void setup() {
}
#include <Wire.h> //Include the Wire.h library so we can communicate with the gyro.
#include <EEPROM.h> //Include the EEPROM.h library so we can store information onto the EEPROM
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//PID gain and limit settings
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
float pid_p_gain_roll = 1.3; //Gain setting for the roll P-controller
float pid_i_gain_roll = 0.04; //Gain setting for the roll I-controller
float pid_d_gain_roll = 18.0; //Gain setting for the roll D-controller
int pid_max_roll = 400; //Maximum output of the PID-controller (+/-)
float pid_p_gain_pitch = pid_p_gain_roll; //Gain setting for the pitch P-controller.
float pid_i_gain_pitch = pid_i_gain_roll; //Gain setting for the pitch I-controller.
float pid_d_gain_pitch = pid_d_gain_roll; //Gain setting for the pitch D-controller.
int pid_max_pitch = pid_max_roll; //Maximum output of the PID-controller (+/-)
float pid_p_gain_yaw = 4.0; //Gain setting for the pitch P-controller. //4.0
float pid_i_gain_yaw = 0.02; //Gain setting for the pitch I-controller. //0.02
float pid_d_gain_yaw = 0.0; //Gain setting for the pitch D-controller.
int pid_max_yaw = 400; //Maximum output of the PID-controller (+/-)
boolean auto_level = true; //Auto level on (true) or off (false)
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Declaring global variables
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
byte last_channel_1, last_channel_2, last_channel_3, last_channel_4;
byte eeprom_data[36];
byte highByte, lowByte;
int receiver_input_channel_1, receiver_input_channel_2, receiver_input_channel_3, receiver_input_channel_4;
int counter_channel_1, counter_channel_2, counter_channel_3, counter_channel_4, loop_counter;
int esc_1, esc_2, esc_3, esc_4;
int throttle, battery_voltage;
int cal_int, start, gyro_address;
int receiver_input[5];
int temperature;
int acc_axis[4], gyro_axis[4];
float roll_level_adjust, pitch_level_adjust;
long acc_x, acc_y, acc_z, acc_total_vector;
unsigned long timer_channel_1, timer_channel_2, timer_channel_3, timer_channel_4, esc_timer, esc_loop_timer;
unsigned long timer_1, timer_2, timer_3, timer_4, current_time;
unsigned long loop_timer;
double gyro_pitch, gyro_roll, gyro_yaw;
double gyro_axis_cal[4];
float pid_error_temp;
float pid_i_mem_roll, pid_roll_setpoint, gyro_roll_input, pid_output_roll, pid_last_roll_d_error;
float pid_i_mem_pitch, pid_pitch_setpoint, gyro_pitch_input, pid_output_pitch, pid_last_pitch_d_error;
float pid_i_mem_yaw, pid_yaw_setpoint, gyro_yaw_input, pid_output_yaw, pid_last_yaw_d_error;
float angle_roll_acc, angle_pitch_acc, angle_pitch, angle_roll;
boolean gyro_angles_set;
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Setup routine
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void setup(){
//Serial.begin(57600);
//Copy the EEPROM data for fast access data.
for(start = 0; start <= 35; start++)eeprom_data[start] = EEPROM.read(start);
start = 0; //Set start back to zero.
gyro_address = eeprom_data[32]; //Store the gyro address in the variable.
Wire.begin(); //Start the I2C as master.
TWBR = 12; //Set the I2C clock speed to 400kHz.
//Arduino (Atmega) pins default to inputs, so they don't need to be explicitly declared as inputs.
DDRD |= B11110000; //Configure digital poort 4, 5, 6 and 7 as output.
DDRB |= B00110000; //Configure digital poort 12 and 13 as output.
//Use the led on the Arduino for startup indication.
digitalWrite(12,HIGH); //Turn on the warning led.
