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Topic: Wie DmxSimple Timer ändern? (Read 629 times) previous topic - next topic

Auron88

Nov 20, 2012, 09:56 pm Last Edit: Nov 20, 2012, 09:59 pm by Auron88 Reason: 1
Hallo,
auf meinem Arduino Mega 2560 sitzen zwei shields:
-  IR-Shield: http://www.linksprite.com/product/showproduct.php?lang=en&id=64
                 mit der Ken Shirriff Blog library: http://www.arcfn.com/2009/08/multi-protocol-infrared-remote-library.html
-  DMX-Shield: http://code.google.com/p/tinkerit/wiki/DmxSimple

Nun scheint es so, als ob die beiden sich gegenseitig blockieren. Hardwaretechnisch alles gelöst, aber ich glaube beide greifen auf den TIMER 2 in den Libs zu..
Denn wenn ich irrecv.enableIRIn() auskommentiere sendet das DMX Signal wieder.

Nun zu meiner Frage:
1. Könnte ich mit meiner Vermutung richtig liegen?
Oder hat jemand einen anderen Vorschlag? (bin kein großer Programmierer und im Mikrocontrollerbereich erst recht nicht :-/)
2. Kann ich die lib vom DMX so ändern, dass sie auf einen anderen, freien TIMER vom Arduino Mega 2560 zugreift?
Code: [Select]
/**
* DmxSimple - A simple interface to DMX.
*
* Copyright (c) 2008-2009 Peter Knight, Tinker.it! All rights reserved.
*/
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include "pins_arduino.h"

#include "Arduino.h"
#include "DmxSimple.h"

/** dmxBuffer contains a software copy of all the DMX channels.
 */
volatile uint8_t dmxBuffer[DMX_SIZE];
static uint16_t dmxMax = 16; /* Default to sending the first 16 channels */
static uint8_t dmxStarted = 0;
static uint16_t dmxState = 0;

static volatile uint8_t *dmxPort;
static uint8_t dmxBit = 0;
static uint8_t dmxPin = 6; // Defaults to output on pin 3 to support Tinker.it! DMX shield

void dmxBegin();
void dmxEnd();
void dmxSendByte(volatile uint8_t);
void dmxWrite(int,uint8_t);
void dmxMaxChannel(int);

/* TIMER2 has a different register mapping on the ATmega8.
* The modern chips (168, 328P, 1280) use identical mappings.
*/
#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega2560__) || defined(__AVR_ATmega168P__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega1280__)
#define TIMER2_INTERRUPT_ENABLE() TIMSK2 |= _BV(TOIE2)
#define TIMER2_INTERRUPT_DISABLE() TIMSK2 &= ~_BV(TOIE2)
#elif defined(__AVR_ATmega8__)
#define TIMER2_INTERRUPT_ENABLE() TIMSK |= _BV(TOIE2)
#define TIMER2_INTERRUPT_DISABLE() TIMSK &= ~_BV(TOIE2)
#else
#define TIMER2_INTERRUPT_ENABLE()
#define TIMER2_INTERRUPT_DISABLE()
/* Produce an appropriate message to aid error reporting on nonstandard
* platforms such as Teensy.
*/
#warning "DmxSimple does not support this CPU"
#endif


/** Initialise the DMX engine
*/
void dmxBegin()
{
 dmxStarted = 1;

 // Set up port pointers for interrupt routine
 dmxPort = portOutputRegister(digitalPinToPort(dmxPin));
 dmxBit = digitalPinToBitMask(dmxPin);

 // Set DMX pin to output
 pinMode(dmxPin,OUTPUT);

 // Initialise DMX frame interrupt
 //
 // Presume Arduino has already set Timer2 to 64 prescaler,
 // Phase correct PWM mode
 // So the overflow triggers every 64*510 clock cycles
 // Which is 510 DMX bit periods at 16MHz,
 //          255 DMX bit periods at 8MHz,
 //          637 DMX bit periods at 20MHz
 TIMER2_INTERRUPT_ENABLE();
}

/** Stop the DMX engine
* Turns off the DMX interrupt routine
*/
void dmxEnd()
{
 TIMER2_INTERRUPT_DISABLE();
 dmxStarted = 0;
 dmxMax = 0;
}

