Interfacing the MAX7219 LED Driver
felix
Posts: 9
Hello everyone!.
I want to learn how to control a Dot Matrix Display 5*7 and 8*8, with the max7219 driver and the BS2.
I'm trying the circuit and program of the Nuts and Volts, Column #10: Put Your Data Up in Lights Using an LED Display Chip.
I made the right connections in the circuit, but I’m using a Column Anode Dot Matrix Display 5*7 (TA20-11EWA), and the example uses a common-cathode model.
This incompatibility, produce a constant light of all the leds of the display. But I can also appreciate a higher light for the leds animated by the program…
Could anyone tell me what should I change in the code, so that the program works with a Column Anode Dot Matrix Display?. I can’t find the definitions of that parameter…
I attach the basic stamp program in the file DOT MATRIX1.bs2, and the Nuts and Volts, Column #10, so you can see the entire project.
If some one also had more simple examples of who to control a Dot Matrix Display 5*7 (or 8*8) with the max7219 and the BS2, I will really appreciate!.
Thank you!
Felix
I want to learn how to control a Dot Matrix Display 5*7 and 8*8, with the max7219 driver and the BS2.
I'm trying the circuit and program of the Nuts and Volts, Column #10: Put Your Data Up in Lights Using an LED Display Chip.
I made the right connections in the circuit, but I’m using a Column Anode Dot Matrix Display 5*7 (TA20-11EWA), and the example uses a common-cathode model.
This incompatibility, produce a constant light of all the leds of the display. But I can also appreciate a higher light for the leds animated by the program…
Could anyone tell me what should I change in the code, so that the program works with a Column Anode Dot Matrix Display?. I can’t find the definitions of that parameter…
I attach the basic stamp program in the file DOT MATRIX1.bs2, and the Nuts and Volts, Column #10, so you can see the entire project.
If some one also had more simple examples of who to control a Dot Matrix Display 5*7 (or 8*8) with the max7219 and the BS2, I will really appreciate!.
Thank you!
Felix
Comments
· If you're running 7-segment displays, then they have to be common-K.· You could go to a lot of fuss and bother and add a lot of circuitry to use common-A, but that would be silly.
· Now, if you have a program written for a 5x7 using row-anode, column-cathode and you're trying to use row-cathode, column-anode, then you're outta luck again.· You could use it, partially and after a fashion, by swapping the "columns" and "rows" and the result being a '5x5'(if you can deal with that.)
· The deal with the MAX7219s is that the LED anodes (+) go to pins 14, 15, 16, 17, 20, 21, 22, 23 and the cathodes (-) go to 2, 3, 5, 6, 7, 8, 10, 11.· That's just the way it is, you can't invert the programming logic to turn it around, or anything like that.
· As nobody has responed to this Subject/Post,·I figured I'd have a bash.· I say -- go get the right parts.