//Check the EEPROM signature to make sure that the setup program is executed.
while(eeprom_data[33] != 'J' || eeprom_data[34] != 'M' || eeprom_data[35] != 'B')delay(10);
//The flight controller needs the MPU-6050 with gyro and accelerometer
//If setup is completed without MPU-6050 stop the flight controller program
if(eeprom_data[31] == 2 || eeprom_data[31] == 3)delay(10);
set_gyro_registers(); //Set the specific gyro registers.
for (cal_int = 0; cal_int < 1250 ; cal_int ++){ //Wait 5 seconds before continuing.
PORTD |= B11110000; //Set digital poort 4, 5, 6 and 7 high.
delayMicroseconds(1000); //Wait 1000us.
PORTD &= B00001111; //Set digital poort 4, 5, 6 and 7 low.
delayMicroseconds(3000); //Wait 3000us.
}
//Let's take multiple gyro data samples so we can determine the average gyro offset (calibration).
for (cal_int = 0; cal_int < 2000 ; cal_int ++){ //Take 2000 readings for calibration.
if(cal_int % 15 == 0)digitalWrite(12, !digitalRead(12)); //Change the led status to indicate calibration.
gyro_signalen(); //Read the gyro output.
gyro_axis_cal[1] += gyro_axis[1]; //Ad roll value to gyro_roll_cal.
gyro_axis_cal[2] += gyro_axis[2]; //Ad pitch value to gyro_pitch_cal.
gyro_axis_cal[3] += gyro_axis[3]; //Ad yaw value to gyro_yaw_cal.
//We don't want the esc's to be beeping annoyingly. So let's give them a 1000us puls while calibrating the gyro.
PORTD |= B11110000; //Set digital poort 4, 5, 6 and 7 high.
delayMicroseconds(1000); //Wait 1000us.
PORTD &= B00001111; //Set digital poort 4, 5, 6 and 7 low.
delay(3); //Wait 3 milliseconds before the next loop.
}
//Now that we have 2000 measures, we need to devide by 2000 to get the average gyro offset.
gyro_axis_cal[1] /= 2000; //Divide the roll total by 2000.
gyro_axis_cal[2] /= 2000; //Divide the pitch total by 2000.
gyro_axis_cal[3] /= 2000; //Divide the yaw total by 2000.
PCICR |= (1 << PCIE0); //Set PCIE0 to enable PCMSK0 scan.
PCMSK0 |= (1 << PCINT0); //Set PCINT0 (digital input 8) to trigger an interrupt on state change.
PCMSK0 |= (1 << PCINT1); //Set PCINT1 (digital input 9)to trigger an interrupt on state change.
PCMSK0 |= (1 << PCINT2); //Set PCINT2 (digital input 10)to trigger an interrupt on state change.
PCMSK0 |= (1 << PCINT3); //Set PCINT3 (digital input 11)to trigger an interrupt on state change.
//Wait until the receiver is active and the throtle is set to the lower position.
while(receiver_input_channel_3 < 990 || receiver_input_channel_3 > 1020 || receiver_input_channel_4 < 1400){
receiver_input_channel_3 = convert_receiver_channel(3); //Convert the actual receiver signals for throttle to the standard 1000 - 2000us
receiver_input_channel_4 = convert_receiver_channel(4); //Convert the actual receiver signals for yaw to the standard 1000 - 2000us
start ++; //While waiting increment start whith every loop.
//We don't want the esc's to be beeping annoyingly. So let's give them a 1000us puls while waiting for the receiver inputs.
PORTD |= B11110000; //Set digital poort 4, 5, 6 and 7 high.
delayMicroseconds(1000); //Wait 1000us.
PORTD &= B00001111; //Set digital poort 4, 5, 6 and 7 low.
delay(3); //Wait 3 milliseconds before the next loop.
if(start == 125){ //Every 125 loops (500ms).
digitalWrite(12, !digitalRead(12)); //Change the led status.
start = 0; //Start again at 0.
}
}
start = 0; //Set start back to 0.
//Load the battery voltage to the battery_voltage variable.
//65 is the voltage compensation for the diode.
//12.6V equals ~5V @ Analog 0.
//12.6V equals 1023 analogRead(0).
