CPiE3Programs

Article Index

Page 7 of 21

Chapter 9

Page 151

#include <bcm2835.h>

int main(int argc, char **argv)

{

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(2);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 2);

bcm2835_pwm_set_data(0, 1);

return (0);

}

Page 152

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char **argv)

{

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_gpio_fsel(13, BCM2835_GPIO_FSEL_ALT0);

bcm2835_pwm_set_clock(2);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 2);

bcm2835_pwm_set_data(0, 1);

bcm2835_pwm_set_mode(1, 1, 1);

bcm2835_pwm_set_range(1, 8);

bcm2835_pwm_set_data(1, 2);

return (EXIT_SUCCESS);

}

Page 153

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char **argv)

{

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(2);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 256);

for (;;)

{

bcm2835_pwm_set_data(0, 16);

bcm2835_delayMicroseconds((int)26.666 * 8);

bcm2835_pwm_set_data(0, 128);

bcm2835_delayMicroseconds((int)26.666 * 8);

}

return (EXIT_SUCCESS);

}

Page 155

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char** argv) {

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(2);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 256);

for (;;) {

for (int i = 0; i < 256; i = i + 10) {

bcm2835_pwm_set_data(0, i);

bcm2835_delayMicroseconds(100);

}

return (EXIT_SUCCESS);

}

Page 156

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char **argv)

{

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(2);

bcm2835_pwm_set_mode(0, 1, 1);

int C = 34091;

bcm2835_pwm_set_range(0, C);

bcm2835_pwm_set_data(0, C / 2);

return (EXIT_SUCCESS);

}

Page 158

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char **argv){

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(2);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 1024);

int w = 1;

int inc = 1;

for (;;)

{

bcm2835_pwm_set_data(0, w);

w = w + inc;

if (w > 1024 || w <= 0)

inc = -inc;

bcm2835_delayMicroseconds(5000);

}

return (EXIT_SUCCESS);

}

bcm2835_delayMicroseconds(5000);

}

return (EXIT_SUCCESS);

}

Page 159

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char **argv)

{

if (!bcm2835_init())

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(2);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 1024);

int w = 0;

int inc = 1;

for (;;)

{

bcm2835_pwm_set_data(0, w * w * w);

w = w + inc;

if (w > 10 || w <= 0)

inc = -inc;

bcm2835_delayMicroseconds(50000);

}

return (EXIT_SUCCESS);

}

Page 160

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char **argv)

{

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(2);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 1024);

int w = 0;

int inc = 1;

for (;;)

{

bcm2835_pwm_set_data(0, (w * w * w) >> 3);

w = w + inc;

if (w > 20 || w <= 0)

inc = -inc;

bcm2835_delayMicroseconds(50000);

}

return (EXIT_SUCCESS);

}

Page 163

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char **argv)

{

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(375);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 1024);

for (;;)

{

bcm2835_pwm_set_data(0, 25);

bcm2835_delayMicroseconds(2000000);

bcm2835_pwm_set_data(0, 50);

bcm2835_delayMicroseconds(2000000);

bcm2835_pwm_set_data(0, 128);

bcm2835_delayMicroseconds(2000000);

}

return (EXIT_SUCCESS);

}

Page 164

#include <stdio.h>

#include <stdlib.h>

#include <bcm2835.h>

int main(int argc, char **argv)

{

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock(375);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 1024);

for (;;)

{

bcm2835_pwm_set_data(0, 52 * 0 / 180 + 920);

bcm2835_delayMicroseconds(2000000);

bcm2835_pwm_set_data(0, 52 * 90 / 180 + 920);

bcm2835_delayMicroseconds(2000000);

bcm2835_pwm_set_data(0, 52 * 180 / 180 + 920);

bcm2835_delayMicroseconds(2000000);

}

return (EXIT_SUCCESS);

}

Page 166

Function only - needs to run as root.

void bcm2835_pwm_set_clock_source(

uint32_t source,

uint32_t divisorI,

uint32_t divisorF)

{

divisorI &= 0xfff;

divisorF &= 0xfff;

source &= 0xf;

uint8_t mask = bcm2835_peri_read(bcm2835_clk + BCM2835_PWMCLK_CNTL) & 0xffffffef;

bcm2835_peri_write(bcm2835_clk + BCM2835_PWMCLK_CNTL, BCM2835_PWM_PASSWRD | mask);

while ((bcm2835_peri_read(bcm2835_clk + BCM2835_PWMCLK_CNTL) & 0x80) != 0)

{

};

bcm2835_peri_write(bcm2835_clk + BCM2835_PWMCLK_DIV, BCM2835_PWM_PASSWRD | (divisorI << 12) | divisorF);

bcm2835_peri_write(bcm2835_clk + BCM2835_PWMCLK_CNTL, BCM2835_PWM_PASSWRD | source | 0x200);

bcm2835_peri_write(bcm2835_clk + BCM2835_PWMCLK_CNTL, BCM2835_PWM_PASSWRD | 0x210 | source);

}

Page 168

This needs to be run as root.

#include <stdio.h>

#include <stdlib.h>

#include <sys/mman.h>

#include <bcm2835.h>

void bcm2835_pwm_set_clock_source(uint32_t source,uint32_t divisorI,uint32_t divisorF)

{

divisorI &= 0xfff;

divisorF &= 0xfff;

source &= 0xf;

uint8_t mask = bcm2835_peri_read(bcm2835_clk + BCM2835_PWMCLK_CNTL) & 0xffffffef;

bcm2835_peri_write(bcm2835_clk + BCM2835_PWMCLK_CNTL, BCM2835_PWM_PASSWRD | mask);

while ((bcm2835_peri_read(bcm2835_clk + BCM2835_PWMCLK_CNTL) & 0x80) != 0)

{

};

bcm2835_peri_write(bcm2835_clk + BCM2835_PWMCLK_DIV, BCM2835_PWM_PASSWRD | (divisorI << 12) | divisorF);

bcm2835_peri_write(bcm2835_clk + BCM2835_PWMCLK_CNTL, BCM2835_PWM_PASSWRD | source | 0x200);

bcm2835_peri_write(bcm2835_clk + BCM2835_PWMCLK_CNTL, BCM2835_PWM_PASSWRD | 0x210 | source);

}

int main(int argc, char **argv)

{

if (!bcm2835_init())

return 1;

bcm2835_gpio_fsel(18, BCM2835_GPIO_FSEL_ALT5);

bcm2835_pwm_set_clock_source(6, 2, 0);

bcm2835_pwm_set_mode(0, 1, 1);

bcm2835_pwm_set_range(0, 256);

int i;

for (;;)

{

for (i = 0; i < 256; i = i + 10)

{

bcm2835_pwm_set_data(0, i);

bcm2835_delayMicroseconds(2);

}

return (EXIT_SUCCESS);

}

Article Index

Chapter 9

Page 151

Page 152

Page 153

Page 155

Page 156

Page 158

Page 159

Page 160

Page 163

Page 164

Page 166

Page 168

Main Menu