788BS 8x8 LED Matrix HELP

Literally NO ONE has tutorials on the 8x8 LED Matrix I have, and I hate it. I'm a beginner at Arduino and I'm so scared I'm going to burn out either my only matrix, or more importantly, my Arduino Uno WiFi Rev2. Any tutorials, datasheets, or any resources for this stupid and [[possibly]] outdated LED matrix? It has the 8 pins on the top and bottom sides, not the bottom and left/right on most other parts.

Well, it is easy enough to find the datasheet.

However I am going to point out that it is a basically futile approach to connect it directly to an Arduino - and I am not at all sure of the driving capabilities of an "Arduino UNO WiFi Rev2" either as I do not have one nor do I ever imagine any need for it! :astonished:

The proper way to drive an 8 by 8 (monochrome) matrix is to use the chip specifically designed for it, the MAX7219. The irony here however is that the cheapest and most practical way to obtain these on eBay is to buy two or three of these kits:

Or these ones

which used to be more expensive but are now actually cheaper and more useful if you wish to stack matrix arrays.

The point is that they already come with the matrix display and are generally cheaper than buying either of the parts separately. :roll_eyes:

Your matrix looks perfectly normal to me.

I believe I understand what you mean about placement of pins. You are confused between the physical placement of pins on the package and the schematic representation of the matrix. Your matrix is normal, they all have 8 pins top and 8 bottom. Schematics always show them with 8 pins top and 8 pins left or whatever. Schematics don't have to reflect the actual layout of pins, they show them in the most logical and easy to understand representation in a circuit diagram.

Getting a max7219 chip would indeed be the easiest and best way to drive your matrix. There are other ways, but they are more complex or don't give as good results, or both. What other components do you have that you think might be useful? Other chips, transistors...?

In the most basic circuit, all you need is 8 resistors. But the resistors need to be a higher value than the 220R or 330R normally used with individual LEDs. Something around 750R~1K would be ok, but the matrix will not be very bright as a result. But enough to see indoors, for a practice circuit.

Before you wire up your circuit, draw a schematic diagram and post it here. Hand drawn is fine if it is neat. We can check it and first and then you don't need to worry about burning your Arduino or matrix.

Bump.

I am also having the same problem. I am having the worst time finding a tutorial, without the I2C controller, for the 788BS 8x8 LED matrix. I am looking for how to wire it with resistors and what not on the bread board, the code I think I have a fair grasp on.


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Note pins run clockwise viewed from underneath. Whether you wire the resistors to anodes or cathodes depends on how you propose to arrange the code. Resistors need to be 1k or more.

koltinb12:
... finding a tutorial ... for the 788BS 8x8 LED matrix. I am looking for how to wire it with resistors and what not on the bread board, the code I think I have a fair grasp on.

Read the previous posts. 788BS is not unusual in any way, is a perfectly standard matrix. All you need for the most basic circuit is 8 resistors (750R~1K) and 16 Arduino pins. You can use the analog pins as digital pins on most Arduino (except A7&A8 on Nano).