//1260 / 1023 = 1.2317.
//The variable battery_voltage holds 1050 if the battery voltage is 10.5V.
battery_voltage = (analogRead(0) + 65) * 1.2317;
loop_timer = micros(); //Set the timer for the next loop.
//When everything is done, turn off the led.
digitalWrite(12,LOW); //Turn off the warning led.
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Main program loop
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void loop(){
//65.5 = 1 deg/sec (check the datasheet of the MPU-6050 for more information).
gyro_roll_input = (gyro_roll_input * 0.7) + ((gyro_roll / 65.5) * 0.3); //Gyro pid input is deg/sec.
gyro_pitch_input = (gyro_pitch_input * 0.7) + ((gyro_pitch / 65.5) * 0.3);//Gyro pid input is deg/sec.
gyro_yaw_input = (gyro_yaw_input * 0.7) + ((gyro_yaw / 65.5) * 0.3); //Gyro pid input is deg/sec.
//Gyro angle calculations
//0.0000611 = 1 / (250Hz / 65.5)
angle_pitch += gyro_pitch * 0.0000611; //Calculate the traveled pitch angle and add this to the angle_pitch variable.
angle_roll += gyro_roll * 0.0000611; //Calculate the traveled roll angle and add this to the angle_roll variable.
//0.000001066 = 0.0000611 * (3.142(PI) / 180degr) The Arduino sin function is in radians
angle_pitch -= angle_roll * sin(gyro_yaw * 0.000001066); //If the IMU has yawed transfer the roll angle to the pitch angel.
angle_roll += angle_pitch * sin(gyro_yaw * 0.000001066); //If the IMU has yawed transfer the pitch angle to the roll angel.
//Accelerometer angle calculations
acc_total_vector = sqrt((acc_x*acc_x)+(acc_y*acc_y)+(acc_z*acc_z)); //Calculate the total accelerometer vector.
if(abs(acc_y) < acc_total_vector){ //Prevent the asin function to produce a NaN
angle_pitch_acc = asin((float)acc_y/acc_total_vector)* 57.296; //Calculate the pitch angle.
}
if(abs(acc_x) < acc_total_vector){ //Prevent the asin function to produce a NaN
angle_roll_acc = asin((float)acc_x/acc_total_vector)* -57.296; //Calculate the roll angle.
}
//Place the MPU-6050 spirit level and note the values in the following two lines for calibration.
angle_pitch_acc -= 0.0; //Accelerometer calibration value for pitch.
angle_roll_acc -= 0.0; //Accelerometer calibration value for roll.
angle_pitch = angle_pitch * 0.9996 + angle_pitch_acc * 0.0004; //Correct the drift of the gyro pitch angle with the accelerometer pitch angle.
angle_roll = angle_roll * 0.9996 + angle_roll_acc * 0.0004; //Correct the drift of the gyro roll angle with the accelerometer roll angle.
pitch_level_adjust = angle_pitch * 15; //Calculate the pitch angle correction
roll_level_adjust = angle_roll * 15; //Calculate the roll angle correction
if(!auto_level){ //If the quadcopter is not in auto-level mode
pitch_level_adjust = 0; //Set the pitch angle correction to zero.
roll_level_adjust = 0; //Set the roll angle correcion to zero.
}
//For starting the motors: throttle low and yaw left (step 1).
if(receiver_input_channel_3 < 1050 && receiver_input_channel_4 < 1050)start = 1;
//When yaw stick is back in the center position start the motors (step 2).
if(start == 1 && receiver_input_channel_3 < 1050 && receiver_input_channel_4 > 1450){
start = 2;
angle_pitch = angle_pitch_acc; //Set the gyro pitch angle equal to the accelerometer pitch angle when the quadcopter is started.
angle_roll = angle_roll_acc; //Set the gyro roll angle equal to the accelerometer roll angle when the quadcopter is started.
gyro_angles_set = true; //Set the IMU started flag.
