anything as such. and when I did try to change FC16_HW to FC16 1, the sketch did not compile. there is a line in the scketch which defines hardware type to FC16_HW.

I was also told not to change anything in the sauid file.

Is there any other documentation which says what you say.

avalon66: Ok, I found the said documentation where it says:

The compile options start with USE_ and are documented in the section related to the main header file MD_MAX72xx.h.

NOTE: Compile switches must be edited in the library header file. Arduino header file 'mashing' during compilation makes the setting of these switches from user code completely unreliable.

In the said file there is no options to change anything as such. and when I did try to change FC16_HW to FC16 1, the sketch did not compile. there is a line in the scketch which defines hardware type to FC16_HW.

I was also told not to change anything in the sauid file.

Is there any other documentation which says what you say.

That is documentation for the older version.

Have you removed everything from your Arduino except the LED display board?

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Paul__B: Not necessary. Look further in the documentation and you wil find the switches to invert or rotate the display.

Where?

I don't see it.

In addition, you are confused. His is not the salvaged commercial product in the other thread.

I took out a former project with 5 of the FC-16 boards connected. 1088AS LED matrices

I upgraded to the latest version of MD_MAX72XX and MD_Parola libraries.

I took the Parola_HelloWorld example sketch and changed HARDWARE_TYPE to MD_MAX72XX::FC16_HW and MAX_DEVICES to 5 to match my hardware

and it works.

. . .

I still haven't figured which file to modify so that the FC-16 will work with the 1088BS LED matrices. I am all ears for someone to enlighten me!

.

I ordered another MAX7219 set of leds/lights, and it came earlier today.

After messing about with different bits etc, I decided to plug the DS1307 straight into the breadboard and connect the wires from that.

Using the new MAX7219 the text/numbers are the right way up, and the seconds are on the right side of the minutes instead of the left side of the hour.
I set both the time and year, and it ran, but the time is not updated, .

What do you see or have on the right side of the hour, as I thought that it was minutes, but the selector takes it up to 95, so maybe that is not minutes??

Hve you had chance to cyle through the different texts which can be changed.

In the oictures you will see what I am seeing just now, and 1 picture shows signs and other objects, do yo get that.

Thanks