max7219 4x 8x8 panels spi

[Ioannis]

Well, I was just about to post that logic analyzer keeps data at zero. I was watching that and could not think what was wrong...!

Doh!

Thanks Richard. Works now.

Ioannis

[Ioannis]

What is the logic in the packing of the characters into words?

Ioannis

[richard]

What is the logic in the packing of the characters into words?

uses half the amount of flash memory when using 7bit numbers [pic16 flash is 14 bits wide] so you need to pack it.
it takes very little time for the pic to unpack so there is no real penalty for a huge saving

[Ioannis]

Yes, OK. But from 6 bytes you went to 3 words. Cannot understand the calculation you did.

;@ db 0x0E,0x10,0x1C,0x10,0x10,0x0E; // Code for char num 51 "3"
@ dw 0x80e,0xe10,0x710

0E=00001110, 10=00010000 and all these makes 80E?

Ioannis

[richard]

0xE=0b00001110, 0x10=0b00010000


and all these makes 80E

7 high bits | 7 low bits
0x10<<7 | 0x0e &0x7f = 0x80e
0b000100000000000 | 0b0001110 = 0b00010000001110 <==> 0x80e [14 bits]

[Ioannis]

After making the paper and pencil homework, I was amazed by your thinking! So simple, so clever, so efficient!

Ioannis

[Ioannis]

Mikroe outputs the characters in columns but your data is in rows. Did you rotate them by hand or can GLCD do that?

Ioannis