/** Transmit a complete DMX byte
* We have no serial port for DMX, so everything is timed using an exact
* number of instruction cycles.
*
* Really suggest you don't touch this function.
*/
void dmxSendByte(volatile uint8_t value)
{
 uint8_t bitCount, delCount;
 __asm__ volatile (
   "cli\n"
   "ld __tmp_reg__,%a[dmxPort]\n"
   "and __tmp_reg__,%[outMask]\n"
   "st %a[dmxPort],__tmp_reg__\n"
   "ldi %[bitCount],11\n" // 11 bit intervals per transmitted byte
   "rjmp bitLoop%=\n"     // Delay 2 clock cycles.
 "bitLoop%=:\n"\
   "ldi %[delCount],%[delCountVal]\n"
 "delLoop%=:\n"
   "nop\n"
   "dec %[delCount]\n"
   "brne delLoop%=\n"
   "ld __tmp_reg__,%a[dmxPort]\n"
   "and __tmp_reg__,%[outMask]\n"
   "sec\n"
   "ror %[value]\n"
   "brcc sendzero%=\n"
   "or __tmp_reg__,%[outBit]\n"
 "sendzero%=:\n"
   "st %a[dmxPort],__tmp_reg__\n"
   "dec %[bitCount]\n"
   "brne bitLoop%=\n"
   "sei\n"
   :
     [bitCount] "=&d" (bitCount),
     [delCount] "=&d" (delCount)
   :
     [dmxPort] "e" (dmxPort),
     [outMask] "r" (~dmxBit),
     [outBit] "r" (dmxBit),
     [delCountVal] "M" (F_CPU/1000000-3),
     [value] "r" (value)
 );
}

/** DmxSimple interrupt routine
* Transmit a chunk of DMX signal every timer overflow event.
*
* The full DMX transmission takes too long, but some aspects of DMX timing
* are flexible. This routine chunks the DMX signal, only sending as much as
* it's time budget will allow.
*
* This interrupt routine runs with interrupts enabled most of the time.
* With extremely heavy interrupt loads, it could conceivably interrupt its
* own routine, so the TIMER2 interrupt is disabled for the duration of
* the service routine.
*/
ISR(TIMER2_OVF_vect,ISR_NOBLOCK) {

 // Prevent this interrupt running recursively
 TIMER2_INTERRUPT_DISABLE();

 uint16_t bitsLeft = F_CPU / 31372; // DMX Bit periods per timer tick
 bitsLeft >>=2; // 25% CPU usage
 while (1) {
   if (dmxState == 0) {
     // Next thing to send is reset pulse and start code
     // which takes 35 bit periods
     uint8_t i;
     if (bitsLeft < 35) break;
     bitsLeft-=35;
     *dmxPort &= ~dmxBit;
     for (i=0; i<11; i++) _delay_us(8);
     *dmxPort |= dmxBit;
     _delay_us(8);
     dmxSendByte(0);
   } else {
     // Now send a channel which takes 11 bit periods
     if (bitsLeft < 11) break;
     bitsLeft-=11;
     dmxSendByte(dmxBuffer[dmxState-1]);
   }
   // Successfully completed that stage - move state machine forward
   dmxState++;
   if (dmxState > dmxMax) {
     dmxState = 0; // Send next frame
     break;
   }
 }
 
 // Enable interrupts for the next transmission chunk
 TIMER2_INTERRUPT_ENABLE();
}

void dmxWrite(int channel, uint8_t value) {
 if (!dmxStarted) dmxBegin();
 if ((channel > 0) && (channel <= DMX_SIZE)) {
   if (value<0) value=0;
   if (value>255) value=255;
   dmxMax = max((unsigned)channel, dmxMax);
   dmxBuffer[channel-1] = value;
 }
}

void dmxMaxChannel(int channel) {
 if (channel <=0) {
   // End DMX transmission
   dmxEnd();
   dmxMax = 0;
 } else {
   dmxMax = min(channel, DMX_SIZE);
   if (!dmxStarted) dmxBegin();
 }
}


/* C++ wrapper */


/** Set output pin
* @param pin Output digital pin to use
*/
void DmxSimpleClass::usePin(uint8_t pin) {
 dmxPin = pin;
 if (dmxStarted && (pin != dmxPin)) {
   dmxEnd();
   dmxBegin();
 }
}

/** Set DMX maximum channel
* @param channel The highest DMX channel to use
*/
void DmxSimpleClass::maxChannel(int channel) {
 dmxMaxChannel(channel);
}

/** Write to a DMX channel
* @param address DMX address in the range 1 - 512
*/
void DmxSimpleClass::write(int address, uint8_t value)
{
dmxWrite(address, value);
}
DmxSimpleClass DmxSimple;


Ist das sehr aufwendig? Ich kenne mich mit Interrupts, Timern und Countern bis lang gar nicht aus.

