Type 'double' is not assignable to 'int'

hye ppl.this is the code.i removed the timer so the code is easier.can u tell me is this will function like its suppose to.and my problem is with the compiler, Type ‘double’ is not assignable to ‘int’.i dont know how to fix this.can anyone help?

#include “WProgram.h”

//Global variables to be used
int x, y;
double lastx;
double lasty;
long timer;
int idle_timer;
int threshold;
int cross_count;
int in_tune;
int average_val;
int pitch_diff;

int upper_bound;
int lower_bound;
int avg_cross;
int avg_counter;
int avg_upper;
int avg_lower;
double a, b;

int timer_divide;
int divide_by;

int string_select;
int select_pin_val;

int analogPin = 0; // analog to digital pin for signal input

int led_high = 13; // this LED will show user if a string’s pitch is too high
int led_ok = 12; // this LED will show user if a string’s pitch is correct
int led_low = 11; // this LED will show user if a string’s pitch is too low

// these pins will light up to show which string the Atmega is comparing values for
int led_e4 = 10;
int led_b3 = 9;
int led_g3 = 8;
int led_d3 = 7;
int led_a2 = 6;
int led_e2 = 5;

int button_pin = 3; // input pin for user using a button to switch strings
int servoPin = 2; // control pin for servo motor

void setup()
{
// Set up timer 1 to generate an interrupt every 1 microsecond
x = 0;
lastx = 0;
y = 0;
lasty = 0;

timer = 0;
cross_count = 0;
avg_cross = 0;
avg_counter = 0;
string_select = 0;

//Set the input and output pins
pinMode(button_pin, INPUT);
pinMode(servoPin, OUTPUT);
pinMode(led_high, OUTPUT);
pinMode(led_ok, OUTPUT);
pinMode(led_low, OUTPUT);
pinMode(led_e4, OUTPUT);
pinMode(led_b3, OUTPUT);
pinMode(led_g3, OUTPUT);
pinMode(led_d3, OUTPUT);
pinMode(led_a2, OUTPUT);
pinMode(led_e2, OUTPUT);

Serial.begin(9600); // Opens serial port, sets data rate to 9600 bps
}

// Nothing is done in the Arduino loop, since timing is off.
void loop()
{
timer++;
idle_timer++;

// Read button press to determine which string is to be detected
if (timer % 100 == 0)
{
select_pin_val = digitalRead(button_pin);
if (select_pin_val == HIGH)
{
string_select = ((string_select + 1) % 6);
Serial.print("string: ");
Serial.println(string_select);
}
}

