Max-7221cng 64 led / 8 digit display driver

XDeltaFlameX

New Member
Hello everyone,

Before I start, I am a student in Year 12 (Lower Sixth Form) and while my experience with Picaxe Chips (in general) is pretty substantial, my programming skill and understanding of data communication is poor. I am trying to set up a 4-digit seven-segment display using a 28X2 Picaxe Chip and a MAX7221 Driver, with the intention of displaying whatever data I need on this display, be it integers, decimals or characters (I understanding not all characters/symbols can be displayed given the restriction of 7-seg arrangements). I'd just like to be able to have lots of freedom with what I can display. I've set up a simple circuit, up until interfacing the MAX7221 using an SPI interface. From here on my knowledge is very limited. I'm not sure where to start, how to set up initialization routines (the picaxe SPI setup commands) and the other complicated programming!

ANY help would be very much appreciated!
 

hippy

Technical Support
Staff member
Welcome to the PICAXE forum.

If you use the search function at the top right of the page and search for MAX7221 you should find earlier discussions on using the MAX7221, SPI interfacing, example code and projects using that.
 

inglewoodpete

Senior Member
Welcome to the PICAXE forum.

If you use the search function at the top right of the page and search for MAX7221 you should find earlier discussions on using the MAX7221, SPI interfacing, example code and projects using that.
Getting a PICAXE working as a SPI master is surprisingly simple. The trick will be understanding what configuration data must be sent into the MAX7221 to get it to do what you want.

Which PICAXE model do you intend to use? The X2-series of chips have a lightning-fast and very simple hardware SPI capability.
 

stan74

Senior Member
Why not use a graphic lcd with i2c? £4 ebay. Easy once you know the control numbers to send. I can post code to print text and numbers at screen locations and from help in this forum have plot and draw functions. The oled glcds are very bright.
 
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