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nid help on LED blinking

james yeo

i have problem with the led blinking. I using the exmaple program given by keil using uVision3. When i run the program, the LED on the development board didnt blink, it just stay on! wat should i do?

thanks!

Parents
  • 0 in reply to ImPer Westermark 

    
  unsigned char j;                    /* LED var */

.
.
.

    for (j=0x01; j< 0x80; j<<=1)
    {
      .
      .
      .
    }

    Because j is an unsigned char, the test for j<0x80 will always be true and you will never exit the loop.

    Pass#1 j = 0x01
    Pass#2 j = 0x02
    Pass#3 j = 0x04
    Pass#4 j = 0x08
    Pass#5 j = 0x10
    Pass#6 j = 0x20
    Pass#7 j = 0x40
    Pass#8 j = 0x80
    Pass#9 j = 0x00
    ...
    Pass#n j = 0x00

Reply
  • 0 in reply to ImPer Westermark 

    
  unsigned char j;                    /* LED var */

.
.
.

    for (j=0x01; j< 0x80; j<<=1)
    {
      .
      .
      .
    }

    Because j is an unsigned char, the test for j<0x80 will always be true and you will never exit the loop.

    Pass#1 j = 0x01
    Pass#2 j = 0x02
    Pass#3 j = 0x04
    Pass#4 j = 0x08
    Pass#5 j = 0x10
    Pass#6 j = 0x20
    Pass#7 j = 0x40
    Pass#8 j = 0x80
    Pass#9 j = 0x00
    ...
    Pass#n j = 0x00

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