PROB5: LED

Pseudo-drive an LED display.

DESCRIPTION

A standard digital LED display is N blocks (digits) of the device in the figure. There are eight wires tied to the microcontroller for each of the eight led segments in the block. You are to write the conversion of decimal numbers to a format suitable for driving such a display.

The convention for an LED driver is to write a logical 1 when the corresponding segment is off, and to write a 0 when the segment is on.

The basic digit formats corresponding to the segment labels in the figure are as follows:

Digit	Segment								Hex
	7	6	5	4	3	2	1	0
0	1	0	0	0	1	0	0	0	0x88
1	1	1	0	1	1	0	1	1	0xDB
2	1	0	1	0	0	0	1	0	0xA2
3	1	0	0	1	0	0	1	0	0x92
4	1	1	0	1	0	0	0	1	0xD1
5	1	0	0	1	0	1	0	0	0x94
6	1	0	0	0	0	1	0	0	0x84
7	1	1	0	1	1	0	1	0	0xDA
8	1	0	0	0	0	0	0	0	0x80
9	1	1	0	1	0	0	0	0	0xD0

The hex column comes from considering each segment value as one bit of a byte, with segment 7 the most significant bit and segment 0 as the least significant bit. This is the byte written to the control port for the LED segment to conform to the corresponding digit. Turning off bit 7 (the most significant bit) enables the display of the decimal point. For example, displaying a "0." on an LED block corresponds to writing binary 0000 1000, or hexademcimal 08, to the segment driver port.

In this problem, you are to generate the byte values to be written to an led display driver to display decimal numbers in various fixed point formats.

INPUT: prob5.dat

The input file will contain a sequence of decimal formatting problems. These will be written as three comma-separated numbers on a line:


WIDTH,PRECISION,VALUE


The WIDTH will be the width of the display, which will be between 1 and 12 digits. The PRECISION will be the number of decimal places after the decimal point which should be displayed. PRECISION will always be non-negative and smaller than WIDTH. The VALUE is the value to be displayed, which will always be non-negative with magnitude less than 10^WIDTH-1. VALUE will have fewer than 64 digits.

An example input file would be:

       column   1111111111222222222233333333334
       1234567890123456789012345678901234567890
line 1:8,0,0.15707963267948966192313216916398[EOL]
     2:8,1,0.15707963267948966192313216916398[EOL]
     3:8,2,0.15707963267948966192313216916398[EOL]
     4:8,3,0.15707963267948966192313216916398[EOL]
     5:8,0,1.5707963267948966192313216916398[EOL]
     6:8,1,1.5707963267948966192313216916398[EOL]
     7:8,2,1.5707963267948966192313216916398[EOL]
     8:8,3,1.5707963267948966192313216916398[EOL]
     9:8,4,1.5707963267948966192313216916398[EOL]
    10:8,5,1.5707963267948966192313216916398[EOL]
    11:8,6,1.5707963267948966192313216916398[EOL]
    12:8,7,1.5707963267948966192313216916398[EOL]
    13:8,1,15.707963267948966192313216916398[EOL]
    14:8,1,157.07963267948966192313216916398[EOL]
    15:8,1,1570.7963267948966192313216916398[EOL]
    16:8,1,15707.963267948966192313216916398[EOL]
    17:8,1,157079.63267948966192313216916398[EOL]
    18:8,1,1570796.3267948966192313216916398[EOL]
    19:8,1,15707963.267948966192313216916398[EOL]
    20:1,0,0[EOL]
    21:1,0,1[EOL]
    22:1,0,2[EOL]
    23:1,0,3[EOL]
    24:1,0,4[EOL]
    25:1,0,5[EOL]
    26:1,0,6[EOL]
    27:1,0,7[EOL]
    28:1,0,8[EOL]
    29:1,0,9[EOL]
      :[EOF]

OUTPUT: prob5.out

Here are the general display rules:

• The padding will always be on the left with blanks (byte 0xFF).
• The decimal value will be rounded to the precision defined. If the magnitude of the number does not allow for the display of all the requested digits of precision, then the value will be rounded to the available digits on the display. A value exactly between two rounding choices should be rounded so that the last digit of the rounded value is even. For example, 0.0015 would round to 0.002 with three digits of precision, while 0.0045 would round to 0.004.
• Values with magnitude less than 1 will be displayed with a leading "0." (byte 0x08)
• The decimal point is always displayed.

Other than the standard leader an trailer, the output file simply has the bytes to be written to the display driver in hexadecimal format.

The correct output corresponding to the example input file would be

       column   111111111122222222223
       123456789012345678901234567890
line 1:Program 5 by team 0[EOL]
     2:FF FF FF FF FF FF FF 08[EOL]
     3:FF FF FF FF FF FF 08 A2[EOL]
     4:FF FF FF FF FF 08 DB 84[EOL]
     5:FF FF FF FF 08 DB 94 DA[EOL]
     6:FF FF FF FF FF FF FF 22[EOL]
     7:FF FF FF FF FF FF 5B 84[EOL]
     8:FF FF FF FF FF 5B 94 DA[EOL]
     9:FF FF FF FF 5B 94 DA DB[EOL]
    10:FF FF FF 5B 94 DA 88 80[EOL]
    11:FF FF 5B 94 DA 88 80 88[EOL]
    12:FF 5B 94 DA 88 DA D0 84[EOL]
    13:5B 94 DA 88 DA D0 84 92[EOL]
    14:FF FF FF FF FF DB 14 DA[EOL]
    15:FF FF FF FF DB 94 5A DB[EOL]
    16:FF FF FF DB 94 DA 08 80[EOL]
    17:FF FF DB 94 DA 88 00 88[EOL]
    18:FF DB 94 DA 88 DA 50 84[EOL]
    19:DB 94 DA 88 DA D0 04 92[EOL]
    20:DB 94 DA 88 DA D0 84 12[EOL]
    21:08[EOL]
    22:5B[EOL]
    23:22[EOL]
    24:12[EOL]
    25:51[EOL]
    26:14[EOL]
    27:04[EOL]
    28:5A[EOL]
    29:00[EOL]
    30:50[EOL]
    31:End of program 5 by team 0[EOL]
      :[EOF]