app/pokusy/pokus.c

   1 #include <lpc21xx.h>
   2 #include <types.h>
   3
   4
   5 void delay() {
   6   unsigned u;
   7
   8   for (u = 0; u < 1000000; u++);
   9 }
  10
  11 /*** PWM ***/
  12
  13 int PWM_PINSEL[] = {
  14   /*nothing*/ 1, /*PWM1*/ 1, 15, 3, 17, /*PWM5*/ 11, /*PWM6*/ 19
  15 };
  16
  17 uint32_t *PWM_MR[] = {
  18   (uint32_t*)&(PWMMR0),
  19   (uint32_t*)&(PWMMR1),
  20   (uint32_t*)&(PWMMR2),
  21   (uint32_t*)&(PWMMR3),
  22   (uint32_t*)&(PWMMR4),
  23   (uint32_t*)&(PWMMR5),
  24   (uint32_t*)&(PWMMR6)
  25 };
  26
  27 void pwm_channel(int n, int double_edge) {
  28   uint32_t bit;
  29
  30   PWMPCR |= (0x100 | (double_edge && n)) << n;
  31   if (n == 5) {
  32     PINSEL1 |= 0x00000400;
  33     PINSEL1 &= 0xfffff7ff;
  34   }
  35   else {
  36     bit = 1 << PWM_PINSEL[n];
  37     PINSEL0 |= bit;
  38     bit = ~(bit >> 1);
  39     PINSEL0 &= bit;
  40   }
  41 }
  42
  43 void pwm_set(int n, uint32_t when) {
  44   *PWM_MR[n] = when;
  45   PWMLER |= 1 << n;
  46 }
  47
  48 void pwm_set_double(int n, uint32_t from, uint32_t to) {
  49   *PWM_MR[n-1] = from;
  50   *PWM_MR[n] = to;
  51   PWMLER |= 0x3 << (n-1);
  52 }
  53
  54 void pwm_init(uint32_t prescale, uint32_t period) {
  55   PWMPR = prescale;
  56   PWMMR0 = period;
  57   PWMLER |= 0x1;
  58   PWMMCR |= 0x00000002;
  59   PWMTCR &= ~0x2;
  60   PWMTCR |= 0x9;
  61 }
  62
  63 /***********/
  64
  65 void motor_drive(float u) {
  66   uint32_t d = (float)PWMMR0*(0.5*(1.0+u));
  67
  68   pwm_set_double(2, 0, d);
  69   pwm_set_double(4, d, 0);
  70 }
  71
  72
  73 int main() {
  74   pwm_channel(2, 1);
  75   pwm_channel(4, 1);
  76   pwm_init(0, 50);
  77
  78   motor_drive(0);
  79
  80   for (;;);
  81 }