Vielen Dank für die Hilfe
Grüße
Roman

BerndJM

Hi,

bei der Timer Geschichte kann ich dir zwar nicht direkt helfen, aber hier gibt es auch noch eine ganz nette DMX-Library, vielleicht geht's ja mit der.

Grüßle Bernd
Theoretisch gibt es keinen Unterschied zwischen Theorie und Praxis ...

pylon

Quote
1. Könnte ich mit meiner Vermutung richtig liegen?


Ja.

Quote
2. Kann ich die lib vom DMX so ändern, dass sie auf einen anderen, freien TIMER vom Arduino Mega 2560 zugreift?


Ist nur ein schneller Hack, aber könnte funktionieren (DmxSimple.cpp):

Code: [Select]
/**
* DmxSimple - A simple interface to DMX.
*
* Copyright (c) 2008-2009 Peter Knight, Tinker.it! All rights reserved.
*/
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include "pins_arduino.h"

#include "wiring.h"
#include "DmxSimple.h"

/** dmxBuffer contains a software copy of all the DMX channels.
  */
volatile uint8_t dmxBuffer[DMX_SIZE];
static uint16_t dmxMax = 16; /* Default to sending the first 16 channels */
static uint8_t dmxStarted = 0;
static uint16_t dmxState = 0;

static volatile uint8_t *dmxPort;
static uint8_t dmxBit = 0;
static uint8_t dmxPin = 3; // Defaults to output on pin 3 to support Tinker.it! DMX shield

void dmxBegin();
void dmxEnd();
void dmxSendByte(volatile uint8_t);
void dmxWrite(int,uint8_t);
void dmxMaxChannel(int);

/* TIMER2 has a different register mapping on the ATmega8.
* The modern chips (168, 328P, 1280) use identical mappings.
*/
#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega168P__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega1280__)
#define TIMER1_INTERRUPT_ENABLE() TIMSK1 |= _BV(TOIE1)
#define TIMER1_INTERRUPT_DISABLE() TIMSK1 &= ~_BV(TOIE1)
#elif defined(__AVR_ATmega8__)
#define TIMER1_INTERRUPT_ENABLE() TIMSK |= _BV(TOIE1)
#define TIMER1_INTERRUPT_DISABLE() TIMSK &= ~_BV(TOIE1)
#else
#define TIMER1_INTERRUPT_ENABLE()
#define TIMER1_INTERRUPT_DISABLE()
/* Produce an appropriate message to aid error reporting on nonstandard
* platforms such as Teensy.
*/
#warning "DmxSimple does not support this CPU"
#endif


/** Initialise the DMX engine
*/
void dmxBegin()
{
  dmxStarted = 1;

  // Set up port pointers for interrupt routine
  dmxPort = portOutputRegister(digitalPinToPort(dmxPin));
  dmxBit = digitalPinToBitMask(dmxPin);

  // Set DMX pin to output
  pinMode(dmxPin,OUTPUT);

  // Initialise DMX frame interrupt
  //
  // Timer1 prescaler 64 and phase correct pwm
  TCCR1A = 0x01;
  TCCR1B = 0x03;
  TCCR1C = 0x00;  //
  // Presume Arduino has already set Timer2 to 64 prescaler,
  // Phase correct PWM mode
  // So the overflow triggers every 64*510 clock cycles
  // Which is 510 DMX bit periods at 16MHz,
  //          255 DMX bit periods at 8MHz,
  //          637 DMX bit periods at 20MHz
  TIMER1_INTERRUPT_ENABLE();
}

/** Stop the DMX engine
* Turns off the DMX interrupt routine
*/
void dmxEnd()
{
  TIMER1_INTERRUPT_DISABLE();
  dmxStarted = 0;
  dmxMax = 0;
}

