# Measurement of MAX7219 8*8 LED Light Signal Transmission Rate

Hi, Everyone

I am doing a project using Arduino Uno board, MAX7219 connects with 8*8 LED light. My goal is to measure how fast the analog signals are transmitting from CPU to the board. Also, I want to know what is the time elapse between lighting up the first light(Light (1,1)) and lighting up the last light(Light (8,8)) by using Oscilloscope. My question is how to measure the time elapse between each light on the matrix lighting up with an oscilloscope? and how to speed it up from both hardware and software perspective?

Hope you could understand the question! Let me know if any part is confusing, and let me know what other information u need for solving the problem!

Sincerely,
JC

My goal is to measure how fast the analog signals are transmitting from CPU to the board

Which analogue signals?

What's wrong with a couple of photodiodes and resistors?

Sorry for confusing, I want to measure how fast the analog signal transmitted between different lights on the MAX7219 8*8 matrix by using an oscilloscope. i.e. the time transmitted between the first light and the last one. I would like to check whether the time elapsed is less than 100ms or not.

I'll repeat myself (only once) - what analogue signal?

JudyChen232:
Sorry for confusing, I want to measure how fast the analog signal transmitted between different lights on the MAX7219 8*8 matrix by using an oscilloscope. i.e. the time transmitted between the first light and the last one. I would like to check whether the time elapsed is less than 100ms or not.

Are you asking for someone to tell you how to use the oscilloscope?

Paul

AWOL:
I'll repeat myself (only once) - what analogue signal?

Hi, I am working on an analog electrical signal! Is this what you are asking about? Sorry for confusion before!

Sincerely,
JC

Paul_KD7HB:
Are you asking for someone to tell you how to use the oscilloscope?

Paul

Hi, Paul

Yes, I want to understand how to read oscilloscope, especially the USB oscilloscope: the technique I use is PISCO 2000, and the software I use is PicoScope6. I have watched so many youtube videos, but they do not teach me how to differentiate between background noise and the real signals I want. The signals I want to read from oscilloscope is the signal that indicates the lightning of the light, once I understand that, I could possibly know the time interval between lightning the first light and the second light.

The picture in the attachment is the shows the lightning of one LED light. I am not sure if the cycle I read is right or not. The two lines indicate the cycle that I read my time.

Sincerely,
JC

Paul_KD7HB:
Are you asking for someone to tell you how to use the oscilloscope?

Paul

Hi, sorry, I forgot to attach the image in my last post

JC

JudyChen232:
Hi, sorry, I forgot to attach the image in my last post

And didn't read the instructions, or understand what a Web browser is.

OK, so it seems you are either wondering about the strobe timing of the MAX7219, not being satisfied with reading the datasheet, or simply wish to test your oscilloscope program for which the MAX7219 sounds an excellent test case. You have however made it an "XY Problem".

Note that the MAX7219 drives (up to) eight LED anodes at a time and switches one of (selectable) eight cathode lines in succession.

While the oscilloscope is designed to read analog voltages, the MAX7219 is a digital device which does provide current regulation to the anode drivers and is in this respect, "analog". I presume if you wish to do this, you have a MAX7219 display module attached to an Arduino and programmed to display some specific (fixed) pattern. You need to confirm this in detail.

Once you have that, you attach the oscilloscope ground clip to the MAX7219 display module ground, and the input to one of the anode driver pins of the MAX7219.

And if we are looking at imgur. I rather like this picture next in the stream.

Hi,

Paul__B:
And didn't read the instructions, or understand what a Web browser is.

OK, so it seems you are either wondering about the strobe timing of the MAX7219, not being satisfied with reading the datasheet, or simply wish to test your oscilloscope program for which the MAX7219 sounds an excellent test case. You have however made it an "XY Problem".

Note that the MAX7219 drives (up to) eight LED anodes at a time and switches one of (selectable) eight cathode lines in succession.

While the oscilloscope is designed to read analog voltages, the MAX7219 is a digital device which does provide current regulation to the anode drivers and is in this respect, "analog". I presume if you wish to do this, you have a MAX7219 display module attached to an Arduino and programmed to display some specific (fixed) pattern. You need to confirm this in detail.

Once you have that, you attach the oscilloscope ground clip to the MAX7219 display module ground, and the input to one of the anode driver pins of the MAX7219.

Hi, Paul

Thanks for your reply! It really helps me with the way I am thinking of my project! Yes, you are right, I am trying to use an oscilloscope to measure the MAX7219 analog transmission! Since when time goes much shorter when the frequency goes a lot higher, the oscilloscope measurement reaches the limitation, so that, right now, I am trying to use another measurement method! i will keep you update if you are interested in this topic!

Sincerely
JC