//Reset the PID controllers for a bumpless start.
pid_i_mem_roll = 0;
pid_last_roll_d_error = 0;
pid_i_mem_pitch = 0;
pid_last_pitch_d_error = 0;
pid_i_mem_yaw = 0;
pid_last_yaw_d_error = 0;
}
//Stopping the motors: throttle low and yaw right.
if(start == 2 && receiver_input_channel_3 < 1050 && receiver_input_channel_4 > 1950)start = 0;
//The PID set point in degrees per second is determined by the roll receiver input.
//In the case of deviding by 3 the max roll rate is aprox 164 degrees per second ( (500-8)/3 = 164d/s ).
pid_roll_setpoint = 0;
//We need a little dead band of 16us for better results.
if(receiver_input_channel_1 > 1508)pid_roll_setpoint = receiver_input_channel_1 - 1508;
else if(receiver_input_channel_1 < 1492)pid_roll_setpoint = receiver_input_channel_1 - 1492;
pid_roll_setpoint -= roll_level_adjust; //Subtract the angle correction from the standardized receiver roll input value.
pid_roll_setpoint /= 3.0; //Divide the setpoint for the PID roll controller by 3 to get angles in degrees.
//The PID set point in degrees per second is determined by the pitch receiver input.
//In the case of deviding by 3 the max pitch rate is aprox 164 degrees per second ( (500-8)/3 = 164d/s ).
pid_pitch_setpoint = 0;
//We need a little dead band of 16us for better results.
if(receiver_input_channel_2 > 1508)pid_pitch_setpoint = receiver_input_channel_2 - 1508;
else if(receiver_input_channel_2 < 1492)pid_pitch_setpoint = receiver_input_channel_2 - 1492;
pid_pitch_setpoint -= pitch_level_adjust; //Subtract the angle correction from the standardized receiver pitch input value.
pid_pitch_setpoint /= 3.0; //Divide the setpoint for the PID pitch controller by 3 to get angles in degrees.
//The PID set point in degrees per second is determined by the yaw receiver input.
//In the case of deviding by 3 the max yaw rate is aprox 164 degrees per second ( (500-8)/3 = 164d/s ).
pid_yaw_setpoint = 0;
//We need a little dead band of 16us for better results.
if(receiver_input_channel_3 > 1050){ //Do not yaw when turning off the motors.
if(receiver_input_channel_4 > 1508)pid_yaw_setpoint = (receiver_input_channel_4 - 1508)/3.0;
else if(receiver_input_channel_4 < 1492)pid_yaw_setpoint = (receiver_input_channel_4 - 1492)/3.0;
}
calculate_pid(); //PID inputs are known. So we can calculate the pid output.
//The battery voltage is needed for compensation.
//A complementary filter is used to reduce noise.
//0.09853 = 0.08 * 1.2317.
battery_voltage = battery_voltage * 0.92 + (analogRead(0) + 65) * 0.09853;
//Turn on the led if battery voltage is to low.
if(battery_voltage < 1000 && battery_voltage > 600)digitalWrite(12, HIGH);
throttle = receiver_input_channel_3; //We need the throttle signal as a base signal.
if (start == 2){ //The motors are started.
if (throttle > 1800) throttle = 1800; //We need some room to keep full control at full throttle.
esc_1 = throttle - pid_output_pitch + pid_output_roll - pid_output_yaw; //Calculate the pulse for esc 1 (front-right - CCW)
esc_2 = throttle + pid_output_pitch + pid_output_roll + pid_output_yaw; //Calculate the pulse for esc 2 (rear-right - CW)
esc_3 = throttle + pid_output_pitch - pid_output_roll - pid_output_yaw; //Calculate the pulse for esc 3 (rear-left - CCW)
esc_4 = throttle - pid_output_pitch - pid_output_roll + pid_output_yaw; //Calculate the pulse for esc 4 (front-left - CW)
if (battery_voltage < 1240 && battery_voltage > 800){ //Is the battery connected?
esc_1 += esc_1 * ((1240 - battery_voltage)/(float)3500); //Compensate the esc-1 pulse for voltage drop.
esc_2 += esc_2 * ((1240 - battery_voltage)/(float)3500); //Compensate the esc-2 pulse for voltage drop.
esc_3 += esc_3 * ((1240 - battery_voltage)/(float)3500); //Compensate the esc-3 pulse for voltage drop.
esc_4 += esc_4 * ((1240 - battery_voltage)/(float)3500); //Compensate the esc-4 pulse for voltage drop.
