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#include "stm32.h"
#include "interrupt.h"
#include "thread.h"
#include "time.h"
#include "ppmsum.h"
#include "i2c.h"
#include "ahrs.h"
#include "telemetry.h"
#include "usart.h"
#include "xbee.h"
#include "gps.h"
template<class T>
inline void saturate(T& var, T absmax) {
if(var > absmax) {
var = absmax;
} else if(var < -absmax) {
var = -absmax;
}
}
template<class T>
inline T limit(T var, T min, T max) {
if(var < min) {
return min;
} else if(var > max) {
return max;
} else {
return var;
}
}
class PID {
private:
uint16_t Kp, Ki, Kd;
int16_t last;
int32_t accum;
public:
PID(uint16_t p, uint16_t i, uint16_t d) : Kp(p), Ki(i), Kd(d), last(0), accum(0) {}
int16_t update(int16_t error) {
// P
int32_t corr_p = Kp * error;
// I
accum += Ki * error;
int32_t corr_i = accum;
// D
int32_t corr_d = Kd * (error - last);
last = error;
return (corr_p + corr_i + corr_d) >> 16;
}
};
I2C i2c;
AHRS ahrs(i2c);
volatile uint16_t motors[4];
GPS gps;
void gps_thread_main() {
while(1) {
P<GPSMsg> msg = gps.read();
if(msg->n < 128) {
xbee_send(2, msg->n, msg->buf);
}
}
}
uint32_t gps_stack[256];
Thread gps_thread(gps_stack, sizeof(gps_stack), gps_thread_main);
int main() {
// Initialize system timer.
STK.LOAD = 72000000 / 8 / 1000; // 1000 Hz.
STK.CTRL = 0x03;
RCC.enable(RCC.AFIO);
RCC.enable(RCC.IOPA);
RCC.enable(RCC.IOPB);
GPIOA.CRL = 0x4400bbbb;
GPIOA.CRH = 0x444444b4;
GPIOB.CRL = 0xff444434;
GPIOB.CRH = 0x44444444;
GPIOB.ODR = 1 << 1;
RCC.enable(RCC.DMA1);
RCC.enable(RCC.ADC1);
// Give all hardware enough time to initialize.
Time::sleep(200);
i2c.enable();
ahrs.init();
PPMSum ppmsum;
ppmsum.enable();
RCC.enable(RCC.TIM2);
TIM2.PSC = 72;
TIM2.ARR = 5000;
TIM2.CCER = 0x1111;
TIM2.CCMR1 = 0x6868;
TIM2.CCMR2 = 0x6868;
TIM2.CR1 = 0x05;
PID pid_pitch(6000, 0, 0);
PID pid_roll(6000, 0, 0);
PID pid_yaw(6000, 0, 0);
usart_enable();
gps.enable();
telemetry_thread.start();
//gps_thread.start();
while(1) {
// Wait for a new update.
while(!(TIM2.SR & 0x01)) {
Thread::yield();
}
TIM2.SR = 0;
// Update AHRS.
ahrs.update();
// Update filter.
int16_t throttle = ppmsum.channels[2] - 1000;
int16_t pitch = pid_pitch.update((ppmsum.channels[1] - 1500) * 1 - ahrs.gyro.x);
int16_t roll = pid_roll.update((ppmsum.channels[0] - 1500) * 1 - ahrs.gyro.y);
int16_t yaw = pid_yaw.update((ppmsum.channels[3] - 1500) * -1 - ahrs.gyro.z);
int16_t max = throttle > 250 ? 250 : throttle;
saturate(pitch, max);
saturate(roll, max);
saturate(yaw, max);
// Generate motor mix.
motors[0] = limit(throttle + pitch - roll + yaw, 0, 1000);
motors[1] = limit(throttle - pitch - roll - yaw, 0, 1000);
motors[2] = limit(throttle - pitch + roll + yaw, 0, 1000);
motors[3] = limit(throttle + pitch + roll - yaw, 0, 1000);
TIM2.CCR1 = 1000 + motors[0];
TIM2.CCR2 = 1000 + motors[1];
TIM2.CCR3 = 1000 + motors[2];
TIM2.CCR4 = 1000 + motors[3];
}
}
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