Max7219 ewg+t and 1088as not working

Projects General Guidance
1

Hello,
I have a problem.
I am using an Max7219 ewg+t with an 1088as. I want to build a Clock with these and somehow I got the wrong 1088as I think.

1088as: Matrix LED 8x8 3mm Rot Matrix 16 Pins 64 LED Anzeige 1088AS REF605 | eBay

Max7219 ewg+t: MAX7219EWG+T Maxim Integrated | Mouser Österreich

I noticed that the Max Chip is a common cathode driver chip and the 1088as is common anode.
But the Matrix still lits up at every led. If i try to send a smily face for example, nothing happens. Not even the clear command. I'm using the MaxMatrix Library.
The schematic:

SchematicOfClock
SchematicOfClock2749×1321 256 KB

They are stacked side by side 16 times!

I hope someone can help me!

Code of smily face:

#include <MaxMatrix.h>

#define data 8
#define load 9
#define clk 10
#define maxInUse 1

MaxMatrix m(data, load, clk, maxInUse);

void setup() {
  m.init();
  m.setIntensity(3);
}

void loop() {
  happy();
  delay(5000);
  normal();
  delay(5000);
  sad();
  delay(5000);
  normal();
  delay(5000);
}

void outline() {
  m.setDot(2,0,1);
  m.setDot(3,0,1);
  m.setDot(4,0,1);
  m.setDot(5,0,1);
  m.setDot(1,1,1);
  m.setDot(6,1,1);
  m.setDot(0,2,1);
  m.setDot(0,3,1);
  m.setDot(0,4,1);
  m.setDot(0,5,1);
  m.setDot(7,2,1);
  m.setDot(7,3,1);
  m.setDot(7,4,1);
  m.setDot(7,5,1);
  m.setDot(1,6,1);
  m.setDot(6,6,1);
  m.setDot(2,7,1);
  m.setDot(3,7,1);
  m.setDot(4,7,1);
  m.setDot(5,7,1);
  m.setDot(2,2,1);
  m.setDot(5,2,1);
}

void happy() {
  m.clear();
  outline();
  m.setDot(2,4,1);
  m.setDot(5,4,1);
  m.setDot(3,5,1);
  m.setDot(4,5,1);
}

void normal() {
  m.clear();
  outline();
  m.setDot(2,4,1);
  m.setDot(5,4,1);
  m.setDot(3,4,1);
  m.setDot(4,4,1);
}

void sad() {
  m.clear();
  outline();
  m.setDot(2,5,1);
  m.setDot(5,5,1);
  m.setDot(3,4,1);
  m.setDot(4,4,1);
}

I know a bit messy but, it was programmd on the fly.

2

That is in fact, a meaningless statement. :roll_eyes:

The MAX7219 is simply an 8 by 8 matrix driver. It will drive any 8 by 8 (monochrome) LED matrix if wired correctly. Matrices are simultaneously "common anode" and "common cathode". The 1088AS and 1088BS are complementary. Your schematic is correct for a 1088BS.

To use the 1088AS you would have to exchange cathode and anode connections. For this reason, I do not purchase modules with the matrices soldered in place! :astonished:

What modules are you using and where did you purchase them?

3

Thanks for the quick awnser!
I have purchased the 1088as at: Matrix LED 8x8 3mm Rot Matrix 16 Pins 64 LED Anzeige 1088AS REF605 | eBay
And the Driver Chips at: MAX7219EWG+T Maxim Integrated | Mouser Österreich
I didn't buy any plug and play Matrix. I designed my own pcb for a Clock that schould display:
(hr/hr/min/min/sec/sec)
(dd/mm/yyyy)
(the day of the week in short(Mon,Thu,Wed,....))
I gues i have to change the connections in the Schematic and then order a new pcb.
Thanks a lot

4

Well, if you have the wrong combination of display and connections, that would be the only way to go.

I see no point at all in re-inventing the wheel. I just use these:

With an ESP-01 to drive them. :grin:

5

I know that these things exist but its really hard to intigrate it into a pcb.
Just look:

Pcb-TopBottom
Pcb-TopBottom1920×2054 393 KB

My uncle heard that I am a hobby electrical engineer and asked if i can make a clock for him. And it would be good if it was in this layout and so on. But I'm gonna make some adjustments.

6

My point is that there is absolutely no need to make your own PCB if the parts to construct it are already available ready-made and relatively inexpensive. It just makes no sense.

The layout you show is easily constructed from the modules I have cited.

What are the components such as "U4", "U5" on your PCB? I gather they are the capacitors.

7

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