Bad Max7219?

Hello, I am creating an 8x8 Led Matrix. I seem to be having some issues. When I upload a program to the Arduino the matrix doesnt work. All of the LED's stay off. I removed the IC from the board and tested the continuity between the pins and Seg A,F,E,C,D,DP All are connected. Is this a bad IC Thank you.

Could be many things: - not properly powered - wrong wiring - wrong code (pin assignment etc)

Double check wiring (post photo), double check the code (post code).

I cant post a picture right now but i can soon. As for wrong wring i physically removed the IC from the board So there was no wires when i tested the continuity. Ive used the code found on this website http://www.electroschematics.com/10510/arduino-8-8-led-matrix/ Because it was a easy recognizable shape. To Power the Max I simply used an external 5v power supply and i tied the Ground from the arduino into the max also

and tested the continuity between the pins and Seg A,F,E,C,D,DP

Test the resistance not continuity. If it is zero then it is a bad or fake chip, otherwise you can't tell anything else from the measurement.

Unfortunately those pins measure 1ohm to 5 ohms all other pins are 1500ohm+ is it dead :confused:

is it dead

Maybe.

What I would do next is to connect the clock pin to a PWM pin power it up and ste the PWM pin to a value of 128. Then set the Din pin high and see if the Dout pin goes high, then do the same with Din low. While there will be a delay of 16 clock pulses while the Din gets to the Dout feeding it with PWM will be so fast it will look continuous.

  • What board? Who made it?
  • What matrix? Who made it?
  • Did the LEDs ever light up?

Grumpy_Mike: Maybe.

What I would do next is to connect the clock pin to a PWM pin power it up and ste the PWM pin to a value of 128. Then set the Din pin high and see if the Dout pin goes high, then do the same with Din low. While there will be a delay of 16 clock pulses while the Din gets to the Dout feeding it with PWM will be so fast it will look continuous.

Explain more? I am sorry, I am newish to micro controllers.

I made the The board and the matrix. A 16 pin ribbon cable connects it to the MAX When i connect the ribbon cable backwards most of the the leds light up

liljoey112: I made the The board and the matrix.

OK, so we now know you made a mistake in the wiring.

liljoey112: A 16 pin ribbon cable connects it to the MAX When I connect the ribbon cable backwards most of the the leds light up

So the chip is presumably working. Good.

Before you do anything more we need to see perfectly focused photographs (in daylight) clearly showing all of your wiring with nothing obscured. As links in the text to wherever you have lodged the photographs.

Yes, and the code you are using. Post it here in the message text using the "code" tags. Read the instructions first though.

No "attachments" please, all details linked in the text.

Explain more?

That is the full explanation. If there is anything specific you don't understand then ask about that specifically.

It is a test I devised just for you to enable you to test part of your chip without having to resort to testing it all. If that test don't work then your chip is FUCT (Further Use Completely Terminated )

Okay Pictures and code Coming as soon as possible Hopefully with in the hour as for i undersold the ribbon connector because i thought that was the problem

then your chip is FUCT (Further Use Completely Terminated )

NFG (Not Functioning Good)