// Depending on which string is selected, the proper variables are set
switch (string_select)
{
case 0:
digitalWrite(led_e4, LOW); // sets the proper LED on, all else off
digitalWrite(led_b3, LOW);
digitalWrite(led_g3, LOW);
digitalWrite(led_d3, LOW);
digitalWrite(led_a2, LOW);
digitalWrite(led_e2, HIGH);
a = 0.045;
b = 0.9099;
threshold = 150;
upper_bound = 77;
lower_bound = 33;
avg_upper = 57;
in_tune = 55; // This is the ?in tune? average of cross counts for the string.
avg_lower = 53;
timer_divide = 2000;
divide_by = 3;
break;
case 1:
digitalWrite(led_e4, LOW); // sets the proper LED on, all else off
digitalWrite(led_b3, LOW);
digitalWrite(led_g3, LOW);
digitalWrite(led_d3, LOW);
digitalWrite(led_a2, HIGH);
digitalWrite(led_e2, LOW);
a = 0.0592;
b = 0.8816;
threshold = 150;
upper_bound = 88;
lower_bound = 44;
avg_upper = 67;
in_tune = 65; // This is the ?in tune? average of cross counts for the string.
avg_lower = 63;
timer_divide = 2000;
divide_by = 3;
break;
case 2:
digitalWrite(led_e4, LOW); // sets the proper LED on, all else off
digitalWrite(led_b3, LOW);
digitalWrite(led_g3, LOW);
digitalWrite(led_d3, HIGH);
digitalWrite(led_a2, LOW);
digitalWrite(led_e2, LOW);
a = 0.0797;
b = 0.8406;
threshold = 150;
upper_bound = 117;
lower_bound = 63;
avg_upper = 97;
in_tune = 95; // This is the ?in tune? average of cross counts for the string.
avg_lower = 93;
timer_divide = 2000;
divide_by = 3;
break;
case 3:
digitalWrite(led_e4, LOW); // sets the proper LED on, all else off
digitalWrite(led_b3, LOW);
digitalWrite(led_g3, HIGH);
digitalWrite(led_d3, LOW);
digitalWrite(led_a2, LOW);
digitalWrite(led_e2, LOW);
a = 0.0730;
b = 0.8541;
threshold = 130;
upper_bound = 50;
lower_bound = 15;
avg_upper = 29;
in_tune = 27; // This is the ?in tune? average of cross counts for the string.
avg_lower = 26;
timer_divide = 500;
divide_by = 4;
break;
case 4:
digitalWrite(led_e4, LOW); // sets the proper LED on, all else off
digitalWrite(led_b3, HIGH);
digitalWrite(led_g3, LOW);
digitalWrite(led_d3, LOW);
digitalWrite(led_a2, LOW);
digitalWrite(led_e2, LOW);
a = 0.1270;
b = 0.7459;
threshold = 140;
upper_bound = 50;
lower_bound = 15;
avg_upper = 35;
in_tune = 34; // This is the ?in tune? average of cross counts for the string.
avg_lower = 33;
timer_divide = 500;
divide_by = 4;
break;
case 5:
digitalWrite(led_e4, HIGH); // sets the proper LED on, all else off
digitalWrite(led_b3, LOW);
digitalWrite(led_g3, LOW);
digitalWrite(led_d3, LOW);
digitalWrite(led_a2, LOW);
digitalWrite(led_e2, LOW);
a = 0.1648;
b = 0.6705;
threshold = 150;
upper_bound = 60;
lower_bound = 20;
avg_upper = 47;
in_tune = 45; // This is the ?in tune? average of cross counts for the string.
avg_lower = 43;
timer_divide = 500;
divide_by = 4;
break;
}

check_crossings();

// After the string input has been idle for a while, we take the average of a number of cross counts that were in bound.
if (idle_timer == 10000)
{
Serial.println(“AVG AVG LOOK HERE AVG AVG”);
average_val = avg_cross / divide_by;
Serial.println(average_val);

// If else statements for tuner lights
if ((average_val < avg_lower) && (average_val > 0))
{
// Turn off all string display lights to conserve power
digitalWrite(led_e4, LOW);
digitalWrite(led_b3, LOW);
digitalWrite(led_g3, LOW);
digitalWrite(led_d3, LOW);
digitalWrite(led_a2, LOW);
digitalWrite(led_e2, LOW);

// Sets the proper tuning LED on, all else off
digitalWrite(led_high, LOW);
digitalWrite(led_ok, LOW);
digitalWrite(led_low, HIGH);

pitch_diff = in_tune - average_val;
Serial.print("Pitch Difference Low: ");
Serial.println(pitch_diff);

// If the tuning is off by a questionably high amount, count it as an error in reading and do not turn the peg.
// Otherwise tune the peg for a period of time. This time depends on how far off the read average is.
if (pitch_diff < 20)
for(long i = 0; i < pitch_diff * 36000; i++)
{
digitalWrite(servoPin, HIGH); // start the pulse
delayMicroseconds(15); // pulse width
digitalWrite(servoPin, LOW); // stop the pulse
}
}