}
if (esc_1 < 1200) esc_1 = 1200; //Keep the motors running.
if (esc_2 < 1200) esc_2 = 1200; //Keep the motors running.
if (esc_3 < 1200) esc_3 = 1200; //Keep the motors running.
if (esc_4 < 1200) esc_4 = 1200; //Keep the motors running.
if(esc_1 > 2000)esc_1 = 2000; //Limit the esc-1 pulse to 2000us.
if(esc_2 > 2000)esc_2 = 2000; //Limit the esc-2 pulse to 2000us.
if(esc_3 > 2000)esc_3 = 2000; //Limit the esc-3 pulse to 2000us.
if(esc_4 > 2000)esc_4 = 2000; //Limit the esc-4 pulse to 2000us.
}
else{
esc_1 = 1000; //If start is not 2 keep a 1000us pulse for ess-1.
esc_2 = 1000; //If start is not 2 keep a 1000us pulse for ess-2.
esc_3 = 1000; //If start is not 2 keep a 1000us pulse for ess-3.
esc_4 = 1000; //If start is not 2 keep a 1000us pulse for ess-4.
}
if(micros() - loop_timer > 4050)digitalWrite(12, HIGH); //Turn on the LED if the loop time exceeds 4050us.
//All the information for controlling the motor's is available.
//The refresh rate is 250Hz. That means the esc's need there pulse every 4ms.
while(micros() - loop_timer < 4000); //We wait until 4000us are passed.
loop_timer = micros(); //Set the timer for the next loop.
PORTD |= B11110000; //Set digital outputs 4,5,6 and 7 high.
timer_channel_1 = esc_1 + loop_timer; //Calculate the time of the faling edge of the esc-1 pulse.
timer_channel_2 = esc_2 + loop_timer; //Calculate the time of the faling edge of the esc-2 pulse.
timer_channel_3 = esc_3 + loop_timer; //Calculate the time of the faling edge of the esc-3 pulse.
timer_channel_4 = esc_4 + loop_timer; //Calculate the time of the faling edge of the esc-4 pulse.
//There is always 1000us of spare time. So let's do something usefull that is very time consuming.
//Get the current gyro and receiver data and scale it to degrees per second for the pid calculations.
gyro_signalen();
while(PORTD >= 16){ //Stay in this loop until output 4,5,6 and 7 are low.
esc_loop_timer = micros(); //Read the current time.
if(timer_channel_1 <= esc_loop_timer)PORTD &= B11101111; //Set digital output 4 to low if the time is expired.
if(timer_channel_2 <= esc_loop_timer)PORTD &= B11011111; //Set digital output 5 to low if the time is expired.
if(timer_channel_3 <= esc_loop_timer)PORTD &= B10111111; //Set digital output 6 to low if the time is expired.
if(timer_channel_4 <= esc_loop_timer)PORTD &= B01111111; //Set digital output 7 to low if the time is expired.
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//This routine is called every time input 8, 9, 10 or 11 changed state. This is used to read the receiver signals.
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
ISR(PCINT0_vect){
current_time = micros();
//Channel 1=========================================
if(PINB & B00000001){ //Is input 8 high?
if(last_channel_1 == 0){ //Input 8 changed from 0 to 1.
last_channel_1 = 1; //Remember current input state.
timer_1 = current_time; //Set timer_1 to current_time.
}
}
else if(last_channel_1 == 1){ //Input 8 is not high and changed from 1 to 0.
last_channel_1 = 0; //Remember current input state.
receiver_input[1] = current_time - timer_1; //Channel 1 is current_time - timer_1.
