PmWiki | Robots / Letters on the Cricket Display

Being slightly bored, I decide that it would be useful if I could somehow display letters on the cricket display. Using a bit of internet research I stumbled upon a site that described the codes needed to give the user arbitrary control of the digits on the display. Using this information I created a function to take four inputs, one for each digit, and make the display change. The inputs would be in the form of an 8-bit number, where bits 0-6 control the state of their corresponding part in the display.

      bit 0
    ----------
   |          |
   |          |
5  |          |  1
   |    6     |
    ----------
   |          |
   |          |
4  |          |  2
   |    3     |
    ----------

For example, the number 0x76 (01110110) is:

7  6  5  4  3  2  1  0
0  1  1  1  0  1  1  0

Resulting in the letter 'H':

| | | | 5 | | 1 | 6 | ---------- | | | | 4 | | 2 | |

Numerous other letters and symbols can be created using different patterns.

Code for the function is below:

void cr8_interface(uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4)
{
	uint8_t waittime = 2;
	uint8_t option = 64;

	// Turn off timer
	TIMSK1 = 0x00;

	TIMSK1 = 0x02;
	cr8_delay(waittime); // Significant Wait required between bytes
	TIMSK1 = 0x00;

	// Send value

	crkbus_send_byte(16,1); // Command Byte

	TIMSK1 = 0x02;
	cr8_delay(waittime);
	TIMSK1 = 0x00;

	crkbus_send_byte(option,0); // Option Byte

	TIMSK1 = 0x02;
	cr8_delay(waittime);
	TIMSK1 = 0x00;

	crkbus_send_byte(b1,0); // 1st panel

	TIMSK1 = 0x02;
	cr8_delay(waittime);
	TIMSK1 = 0x00;

	crkbus_send_byte(b2,0); // 2nd panel

	TIMSK1 = 0x02;
	cr8_delay(waittime);
	TIMSK1 = 0x00;

	crkbus_send_byte(b3,0); // 3rd panel

	TIMSK1 = 0x02;
	cr8_delay(waittime);
	TIMSK1 = 0x00;

	crkbus_send_byte(b4,0); // 4th panel

	// Turn on timer
	TIMSK1 = 0x02;
	cr8_delay(waittime);
}