/** Transmit a complete DMX byte
* We have no serial port for DMX, so everything is timed using an exact
* number of instruction cycles.
*
* Really suggest you don't touch this function.
*/
void dmxSendByte(volatile uint8_t value)
{
  uint8_t bitCount, delCount;
  __asm__ volatile (
    "cli\n"
    "ld __tmp_reg__,%a[dmxPort]\n"
    "and __tmp_reg__,%[outMask]\n"
    "st %a[dmxPort],__tmp_reg__\n"
    "ldi %[bitCount],11\n" // 11 bit intervals per transmitted byte
    "rjmp bitLoop%=\n"     // Delay 2 clock cycles.
  "bitLoop%=:\n"\
    "ldi %[delCount],%[delCountVal]\n"
  "delLoop%=:\n"
    "nop\n"
    "dec %[delCount]\n"
    "brne delLoop%=\n"
    "ld __tmp_reg__,%a[dmxPort]\n"
    "and __tmp_reg__,%[outMask]\n"
    "sec\n"
    "ror %[value]\n"
    "brcc sendzero%=\n"
    "or __tmp_reg__,%[outBit]\n"
  "sendzero%=:\n"
    "st %a[dmxPort],__tmp_reg__\n"
    "dec %[bitCount]\n"
    "brne bitLoop%=\n"
    "sei\n"
    :
      [bitCount] "=&d" (bitCount),
      [delCount] "=&d" (delCount)
    :
      [dmxPort] "e" (dmxPort),
      [outMask] "r" (~dmxBit),
      [outBit] "r" (dmxBit),
      [delCountVal] "M" (F_CPU/1000000-3),
      [value] "r" (value)
  );
}

/** DmxSimple interrupt routine
* Transmit a chunk of DMX signal every timer overflow event.
*
* The full DMX transmission takes too long, but some aspects of DMX timing
* are flexible. This routine chunks the DMX signal, only sending as much as
* it's time budget will allow.
*
* This interrupt routine runs with interrupts enabled most of the time.
* With extremely heavy interrupt loads, it could conceivably interrupt its
* own routine, so the TIMER2 interrupt is disabled for the duration of
* the service routine.
*/
ISR(TIMER1_OVF_vect,ISR_NOBLOCK) {

  // Prevent this interrupt running recursively
  TIMER1_INTERRUPT_DISABLE();

  uint16_t bitsLeft = F_CPU / 31372; // DMX Bit periods per timer tick
  bitsLeft >>=2; // 25% CPU usage
  while (1) {
    if (dmxState == 0) {
      // Next thing to send is reset pulse and start code
      // which takes 35 bit periods
      uint8_t i;
      if (bitsLeft < 35) break;
      bitsLeft-=35;
      *dmxPort &= ~dmxBit;
      for (i=0; i<11; i++) _delay_us(8);
      *dmxPort |= dmxBit;
      _delay_us(8);
      dmxSendByte(0);
    } else {
      // Now send a channel which takes 11 bit periods
      if (bitsLeft < 11) break;
      bitsLeft-=11;
      dmxSendByte(dmxBuffer[dmxState-1]);
    }
    // Successfully completed that stage - move state machine forward
    dmxState++;
    if (dmxState > dmxMax) {
      dmxState = 0; // Send next frame
      break;
    }
  }
 
  // Enable interrupts for the next transmission chunk
  TIMER1_INTERRUPT_ENABLE();
}

void dmxWrite(int channel, uint8_t value) {
  if (!dmxStarted) dmxBegin();
  if ((channel > 0) && (channel <= DMX_SIZE)) {
    if (value<0) value=0;
    if (value>255) value=255;
    dmxMax = max((unsigned)channel, dmxMax);
    dmxBuffer[channel-1] = value;
  }
}

void dmxMaxChannel(int channel) {
  if (channel <=0) {
    // End DMX transmission
    dmxEnd();
    dmxMax = 0;
  } else {
    dmxMax = min(channel, DMX_SIZE);
    if (!dmxStarted) dmxBegin();
  }
}


/* C++ wrapper */


/** Set output pin
* @param pin Output digital pin to use
*/
void DmxSimpleClass::usePin(uint8_t pin) {
  dmxPin = pin;
  if (dmxStarted && (pin != dmxPin)) {
    dmxEnd();
    dmxBegin();
  }
}

/** Set DMX maximum channel
* @param channel The highest DMX channel to use
*/
void DmxSimpleClass::maxChannel(int channel) {
  dmxMaxChannel(channel);
}

/** Write to a DMX channel
* @param address DMX address in the range 1 - 512
*/
void DmxSimpleClass::write(int address, uint8_t value)
{
dmxWrite(address, value);
}
DmxSimpleClass DmxSimple;

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