}
//Channel 2=========================================
if(PINB & B00000010 ){ //Is input 9 high?
if(last_channel_2 == 0){ //Input 9 changed from 0 to 1.
last_channel_2 = 1; //Remember current input state.
timer_2 = current_time; //Set timer_2 to current_time.
}
}
else if(last_channel_2 == 1){ //Input 9 is not high and changed from 1 to 0.
last_channel_2 = 0; //Remember current input state.
receiver_input[2] = current_time - timer_2; //Channel 2 is current_time - timer_2.
}
//Channel 3=========================================
if(PINB & B00000100 ){ //Is input 10 high?
if(last_channel_3 == 0){ //Input 10 changed from 0 to 1.
last_channel_3 = 1; //Remember current input state.
timer_3 = current_time; //Set timer_3 to current_time.
}
}
else if(last_channel_3 == 1){ //Input 10 is not high and changed from 1 to 0.
last_channel_3 = 0; //Remember current input state.
receiver_input[3] = current_time - timer_3; //Channel 3 is current_time - timer_3.
}
//Channel 4=========================================
if(PINB & B00001000 ){ //Is input 11 high?
if(last_channel_4 == 0){ //Input 11 changed from 0 to 1.
last_channel_4 = 1; //Remember current input state.
timer_4 = current_time; //Set timer_4 to current_time.
}
}
else if(last_channel_4 == 1){ //Input 11 is not high and changed from 1 to 0.
last_channel_4 = 0; //Remember current input state.
receiver_input[4] = current_time - timer_4; //Channel 4 is current_time - timer_4.
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Subroutine for reading the gyro
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void gyro_signalen(){
//Read the MPU-6050
if(eeprom_data[31] == 1){
Wire.beginTransmission(gyro_address); //Start communication with the gyro.
Wire.write(0x3B); //Start reading @ register 43h and auto increment with every read.
Wire.endTransmission(); //End the transmission.
Wire.requestFrom(gyro_address,14); //Request 14 bytes from the gyro.
receiver_input_channel_1 = convert_receiver_channel(1); //Convert the actual receiver signals for pitch to the standard 1000 - 2000us.
receiver_input_channel_2 = convert_receiver_channel(2); //Convert the actual receiver signals for roll to the standard 1000 - 2000us.
receiver_input_channel_3 = convert_receiver_channel(3); //Convert the actual receiver signals for throttle to the standard 1000 - 2000us.
receiver_input_channel_4 = convert_receiver_channel(4); //Convert the actual receiver signals for yaw to the standard 1000 - 2000us.
while(Wire.available() < 14); //Wait until the 14 bytes are received.
acc_axis[1] = Wire.read()<<8|Wire.read(); //Add the low and high byte to the acc_x variable.
acc_axis[2] = Wire.read()<<8|Wire.read(); //Add the low and high byte to the acc_y variable.
acc_axis[3] = Wire.read()<<8|Wire.read(); //Add the low and high byte to the acc_z variable.
temperature = Wire.read()<<8|Wire.read(); //Add the low and high byte to the temperature variable.
gyro_axis[1] = Wire.read()<<8|Wire.read(); //Read high and low part of the angular data.
gyro_axis[2] = Wire.read()<<8|Wire.read(); //Read high and low part of the angular data.
gyro_axis[3] = Wire.read()<<8|Wire.read(); //Read high and low part of the angular data.
}
if(cal_int == 2000){
gyro_axis[1] -= gyro_axis_cal[1]; //Only compensate after the calibration.
gyro_axis[2] -= gyro_axis_cal[2]; //Only compensate after the calibration.
gyro_axis[3] -= gyro_axis_cal[3]; //Only compensate after the calibration.