// Don’t turn the peg if the guitar is in tune.
else if ((average_val >= avg_lower && average_val <= avg_upper) || (average_val == 0))
{
// Sets the proper tuning LED on, all else off
digitalWrite(led_high, LOW);
digitalWrite(led_ok, HIGH);
digitalWrite(led_low, LOW);
}

else if (average_val > avg_upper)
{
// Turn off all string display lights to conserve power
digitalWrite(led_e4, LOW);
digitalWrite(led_b3, LOW);
digitalWrite(led_g3, LOW);
digitalWrite(led_d3, LOW);
digitalWrite(led_a2, LOW);
digitalWrite(led_e2, LOW);

// Sets the proper tuning LED on, all else off
digitalWrite(led_high, HIGH);
digitalWrite(led_ok, LOW);
digitalWrite(led_low, LOW);

pitch_diff = average_val - in_tune;
Serial.print("Pitch Difference High: ");
Serial.println(pitch_diff);

// If the tuning is off by a questionably high amount, count it as an error in reading and do not turn the peg.
// Otherwise tune the peg for a period of time. This time depends on how far off the read average is.
if (pitch_diff < 20)
for(long i = 0; i < pitch_diff * 270000; i++)
{
digitalWrite(servoPin, HIGH); // start the pulse
delayMicroseconds(2); // pulse width
digitalWrite(servoPin, LOW); // stop the pulse
}
}

// Reset all variables used for pitch detection
cross_count = 0;
avg_cross = 0;
avg_counter = 0;
}

// We take the average of cross counts after the first value in bound. We dismiss the first value since it is usually inaccurate
// for finding a good average.
if (timer % timer_divide == 0){
if (cross_count > lower_bound && cross_count < upper_bound) {
if (avg_counter >= 1 && avg_counter < (divide_by + 1)) {
avg_cross = avg_cross + cross_count;
Serial.print("Runnin Avg cross sum: ");
Serial.println(avg_cross);
}
avg_counter++;
}
Serial.print("cross_count: ");
Serial.println(cross_count);
cross_count = 0;
}
}
void check_crossings()
{
lastx = x;
lasty = y;
x = analogRead(analogPin); // Read the input pin
y = a * x + a * lastx + b * lasty; // Apply Butterworth filter to eliminate high frequencies

// If the string crosses it’s set threshold, add it to the count. If there are no crossings, the idle timer will begin to run.
if (lasty > threshold && y < threshold)
{
cross_count++;
idle_timer = 0;
}
}

}

void check_crossings()
{
lastx = x;
lasty = y;
x = analogRead(analogPin); // Read the input pin
y = a * x + a * lastx + b * lasty; // Apply Butterworth filter to eliminate high frequencies

// If the string crosses it’s set threshold, add it to the count. If there are no crossings, the idle timer will begin to run.
if (lasty > threshold && y < threshold)
{
cross_count++;
idle_timer = 0;
}
}

the problem area is here at the equation y = a * x + a * lastx + b * lasty.why???

If you post code please use the # button to provide the appropiate code tags [ code] [ /code]

thank you guys for a really2 useful informations.now my compiler works correctly.thanks again!! :stuck_out_tongue_closed_eyes:

my compiler works correctly

I think it always did.

The poll says it all.

There is also no such thing as a double in the arduino language - it simply works as a -floating point- variable.

There is also no such thing as a double in the arduino language - it simply works as a long type variable

There is, but it is EXACTLY the same as a float.

Float… I knew what I meant :smiley: It’s been a long week.

A float week? ;)

A float week?

Well not quite, maybe uint16_t week :P

[Warning: this thread now contains geek humour, which some readers may find offensive. Or not funny] That's just a fancy way of saying it has in fact been a short week. Lucky devil!

[Warning: this thread now contains geek humour, which some readers may find offensive. Or not funny] That's just a fancy way of saying it has in fact been a short week. Lucky devil!

Since when is a uint16_t short?

Since when is a uint16_t short?

Well I actually meant to put uint8_t which still isn’t short for a week :confused:
Shows how tired I am.

Since when is a uint16_t short?

Who ever heard of an unsigned short week?

Who ever heard of an unsigned short week?

Well even the Beatles knew about 8 day weeks so weird weeks aren't out of the question :D