Project 2 - Flashing all onboard-LED colour combinations

From the previous project we have seen how to blink LED (white colour). This project post will demonstrate how to flash the on board LED colour combinations without much math.

So the LED is connected as follows.

• RED → PF1
• BLUE → PF2
• GREEN → PF3

Therefore to display red we need to output 0x02, here '2' because PF0 is not being used. Similarly to display purple/violet → 0x06, blue → 0x04, aqua blue/ greenish blue → 0x0c, green → 0x08, yellow → 0x09, white → 0x0e and none → 0.

Now lets focus on the sequence: 0, R, RG, G, GB, B, RB, RGB.

For the above mentioned sequence the system states are as follows: Here the states are addressed as D2D1D0 and the next state as O2O1O0

Present State     Next State     Output

      000                  001              000

      001                  101              001

      101                  100              101

      100                  110              100

      110                  010              110

      010                  011              010

      011                  111              011

      111                  000              111

Lets find the combination for output bit O0 in terms of D2D1D0, for the above drawn table lets make the KMap (3-variable). After Drawing the chart we get,

O0=~D2

Similarly repeat the above steps for O1 and O2. We get,

O1=~D2D1+D2~D0

O2=~D2D0+D2~D1

Now to implement this algorithm in program we need a include file or header file which extracts bits, as it is tedious to repeat the masking procedure multiple times. Click here to view the file.

Program: Click here to view the file
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