}
gyro_roll = gyro_axis[eeprom_data[28] & 0b00000011]; //Set gyro_roll to the correct axis that was stored in the EEPROM.
if(eeprom_data[28] & 0b10000000)gyro_roll *= -1; //Invert gyro_roll if the MSB of EEPROM bit 28 is set.
gyro_pitch = gyro_axis[eeprom_data[29] & 0b00000011]; //Set gyro_pitch to the correct axis that was stored in the EEPROM.
if(eeprom_data[29] & 0b10000000)gyro_pitch *= -1; //Invert gyro_pitch if the MSB of EEPROM bit 29 is set.
gyro_yaw = gyro_axis[eeprom_data[30] & 0b00000011]; //Set gyro_yaw to the correct axis that was stored in the EEPROM.
if(eeprom_data[30] & 0b10000000)gyro_yaw *= -1; //Invert gyro_yaw if the MSB of EEPROM bit 30 is set.
acc_x = acc_axis[eeprom_data[29] & 0b00000011]; //Set acc_x to the correct axis that was stored in the EEPROM.
if(eeprom_data[29] & 0b10000000)acc_x *= -1; //Invert acc_x if the MSB of EEPROM bit 29 is set.
acc_y = acc_axis[eeprom_data[28] & 0b00000011]; //Set acc_y to the correct axis that was stored in the EEPROM.
if(eeprom_data[28] & 0b10000000)acc_y *= -1; //Invert acc_y if the MSB of EEPROM bit 28 is set.
acc_z = acc_axis[eeprom_data[30] & 0b00000011]; //Set acc_z to the correct axis that was stored in the EEPROM.
if(eeprom_data[30] & 0b10000000)acc_z *= -1; //Invert acc_z if the MSB of EEPROM bit 30 is set.
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//Subroutine for calculating pid outputs
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void calculate_pid(){
//Roll calculations
pid_error_temp = gyro_roll_input - pid_roll_setpoint;
pid_i_mem_roll += pid_i_gain_roll * pid_error_temp;
if(pid_i_mem_roll > pid_max_roll)pid_i_mem_roll = pid_max_roll;
else if(pid_i_mem_roll < pid_max_roll * -1)pid_i_mem_roll = pid_max_roll * -1;
pid_output_roll = pid_p_gain_roll * pid_error_temp + pid_i_mem_roll + pid_d_gain_roll * (pid_error_temp - pid_last_roll_d_error);
if(pid_output_roll > pid_max_roll)pid_output_roll = pid_max_roll;
else if(pid_output_roll < pid_max_roll * -1)pid_output_roll = pid_max_roll * -1;
pid_last_roll_d_error = pid_error_temp;
//Pitch calculations
pid_error_temp = gyro_pitch_input - pid_pitch_setpoint;
pid_i_mem_pitch += pid_i_gain_pitch * pid_error_temp;
if(pid_i_mem_pitch > pid_max_pitch)pid_i_mem_pitch = pid_max_pitch;
else if(pid_i_mem_pitch < pid_max_pitch * -1)pid_i_mem_pitch = pid_max_pitch * -1;
pid_output_pitch = pid_p_gain_pitch * pid_error_temp + pid_i_mem_pitch + pid_d_gain_pitch * (pid_error_temp - pid_last_pitch_d_error);
if(pid_output_pitch > pid_max_pitch)pid_output_pitch = pid_max_pitch;
else if(pid_output_pitch < pid_max_pitch * -1)pid_output_pitch = pid_max_pitch * -1;
pid_last_pitch_d_error = pid_error_temp;
//Yaw calculations
pid_error_temp = gyro_yaw_input - pid_yaw_setpoint;
pid_i_mem_yaw += pid_i_gain_yaw * pid_error_temp;
if(pid_i_mem_yaw > pid_max_yaw)pid_i_mem_yaw = pid_max_yaw;
else if(pid_i_mem_yaw < pid_max_yaw * -1)pid_i_mem_yaw = pid_max_yaw * -1;
pid_output_yaw = pid_p_gain_yaw * pid_error_temp + pid_i_mem_yaw + pid_d_gain_yaw * (pid_error_temp - pid_last_yaw_d_error);
if(pid_output_yaw > pid_max_yaw)pid_output_yaw = pid_max_yaw;
else if(pid_output_yaw < pid_max_yaw * -1)pid_output_yaw = pid_max_yaw * -1;
pid_last_yaw_d_error = pid_error_temp;
}
//This part converts the actual receiver signals to a standardized 1000 1500 2000 microsecond value.
