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Code Issues Releases Activity

Pulse API ported.

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This commit is contained in:
Cristian Maglie 2011-11-16 23:53:46 +01:00
parent 08adc54377
commit 3b0a174f2c
2 changed files with 65 additions and 3 deletions
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7
hardware/sam/cores/sam/Arduino.h
View File

@ -35,7 +35,7 @@ extern "C"{
#define clockCyclesPerMicrosecond() ( SystemCoreClock / 1000000L )
#define clockCyclesToMicroseconds(a) ( ((a) * 1000L) / (SystemCoreClock / 1000L) )
#define microsecondsToClockCycles(a) ( ((a) * (SystemCoreClock / 1000L)) / 1000L )
#define microsecondsToClockCycles(a) ( (a) * (SystemCoreClock / 1000000L) )
#include "wiring.h"
@ -53,7 +53,7 @@ extern void loop( void ) ;
//
// These perform slightly better as macros compared to inline functions
//
#define digitalPinToPort( ulPin ) ( g_APinDescription[ulPin]->pPort )
#define digitalPinToPort( ulPin ) ( g_APinDescription[ulPin]->pPort->PIO_PDSR )
#define digitalPinToBitMask( ulPin ) ( g_APinDescription[ulPin]->dwPin )
#define digitalPinToTimer( P ) ( )
#define analogInPinToBit( P ) ( P )
@ -83,7 +83,7 @@ typedef enum _EExt_Interrupts
typedef void (*voidFuncPtr)( void ) ;
/* Define attribute */
#if defined ( __CC_ARM ) /* Keil µVision 4 */
#if defined ( __CC_ARM ) /* Keil Vision 4 */
#define WEAK (__attribute__ ((weak)))
#elif defined ( __ICCARM__ ) /* IAR Ewarm 5.41+ */
#define WEAK __weak
@ -147,6 +147,7 @@ extern const PinDescription g_APinDescription[] ;
#include "Tone.h"
#include "WMath.h"
#include "HardwareSerial.h"
#include "wiring_pulse.h"
#endif // __cplusplus
#endif // Arduino_h

61
hardware/sam/cores/sam/wiring_pulse.cpp Normal file
View File

@ -0,0 +1,61 @@
/*
Copyright (c) 2011 Arduino. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "Arduino.h"
#include "wiring_private.h"
/* Measures the length (in microseconds) of a pulse on the pin; state is HIGH
* or LOW, the type of pulse to measure. Works on pulses from 2-3 microseconds
* to 3 minutes in length, but must be called at least a few dozen microseconds
* before the start of the pulse. */
extern uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
{
// cache the port and bit of the pin in order to speed up the
// pulse width measuring loop and achieve finer resolution. calling
// digitalRead() instead yields much coarser resolution.
PinDescription p = g_APinDescription[pin];
uint32_t width = 0; // keep initialization out of time critical area
// convert the timeout from microseconds to a number of times through
// the initial loop; it takes 22 clock cycles per iteration.
uint32_t numloops = 0;
uint32_t maxloops = microsecondsToClockCycles(timeout) / 22;
// wait for any previous pulse to end
while (PIO_Get(p.pPort, PIO_INPUT, p.ulPin) == state)
if (numloops++ == maxloops)
return 0;
// wait for the pulse to start
while (PIO_Get(p.pPort, PIO_INPUT, p.ulPin) != state)
if (numloops++ == maxloops)
return 0;
// wait for the pulse to stop
while (PIO_Get(p.pPort, PIO_INPUT, p.ulPin) == state) {
if (numloops++ == maxloops)
return 0;
width++;
}
// convert the reading to microseconds. The loop has been determined
// to be 22 clock cycles long and have about 16 clocks between the edge
// and the start of the loop. There will be some error introduced by
// the interrupt handlers.
return clockCyclesToMicroseconds(width * 22 + 16);
}