MAX7219 4x8x8 module circuit issue


I have max7219 1088AS module 4 in 1. I figured out my columns are anode and rows are cathode but unable to get information about which segment pins and digit pins are connected to rows and columns. There are four type of modules available like fc-xx, generic, parola and ic -station. i don’t know which is mine. i tried external libraries but not satisfied. i little understand about MAX7219 but required a lot of knowledge.

one thing i didn’t understand that what is a SCANLIMIT . Could anyone make simple code to lit any led with my 4x8x8 module configuration, just i want to understand the working of it.

thanks in advance

So show us a picture of it! Tell us the Web page which describes it?

These are FC-16:

These are “ICStation”:

I think they are essentially identical to FC-16 but am not sure. Marco will know (I am sure!). :grinning:

These are the “old” ones which are not really suitable for stacking:

I do not advise using them except where you just want to use the board to mount the IC and connect to your own LEDs whether in a matrix or some other arrangement. Even then, they are now more expensive than the assemble-it-yourself FC-16 board, so basically obsolete.

If you have the four-in-one module you have the FC-16. You need to add the MD_MAX72xx and Parola libraries using the Library Manager in the IDE. It then contains examples which will make your display work with little effort. You need to alter the code to specify the FC-16 devices and set the number of displays at 4. You don’t need to concern yourself with columns and rows using these libraries.

The “Parola” display is one Marco himself - the creator of the libraries - made but I have no idea how you would obtain them. :roll_eyes: We pretty much all just use the FC-16 modules from eBay.

Scan Limit determines how many cathode columns are activated. For an 8 by 8 display it will always be all so the value is 0xFF (or 0x0F or 0x07 - does not matter).

4 connected modules are almost always FC-16. You need to specify this at the top of each sketch, as per the examples in the library. You also need to make sure that the DATA IN side (where the wires are connected) is on the right of the display.

Scan limit is set to all column by default, so no need to change this for a normal display.

Parola style modules are available from ElectroDragon (no connection to me and I get no $$). Design and PCB files in Eagle format are public domain and can be found on the github site.