//The stored data in the EEPROM is used.
int convert_receiver_channel(byte function){
byte channel, reverse; //First we declare some local variables
int low, center, high, actual;
int difference;
channel = eeprom_data[function + 23] & 0b00000111; //What channel corresponds with the specific function
if(eeprom_data[function + 23] & 0b10000000)reverse = 1; //Reverse channel when most significant bit is set
else reverse = 0; //If the most significant is not set there is no reverse
actual = receiver_input[channel]; //Read the actual receiver value for the corresponding function
low = (eeprom_data[channel * 2 + 15] << 8) | eeprom_data[channel * 2 + 14]; //Store the low value for the specific receiver input channel
center = (eeprom_data[channel * 2 - 1] << 8) | eeprom_data[channel * 2 - 2]; //Store the center value for the specific receiver input channel
high = (eeprom_data[channel * 2 + 7] << 8) | eeprom_data[channel * 2 + 6]; //Store the high value for the specific receiver input channel
if(actual < center){ //The actual receiver value is lower than the center value
if(actual < low)actual = low; //Limit the lowest value to the value that was detected during setup
difference = ((long)(center - actual) * (long)500) / (center - low); //Calculate and scale the actual value to a 1000 - 2000us value
if(reverse == 1)return 1500 + difference; //If the channel is reversed
else return 1500 - difference; //If the channel is not reversed
}
else if(actual > center){ //The actual receiver value is higher than the center value
if(actual > high)actual = high; //Limit the lowest value to the value that was detected during setup
difference = ((long)(actual - center) * (long)500) / (high - center); //Calculate and scale the actual value to a 1000 - 2000us value
if(reverse == 1)return 1500 - difference; //If the channel is reversed
else return 1500 + difference; //If the channel is not reversed
}
else return 1500;
}
void set_gyro_registers(){
//Setup the MPU-6050
if(eeprom_data[31] == 1){
Wire.beginTransmission(gyro_address); //Start communication with the address found during search.
Wire.write(0x6B); //We want to write to the PWR_MGMT_1 register (6B hex)
Wire.write(0x00); //Set the register bits as 00000000 to activate the gyro
Wire.endTransmission(); //End the transmission with the gyro.
Wire.beginTransmission(gyro_address); //Start communication with the address found during search.
Wire.write(0x1B); //We want to write to the GYRO_CONFIG register (1B hex)
Wire.write(0x08); //Set the register bits as 00001000 (500dps full scale)
Wire.endTransmission(); //End the transmission with the gyro
Wire.beginTransmission(gyro_address); //Start communication with the address found during search.
Wire.write(0x1C); //We want to write to the ACCEL_CONFIG register (1A hex)
Wire.write(0x10); //Set the register bits as 00010000 (+/- 8g full scale range)
Wire.endTransmission(); //End the transmission with the gyro
//Let's perform a random register check to see if the values are written correct
Wire.beginTransmission(gyro_address); //Start communication with the address found during search
Wire.write(0x1B); //Start reading @ register 0x1B
Wire.endTransmission(); //End the transmission
Wire.requestFrom(gyro_address, 1); //Request 1 bytes from the gyro
while(Wire.available() < 1); //Wait until the 6 bytes are received
if(Wire.read() != 0x08){ //Check if the value is 0x08
digitalWrite(12,HIGH); //Turn on the warning led
while(1)delay(10); //Stay in this loop for ever
}
Wire.beginTransmission(gyro_address); //Start communication with the address found during search
Wire.write(0x1A); //We want to write to the CONFIG register (1A hex)
Wire.write(0x03); //Set the register bits as 00000011 (Set Digital Low Pass Filter to ~43Hz)
Wire.endTransmission(); //End the transmission with the gyro
}
}
void loop() {
}
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