Switching from Uno to Mega: warning: left shift count >= width of type

Projects Programming
5

On the Uno

D8 -_> Port B, bit 0
D9 --> Port B, bit 1
D10 --> Port B, bit 2
D11 --> Port B, bit 3
D12 --> Port B, bit 4
D13 --> Port B, bit 5

So there is a nice correspondence between pin # and port B bit #, the -8

If you look at the mega, it is different

D8 -_> Port H, bit 5
D9 --> Port H, bit 6
D10 --> Port B, bit 4
D11 --> Port B, bit 5
D12 --> Port B, bit 6
D13 --> Port B, bit 7

And in your code, you are using pins 12, 10, 11 so

12 - 8 = bit 4 of port B (Not correct, should be 6)
10 - 8 = bit 2 of port B (should be bit 4)
11 - 8 = bit 3 of port B (should be bit 5)

They are all off by 2 so you could edit your code to use a "magic offset" of -6 vs. -8

      PORTB &=~(3UL<<(data_R1-6));                                 // data_R2 is LOW; data_R1 is LOW;
      PORTB &=~(1UL<<(clockPin-6));                                // digitalWrite(clockPin,LOW);
      PORTB |= !((buffer[index]>>(7-i)) & 0x01) << (data_R1-6);  // top set of rows
      PORTB |= !((buffer[index+128]>>(7-i)) & 0x01) << (data_R2-6); // bottom set of rows
      PORTB |= 1<<(clockPin-6);

But now you have Mega specific code.

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