/ - Diff - Colony Scout OS - Robotics Club

Revision 812788aa

ID	812788aa5bc592cf417de345fdd8a74933d7a0c8

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.

     #PROG=avrispMKII
     PROG=stk600
     F_CPU=8000000
     F_CPU=16000000
     SRC=src/*.cpp src/ros_lib/*.cpp
     HDR=src/*.h
     FLAGS=-Isrc/ros_lib -Isrc -mmcu=$(MCU) -DF_CPU=$(F_CPU)UL -funsigned-char -Os -fpack-struct -Wall

     #include "Atmega128rfa1.h"
     #include "bom.h"
     extern "C"
+    {
-...
       void __cxa_pure_virtual(void) {}
+    }
     #define T0_KHZ 76
     #define T0_OCR (F_CPU / 1000 / T0_KHZ) // 210 ticks
     #define T0_ERROR (F_CPU / 1000 - T0_OCR*T0_KHZ) // 40 ticks/ms
     unsigned char t0_count, t0_error;
     unsigned long millis;
     int rx_start = 0, rx_end = 0;
-...
     ISR(TIMER0_COMPA_vect)
+    {
       millis++;
       bom_isr();
       // F_CPU = T0_OCR * T0_KHZ + T0_ERROR
       // every millisecond, accumulate T0_ERROR, and when it reaches T0_OCR skip
       // one iteration
       t0_count++;
       if (t0_count >= T0_KHZ) {
         t0_error += T0_ERROR;
         if (t0_error < T0_OCR) {
           t0_count = 0;
         } else {
           t0_count = -1;
           t0_error -= T0_OCR;
+        }
         millis++;
+      }
+    }
     ISR(USART0_RX_vect)
-...
       // === init time ===
       // COM0x = 0, pin OC0x not used
       // WGM0 = 2, clear timer on compare match, TOP = OCRA
       // CS0 = 3, 64 prescaler
       // CS0 = 1, no prescaler
       TCCR0A = _BV(WGM01);
       TCCR0B = _BV(CS01) | _BV(CS00);
       TCCR0B = _BV(CS00);
       // enable interrupt on compare match A
       TIMSK0 = _BV(OCIE0A);
       // 1 ms with 1/64 prescaler
       OCR0A = F_CPU / 1000 / 64;
       OCR0A = T0_OCR;
       millis = 0;
       sei();

      *   0: 1ms period
      *  Signal:
      *   38kHz pulse for 320us, then off for rest of time (680us or 1680us)
      * BOM uses timer 4 for period timing, and timer 3 for 38kHz signal
      * BOM uses timer 4 for period timing, and timer 0 for 38kHz signal
      */
     #define TIME_KHZ(khz, prescale) (F_CPU / 1000 / (khz) / (prescale))
     #define TIME_MICROS(us, prescale) (F_CPU / 1000000 * (us) / (prescale))
     typedef uint16_t sharp_msg_t;
-...
       return robot_id;
+    }
     ISR(TIMER3_COMPA_vect) {
     void bom_isr() {
       if (out_high) {
         BOM_EMIT ^= out_pin_mask;
+      }
-...
       out_high = 0;
       out_pin_mask = 0;
       // timer 3 mode CTC (clear timer on compare), TOP = OCRA
       TCCR3A = 0;
       TCCR3B = _BV(WGM32);
       TCCR3C = 0;
       // toggling at 38kHz * 2 gives 38kHz wave
       OCR3A = TIME_KHZ(38 * 2, 1);
       // enable interrupt
       TIMSK3 = _BV(OCIE3A);
       // start timer 3 at F_CPU, no prescaling
       TCCR3B |= _BV(CS30);
       // timer configuration now done in Atmega128rfa1.cpp
+    }
     static void start_38kHz_signal() {
-...
       // timer 4 mode CTC (clear timer on compare), TOP = OCRA
       TCCR4A = 0;
       TCCR4B = _BV(WGM42);
       TCCR3C = 0;
       // run interrupt immediately when timer started
       OCR4A = 0;
-...
       if (is_rising) {
         // TODO check 320us? or have 320us timeout on rising edge?
       } else {
         // uses timer 1, assuming prescale 1/8
         // timer 1 is set up by range_init()
         // uses timer 5, assuming prescale 1/8
         // timer 5 is set up by range_init()
         // this should be in units of microseconds
         int now = TCNT1 * (F_CPU / 1000000 / 8);
         int now = TCNT5 / (F_CPU / 8 / 1000000);
         if (rx->count) {
           int diff = now - rx->last_time;

scout_avr/src/bom.h
53	53	void bom_send(char dir);
54	54	int bom_get(char dir);
55	55
	56	// toggles output - should be called at around 76 kHz
	57	void bom_isr();
	58
56	59	#endif

     ros::Publisher *ptest_out;
     void debug(const char *str) {
     void debug(const char *str)
+    {
+    }
     void callback(const std_msgs::Int16& msg)
-...
     Atmega128rfa1 avr;
     void debug(const char *str) {
     void debug(const char *str)
+    {
       avr.puts(str);
+    }
-...
         now = avr.time();
         if (now > next) {
           next = now + 100;
           ultoa(now, buf, 10);
           avr.puts(buf);
           avr.puts("\r\n");
           id++;
           if (id == 0x40) {
             id = 0;
-...
           avr.puts(", ");
           utoa(range_get(1), buf, 10);
           avr.puts(buf);*/
           for (i = 0; i < 4; i++) {
           /*for (i = 0; i < 4; i++) {
             bom_send(i);
             int msg = bom_get(i);
             if (msg != BOM_NO_DATA) {
-...
               avr.puts(buf);
               avr.puts(")\r\n");
+            }
+          }
           }*/
+        }
+      }
       return 0;

     static void on_edge(int which)
+    {
       unsigned char int_high;
       // TODO centralize timer 1
       // TODO centralize timer 5
       // TODO ensure this is in microseconds even for 16MHz
       unsigned int time = TCNT1;
       unsigned int time = TCNT5;
       if (which)
+      {
-...
       // CS1 = 2, 1/8 prescaler
       // if this is changed, remember to change recv_edge in bom.cpp!
       TCCR1B = _BV(CS11);
       TCCR5B = _BV(CS51);
       range[0].value = RANGE_ERR;
       range[1].value = RANGE_ERR;

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Revision 812788aa