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changed to pin mode to support softPwm.

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bugfix in blink.sh - wring pin
improving the maxdetect routing - a little.
gpio pins
This commit is contained in:
Gordon Henderson
2014-05-20 11:43:07 +01:00
parent f18c8f7204
commit 05e2f67e7f
11 changed files with 281 additions and 21 deletions
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49
wiringPi/softPwm.c
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@@ -1,7 +1,7 @@
/*
* softPwm.c:
* Provide 2 channels of software driven PWM.
* Copyright (c) 2012 Gordon Henderson
* Copyright (c) 2012-2014 Gordon Henderson
***********************************************************************
* This file is part of wiringPi:
* https://projects.drogon.net/raspberry-pi/wiringpi/
@@ -28,17 +28,22 @@
#include "wiringPi.h"
#include "softPwm.h"
// MAX_PINS:
// This is more than the number of Pi pins because we can actually softPwm
// pins that are on GPIO expanders. It's not that efficient and more than 1 or
// 2 pins on e.g. (SPI) mcp23s17 won't really be that effective, however...
#define MAX_PINS 1024
// The PWM Frequency is derived from the "pulse time" below. Essentially,
// the frequency is a function of the range and this pulse time.
// The total period will be range * pulse time in uS, so a pulse time
// of 100 and a range of 100 gives a period of 100 * 100 = 10,000 uS
// The total period will be range * pulse time in µS, so a pulse time
// of 100 and a range of 100 gives a period of 100 * 100 = 10,000 µS
// which is a frequency of 100Hz.
//
// It's possible to get a higher frequency by lowering the pulse time,
// however CPU uage will skyrocket as wiringPi uses a hard-loop to time
// periods under 100uS - this is because the Linux timer calls are just
// periods under 100µS - this is because the Linux timer calls are just
// accurate at all, and have an overhead.
//
// Another way to increase the frequency is to reduce the range - however
@@ -46,8 +51,9 @@
#define PULSE_TIME 100
static int marks [MAX_PINS] ;
static int range [MAX_PINS] ;
static int marks [MAX_PINS] ;
static int range [MAX_PINS] ;
static pthread_t threads [MAX_PINS] ;
int newPin = -1 ;
@@ -106,13 +112,20 @@ void softPwmWrite (int pin, int value)
/*
* softPwmCreate:
* Create a new PWM thread.
* Create a new softPWM thread.
*********************************************************************************
*/
int softPwmCreate (int pin, int initialValue, int pwmRange)
{
int res ;
pthread_t myThread ;
if (range [pin] != 0) // Already running on this pin
return -1 ;
if (range <= 0)
return -1 ;
pinMode (pin, OUTPUT) ;
digitalWrite (pin, LOW) ;
@@ -121,10 +134,30 @@ int softPwmCreate (int pin, int initialValue, int pwmRange)
range [pin] = pwmRange ;
newPin = pin ;
res = piThreadCreate (softPwmThread) ;
res = pthread_create (&myThread, NULL, softPwmThread, NULL) ;
while (newPin != -1)
delay (1) ;
threads [pin] = myThread ;
return res ;
}
/*
* softPwmStop:
* Stop an existing softPWM thread
*********************************************************************************
*/
void softPwmStop (int pin)
{
if (range [pin] != 0)
{
pthread_cancel (threads [pin]) ;
pthread_join (threads [pin], NULL) ;
range [pin] = 0 ;
digitalWrite (pin, LOW) ;
}
}