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Revision 812788aa

ID812788aa5bc592cf417de345fdd8a74933d7a0c8
Parent 0e77683c
Child cc9ca04e

Added by Thomas Mullins over 11 years ago

Moved some sensors to different timers

Most notably, change the ROS millisecond counter to share the BOM 38 kHz
timer instead of having its own. The range sensor and BOM rx will now
share timer 5, but they both have to be fixed for the higher F_CPU.

View differences:

scout_avr/src/Atmega128rfa1.cpp
1 1 
#include "Atmega128rfa1.h"
2 
#include "bom.h"
2 3 

  		




  3
  4
  
    
extern "C"


  		




  4
  5
  
    
{


  		




  ......




  7
  8
  
    
  void __cxa_pure_virtual(void) {}


  		




  8
  9
  
    
}


  		




  9
  10
  
    

  		




  
  11
  
    
#define T0_KHZ 76


  		




  
  12
  
    
#define T0_OCR (F_CPU / 1000 / T0_KHZ) // 210 ticks


  		




  
  13
  
    
#define T0_ERROR (F_CPU / 1000 - T0_OCR*T0_KHZ) // 40 ticks/ms


  		




  
  14
  
    

  		




  
  15
  
    
unsigned char t0_count, t0_error;


  		




  10
  16
  
    
unsigned long millis;


  		




  11
  17
  
    

  		




  12
  18
  
    
int rx_start = 0, rx_end = 0;


  		




  ......




  18
  24
  
    

  		




  19
  25
  
    
ISR(TIMER0_COMPA_vect)


  		




  20
  26
  
    
{


  		




  21
  
  
    
  millis++;


  		




  
  27
  
    
  bom_isr();


  		




  
  28
  
    

  		




  
  29
  
    
  // F_CPU = T0_OCR * T0_KHZ + T0_ERROR


  		




  
  30
  
    
  // every millisecond, accumulate T0_ERROR, and when it reaches T0_OCR skip


  		




  
  31
  
    
  // one iteration


  		




  
  32
  
    
  t0_count++;


  		




  
  33
  
    
  if (t0_count >= T0_KHZ) {


  		




  
  34
  
    
    t0_error += T0_ERROR;


  		




  
  35
  
    
    if (t0_error < T0_OCR) {


  		




  
  36
  
    
      t0_count = 0;


  		




  
  37
  
    
    } else {


  		




  
  38
  
    
      t0_count = -1;


  		




  
  39
  
    
      t0_error -= T0_OCR;


  		




  
  40
  
    
    }


  		




  
  41
  
    
    millis++;


  		




  
  42
  
    
  }


  		




  22
  43
  
    
}


  		




  23
  44
  
    

  		




  24
  45
  
    
ISR(USART0_RX_vect)


  		




  ......




  54
  75
  
    
  // === init time ===


  		




  55
  76
  
    
  // COM0x = 0, pin OC0x not used


  		




  56
  77
  
    
  // WGM0 = 2, clear timer on compare match, TOP = OCRA


  		




  57
  
  
    
  // CS0 = 3, 64 prescaler


  		




  
  78
  
    
  // CS0 = 1, no prescaler


  		




  58
  79
  
    
  TCCR0A = _BV(WGM01);


  		




  59
  
  
    
  TCCR0B = _BV(CS01) | _BV(CS00);


  		




  
  80
  
    
  TCCR0B = _BV(CS00);


  		




  60
  81
  
    
  // enable interrupt on compare match A


  		




  61
  82
  
    
  TIMSK0 = _BV(OCIE0A);


  		




  62
  
  
    
  // 1 ms with 1/64 prescaler


  		




  63
  
  
    
  OCR0A = F_CPU / 1000 / 64;


  		




  
  83
  
    
  OCR0A = T0_OCR;


  		




  64
  84
  
    
  millis = 0;


  		




  65
  85
  
    

  		




  66
  86
  
    
  sei();


  		












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