Go Down

Topic: Random on/off with MAX7221 (Read 957 times) previous topic - next topic

wrongway-feldmen

Jan 12, 2016, 03:00 am Last Edit: Jan 12, 2016, 06:03 pm by wrongway-feldmen
I seem to be having trouble finding any real good starting points to get my code for a base running a MAX7221 chip/chips most of what I find is not for random on/off but for things like 8x8 matrix or things like that witch is fine I can modifies that to fit my needs but they aren't for random on/off that I can find all I would like is some help with a basic code to get me started on random on/off of my 64 single LED trough hole lights they will be single colors and RGB mix for light effects

Grumpy_Mike

Post the code you have tried to get to work on a random on off way, and also post the schematic of how you have wired it up.
please read the "how to use this forum" sticky post to find out how to do these things correctly.

wrongway-feldmen

#2
Jan 12, 2016, 06:18 am Last Edit: Jan 12, 2016, 06:29 am by wrongway-feldmen
That the thing I dont know where to start I found out how I can wire the LEDs but no code yet that I can understand and work with as I am just starting out with all of this sorry to be so simple here what I was looking at https://github.com/marcmerlin/LED-Matrix/ and the wiring is on the arduino web site

Grumpy_Mike

Quote
and the wiring is on the arduino web site
Where? This is a big site, link please.

wrongway-feldmen

http://playground.arduino.cc/Main/MAX72XXHardware#Wiring
this is where I am starting from not sure if this is what you mean for a link hope this help and thank you for any help

Grumpy_Mike

Quote
this is where I am starting from not sure if this is what you mean
Well that page offers a number of possibilities and options. We need to know exactly what you are doing. You are the only one who knows, or if you don't then nobody does.

wrongway-feldmen

I want to build a number of 8x8 single through hole led matrix that I can hook up to a MAX7221 chip or 2 then have all the LEDs blink on/off at random and some patterns of my choosing I have seen some on you tube but not sure how it's done

Grumpy_Mike


CrossRoads

The MAX7219/7221 control the outputs by the data you write into their 8 control registers, 1 register for each group of 8 LEDs.
If you want random twinkling, you have to write code that sends the on/off data for the registers.

You can us Display Test to have all turn on/off together at full brightness I think.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

wrongway-feldmen

Thank you so much for your help guys and that link was one I had seen but lost thank you grumpy mike now for the full question sorry but what I am trying to get going is a 8x8x8 cube output from music would like to use something like a msgeq7 chip to input data to and then output to a max7221 chip this would be a RGB LED cube any code for me to get a base from and circuit maybe

Grumpy_Mike

Talk about moving the goalposts!

Paul__B

Haven't built either of my cubes yet, but for the 43, the MAX7219 is the obvious solution.

For the 83 it's not so obvious - a lot of wires if you use the MAX7219s but they do a great job.  Wiring would be simpler using the shift registers - obviously you have to use TPIC6B595s, nine of them with the "layer" register driving eight PNP transistors.  Less wires in the cube proper, but an extra shift register, 8 extra transistors and 64 more resistors.

Not easy either way!

wrongway-feldmen

Haven't built either of my cubes yet, but for the 43, the MAX7219 is the obvious solution.

For the 83 it's not so obvious - a lot of wires if you use the MAX7219s but they do a great job.  Wiring would be simpler using the shift registers - obviously you have to use TPIC6B595s, nine of them with the "layer" register driving eight PNP transistors.  Less wires in the cube proper, but an extra shift register, 8 extra transistors and 64 more resistors.

Not easy either way!

I was thinking that a 595 would be easier also thank you sir do you have a link of how to wire it and code how to run it ?

Go Up