WebSVN - MK3Mag - Diff - Rev 18 and 19 - /branches/MK3Mag V0.14 Code Redesign Killagreg/timer0.c

 /*#######################################################################################
 MK3Mag 3D-Magnet sensor
 !!! THIS IS NOT FREE SOFTWARE !!!
 #######################################################################################*/
 // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 // + Copyright (c) 05.2008 Holger Buss
 // + Thanks to Ilja Fähnrich (P_Latzhalter)
 // + Nur für den privaten Gebrauch
 // + www.MikroKopter.com
 // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 // + Die Portierung der Software (oder Teile davon) auf andere Systeme (ausser der Hardware von www.mikrokopter.de) ist nur
 // + mit unserer Zustimmung zulässig
 // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 // + Es gilt für das gesamte Projekt (Hardware, Software, Binärfiles, Sourcecode und Dokumentation),
 // + dass eine Nutzung (auch auszugsweise) nur für den privaten (nicht-kommerziellen) Gebrauch zulässig ist.
 // + AUSNAHME: Ein bei www.mikrokopter.de erworbener vorbestückter MK3Mag darf als Baugruppe auch in kommerziellen Systemen verbaut werden
 // + Im Zweifelsfall bitte anfragen bei: info@mikrokopter.de
 // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 // + Werden Teile des Quellcodes (mit oder ohne Modifikation) weiterverwendet oder veröffentlicht,
 // + unterliegen sie auch diesen Nutzungsbedingungen und diese Nutzungsbedingungen incl. Copyright müssen dann beiliegen
 // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 // + Sollte die Software (auch auszugesweise) oder sonstige Informationen des MikroKopter-Projekts
 // + auf anderen Webseiten oder sonstigen Medien veröffentlicht werden, muss unsere Webseite "http://www.mikrokopter.de"
 // + eindeutig als Ursprung verlinkt werden
 // + Benutzung auf eigene Gefahr
 // + Wir übernehmen keinerlei Haftung für direkte oder indirekte Personen- oder Sachschäden
 // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 // + Die Funktion printf_P() unterliegt ihrer eigenen Lizenz und ist hiervon nicht betroffen
 // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 // + Redistributions of source code (with or without modifications) must retain the above copyright notice,
 // + this list of conditions and the following disclaimer.
 // +   * PORTING this software (or parts of it) to systems (other than hardware from www.mikrokopter.de) is NOT allowed
 // +   * Neither the name of the copyright holders nor the names of contributors may be used to endorse or promote products derived
 // +     from this software without specific prior written permission.
 // +   * The use of this project (hardware, software, binary files, sources and documentation) is only permittet
 // +     for non-commercial use (directly or indirectly)
 // +     Commercial use (for excample: selling of MikroKopters, selling of PCBs, assembly, ...) is only permitted
 // +     with our written permission
 // +     Exception: A preassembled MK3Mag, purchased from www.mikrokopter.de may be used as a part of commercial systems
 // +     In case of doubt please contact: info@MikroKopter.de
 // +   * If sources or documentations are redistributet on other webpages, our webpage (http://www.MikroKopter.de) must be
 // +     clearly linked as origin
 // +  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 // +  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 // +  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 // +  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 // +  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 // +  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 // +  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 // +  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 // +  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 // +  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 // +  POSSIBILITY OF SUCH DAMAGE.
 // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+#include <inttypes.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
 #include "main.h"
-volatile unsigned int CountMilliseconds = 0;
-volatile unsigned char Timer0Overflow;
-unsigned int I2C_Timeout = 0;
-unsigned int SIO_Timeout = 0;
-enum {
-  STOP             = 0,
-  CK               = 1,
-  CK8              = 2,
-  CK64             = 3,
-  CK256            = 4,
-  CK1024           = 5,
-  T0_FALLING_EDGE  = 6,
-  T0_RISING_EDGE   = 7
-};
+volatile uint16_t CountMilliseconds = 0;
+volatile uint16_t I2C_Timeout = 0;
+/*****************************************************/
+/*              Initialize Timer 0                   */
 /*****************************************************/
-SIGNAL(SIG_OVERFLOW0)
+void TIMER0_Init(void)
+{
-{
+        uint8_t sreg = SREG;
+        // disable all interrupts before reconfiguration
+        cli();
- static unsigned char cnt;
- static unsigned int cmps_cnt;
+        // set PB2 as output for the PWM used to signal compass heading
+        DDRB |= (1<<DDB2);
- TCNT0 -= 101;  // reload
+        PORTB &= ~(1<<PORTB2);
- Timer0Overflow++;
+        // Timer/Counter 0 Control Register A
- if(++cmps_cnt == 380)
- {
+        // Normal Timer Counter Mode (Bits WGM02 = 0, WGM01 = 0, WGM00 = 0)
+    // OC0A disconnected (Bits COM0A1 = 0, COM0A0 = 0)
-  PORTB |= 0x04;
+    // OC0B disconnected (Bits COM0B1 = 0, COM0B0 = 0)
-  cmps_cnt = 0;
- }
+    TCCR0A &= ~((1<<COM0A1)|(1<<COM0A0)|(1<<COM0B1)|(1<<COM0B0)|(1<<WGM01)|(1<<WGM00));
- else
- if(cmps_cnt == PwmHeading)
+        // Timer/Counter 0 Control Register B
+        // set clock devider for timer 0 to SYSKLOCK/8 = 8MHz / 8 = 1MHz
- {
+        // i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz
+        // hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz
+        // divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)
-  PORTB &= ~0x04;
+        TCCR0B &= ~((1<<FOC0A)|(1<<FOC0B)|(1<<WGM02)|(1<<CS02));
+    TCCR0B = (1<<CS01)|(0<<CS00);
- }
+        // init Timer/Counter 0 Register
- if(!--cnt)
+    TCNT0 = 0;
-  {
-   cnt = 10;
+        // Timer/Counter 0 Interrupt Mask Register
-   CountMilliseconds += 1;
+        // enable timer overflow interrupt only
-   if(I2C_Timeout) I2C_Timeout--;
+        TIMSK0 &= ~((1<<OCIE0B)|(1<<OCIE0A));
+        TIMSK0 |= (1<<TOIE0);
    if(SIO_Timeout) SIO_Timeout--;
+        SREG = sreg;
-  }
+}
+// -----------------------------------------------------------------------
+ISR(TIMER0_OVF_vect)
+{
+        static uint8_t cnt;
+        static uint16_t cmps_cnt;
+        // reload timer register so that overflow occurs after 100 increments at 1 MHz
+        // resulting in a calling rate of this ISR of 10kHz or 0.1 ms.
+        TCNT0 -= 101;
-void Timer0_Init(void)
+        // disable PWM when bad compass heading value
+        if(Heading < 0)
+        {
+                PORTB &= ~(PORTB2);
+                cmps_cnt = 0;
+        }
+        else
+        {
-{
+                // if a periode of 38.0 ms is over
+                if(++cmps_cnt >= 380)
+                {
+                        // set PWM out to high
+                        PORTB |= PORTB2;
+                        // reset periode counter
+                        cmps_cnt = 0;
+                }
+                // if the delay in 0.1 ms is equal to Heading + 10
+                else if(cmps_cnt >= (Heading + 10))
+                {
+                        // set PWM out to low
+                        PORTB &= ~(PORTB2);
+                }
+        }
+        if(!--cnt)
+        {
+                // every 10th run (1kHz or 1ms)
- TCCR0B = TIMER_TEILER;  // Starten des Timers
+                cnt = 10;
+                CountMilliseconds++;
-// TCNT0 = 100;  // reload
+                if(I2C_Timeout) I2C_Timeout--;
  TIM0_START;
- TIMER2_INT_ENABLE;
+}
+// -----------------------------------------------------------------------
 uint16_t SetDelay (uint16_t t)
-unsigned int SetDelay(unsigned int t)
+{
   return(CountMilliseconds + t - 1);
+}
-  return(CountMilliseconds + t - 1);
 // -----------------------------------------------------------------------
+int8_t CheckDelay(uint16_t t)
-char CheckDelay (unsigned int t)
+{
-{
+        return(((t - CountMilliseconds) & 0x8000) >> 8); // check sign bit
   return(((t - CountMilliseconds) & 0x8000) >> 8);
+// -----------------------------------------------------------------------
+void Delay_ms(uint16_t wait)
+{

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(root)/branches/MK3Mag V0.14 Code Redesign Killagreg/timer0.c - Rev 18 → 19