#define SPEED_UP A0
#define SPEED_DOWN A1
#define PWM_MAX_DUTY 255
#define PWM_MIN_DUTY 50
#define PWM_START_DUTY 100
byte bldc_step = 0, motor_speed;
unsigned int i;
void setup() {
DDRD |= 0x38; // Configure pins 3, 4 and 5 as outputs
PORTD = 0x00;
DDRB |= 0x0E; // Configure pins 9, 10 and 11 as outputs
PORTB = 0x31;
// Timer1 module setting: set clock source to clkI/O / 1 (no prescaling)
TCCR1A = 0;
TCCR1B = 0x01;
// Timer2 module setting: set clock source to clkI/O / 1 (no prescaling)
TCCR2A = 0;
TCCR2B = 0x01;
// Analog comparator setting
ACSR = 0x10; // Disable and clear (flag bit) analog comparator interrupt
pinMode(SPEED_UP, INPUT_PULLUP);
pinMode(SPEED_DOWN, INPUT_PULLUP);
}
// Analog comparator ISR
ISR (ANALOG_COMP_vect) {
// BEMF debounce
for(i = 0; i < 10; i++) {
if(bldc_step & 1){
if(!(ACSR & 0x20)) i -= 1;
}
else {
if((ACSR & 0x20)) i -= 1;
}
}
bldc_move();
bldc_step++;
bldc_step %= 6;
}
void bldc_move(){ // BLDC motor commutation function
switch(bldc_step){
case 0:
AH_BL();
BEMF_C_RISING();
break;
case 1:
AH_CL();
BEMF_B_FALLING();
break;
case 2:
BH_CL();
BEMF_A_RISING();
break;
case 3:
BH_AL();
BEMF_C_FALLING();
break;
case 4:
CH_AL();
BEMF_B_RISING();
break;
case 5:
CH_BL();
BEMF_A_FALLING();
break;
}
}
void loop() {
SET_PWM_DUTY(PWM_START_DUTY); // Setup starting PWM with duty cycle = PWM_START_DUTY
i = 5000;
// Motor start
while(i > 100) {
delayMicroseconds(i);
bldc_move();
bldc_step++;
bldc_step %= 6;
i = i - 20;
}
motor_speed = PWM_START_DUTY;
ACSR |= 0x08; // Enable analog comparator interrupt
while(1) {
while(!(digitalRead(SPEED_UP)) && motor_speed < PWM_MAX_DUTY){
motor_speed++;
SET_PWM_DUTY(motor_speed);
delay(100);
}
while(!(digitalRead(SPEED_DOWN)) && motor_speed > PWM_MIN_DUTY){
motor_speed--;
SET_PWM_DUTY(motor_speed);
delay(100);
}
}
}
void BEMF_A_RISING(){
ADCSRB = (0 << ACME); // Select AIN1 as comparator negative input
ACSR |= 0x03; // Set interrupt on rising edge
}
void BEMF_A_FALLING(){
ADCSRB = (0 << ACME); // Select AIN1 as comparator negative input
ACSR &= ~0x01; // Set interrupt on falling edge
}
void BEMF_B_RISING(){
ADCSRA = (0 << ADEN); // Disable the ADC module
ADCSRB = (1 << ACME);
ADMUX = 2; // Select analog channel 2 as comparator negative input
ACSR |= 0x03;
}
void BEMF_B_FALLING(){
ADCSRA = (0 << ADEN); // Disable the ADC module
ADCSRB = (1 << ACME);
ADMUX = 2; // Select analog channel 2 as comparator negative input
ACSR &= ~0x01;
}
void BEMF_C_RISING(){
ADCSRA = (0 << ADEN); // Disable the ADC module
ADCSRB = (1 << ACME);
ADMUX = 3; // Select analog channel 3 as comparator negative input
ACSR |= 0x03;
}
void BEMF_C_FALLING(){
ADCSRA = (0 << ADEN); // Disable the ADC module
ADCSRB = (1 << ACME);
ADMUX = 3; // Select analog channel 3 as comparator negative input
ACSR &= ~0x01;
}
void AH_BL(){
PORTB = 0x04;
PORTD &= ~0x18;
PORTD |= 0x20;
TCCR1A = 0; // Turn pin 11 (OC2A) PWM ON (pin 9 & pin 10 OFF)
TCCR2A = 0x81; //
}
void AH_CL(){
PORTB = 0x02;
PORTD &= ~0x18;
PORTD |= 0x20;
TCCR1A = 0; // Turn pin 11 (OC2A) PWM ON (pin 9 & pin 10 OFF)
TCCR2A = 0x81; //
}
void BH_CL(){
PORTB = 0x02;
PORTD &= ~0x28;
PORTD |= 0x10;
TCCR2A = 0; // Turn pin 10 (OC1B) PWM ON (pin 9 & pin 11 OFF)
TCCR1A = 0x21; //
}
void BH_AL(){
PORTB = 0x08;
PORTD &= ~0x28;
PORTD |= 0x10;
TCCR2A = 0; // Turn pin 10 (OC1B) PWM ON (pin 9 & pin 11 OFF)
TCCR1A = 0x21; //
}
void CH_AL(){
PORTB = 0x08;
PORTD &= ~0x30;
PORTD |= 0x08;
TCCR2A = 0; // Turn pin 9 (OC1A) PWM ON (pin 10 & pin 11 OFF)
TCCR1A = 0x81; //
}
void CH_BL(){
PORTB = 0x04;
PORTD &= ~0x30;
PORTD |= 0x08;
TCCR2A = 0; // Turn pin 9 (OC1A) PWM ON (pin 10 & pin 11 OFF)
TCCR1A = 0x81; //
}
void SET_PWM_DUTY(byte duty){
if(duty < PWM_MIN_DUTY)
duty = PWM_MIN_DUTY;
if(duty > PWM_MAX_DUTY)
duty = PWM_MAX_DUTY;
OCR1A = duty; // Set pin 9 PWM duty cycle
OCR1B = duty; // Set pin 10 PWM duty cycle
OCR2A = duty; // Set pin 11 PWM duty cycle
} Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!
OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.
#include <stdio.h>
int main()
{
char name[50];
printf("Enter name:");
scanf("%s", name);
printf("Hello %s \n" , name );
return 0;
}
C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.
When ever you want to perform a set of operations based on a condition if-else is used.
if(conditional-expression) {
// code
} else {
// code
}
You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to if-else-if ladder.
switch(conditional-expression) {
case value1:
// code
break; // optional
case value2:
// code
break; // optional
...
default:
// code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
// code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while(condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.
data-type array-name[size];
data-type array-name[size][size];
Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.
Two types of functions are present in C
Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,
User defined functions are the ones which are written by the programmer based on the requirement.
return_type function_name(parameters);
function_name (parameters)
return_type function_name(parameters) {
//code
}