ardupilot/libraries/AP_HAL_Linux/RCOutput_Navio.cpp

146 lines
3.9 KiB
C++

#include <AP_HAL.h>
#include "GPIO.h"
#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_NAVIO
#include "RCOutput_Navio.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <math.h>
using namespace Linux;
#define PWM_CHAN_COUNT 13
#define PCA9685_OUTPUT_ENABLE RPI_GPIO_27
static const AP_HAL::HAL& hal = AP_HAL_BOARD_DRIVER;
void LinuxRCOutput_Navio::init(void* machtnicht)
{
_i2c_sem = hal.i2c->get_semaphore();
if (_i2c_sem == NULL) {
hal.scheduler->panic(PSTR("PANIC: RCOutput_Navio did not get "
"valid I2C semaphore!"));
return; // never reached
}
// Set the initial frequency
set_freq(0, 50);
/* Enable PCA9685 PWM */
enable_pin = hal.gpio->channel(PCA9685_OUTPUT_ENABLE);
enable_pin->mode(HAL_GPIO_OUTPUT);
enable_pin->write(0);
}
void LinuxRCOutput_Navio::set_freq(uint32_t chmask, uint16_t freq_hz)
{
if (!_i2c_sem->take(10)) {
return;
}
// Put PCA9685 to sleep (required to write prescaler)
hal.i2c->writeRegister(PCA9685_ADDRESS, PCA9685_RA_MODE1, PCA9685_MODE1_SLEEP_BIT);
// Calculate and write prescale value to match frequency
uint8_t prescale = round(24576000.f / 4096.f / freq_hz) - 1;
hal.i2c->writeRegister(PCA9685_ADDRESS, PCA9685_RA_PRE_SCALE, prescale);
// Reset all channels
uint8_t data[4] = {0x00, 0x00, 0x00, 0x00};
hal.i2c->writeRegisters(PCA9685_ADDRESS, PCA9685_RA_ALL_LED_ON_L, 4, data);
// Enable external clocking
hal.i2c->writeRegister(PCA9685_ADDRESS, PCA9685_RA_MODE1,
PCA9685_MODE1_SLEEP_BIT | PCA9685_MODE1_EXTCLK_BIT);
// Restart the device to apply new settings and enable auto-incremented write
hal.i2c->writeRegister(PCA9685_ADDRESS, PCA9685_RA_MODE1,
PCA9685_MODE1_RESTART_BIT | PCA9685_MODE1_AI_BIT);
_frequency = freq_hz;
_i2c_sem->give();
}
uint16_t LinuxRCOutput_Navio::get_freq(uint8_t ch)
{
return _frequency;
}
void LinuxRCOutput_Navio::enable_ch(uint8_t ch)
{
}
void LinuxRCOutput_Navio::disable_ch(uint8_t ch)
{
write(ch, 0);
}
void LinuxRCOutput_Navio::write(uint8_t ch, uint16_t period_us)
{
if(ch >= PWM_CHAN_COUNT){
return;
}
if (!_i2c_sem->take_nonblocking()) {
return;
}
uint16_t length;
if (period_us == 0)
length = 0;
else
length = round((period_us * 4096) / (1000000.f / _frequency)) - 1;
uint8_t data[2] = {length & 0xFF, length >> 8};
uint8_t status = hal.i2c->writeRegisters(PCA9685_ADDRESS,
PCA9685_RA_LED0_OFF_L + 4 * (ch + 3),
2,
data);
_i2c_sem->give();
}
void LinuxRCOutput_Navio::write(uint8_t ch, uint16_t* period_us, uint8_t len)
{
for (int i = 0; i < len; i++)
write(ch + i, period_us[i]);
}
uint16_t LinuxRCOutput_Navio::read(uint8_t ch)
{
if (!_i2c_sem->take_nonblocking()) {
return 0;
}
uint8_t data[4] = {0x00, 0x00, 0x00, 0x00};
hal.i2c->readRegisters(PCA9685_ADDRESS,
PCA9685_RA_LED0_ON_L + 4 * (ch + 3),
4,
data);
uint16_t length = data[2] + ((data[3] & 0x0F) << 8);
uint16_t period_us = (length + 1) * (1000000.f / _frequency) / 4096.f;
_i2c_sem->give();
return length == 0 ? 0 : period_us;
}
void LinuxRCOutput_Navio::read(uint16_t* period_us, uint8_t len)
{
for (int i = 0; i < len; i++)
period_us[i] = read(0 + i);
}
#endif // CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_NAVIO