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I'm new to Arduino and I'm doing an ultrasonic project where I test for the speed of sound. My code is below and for some reason, this is what the serial port returns:
This is the measured speed of sound: inf m/s
This is the measured speed of sound: 0m/s
This is the measured speed of sound: 0m/s
etc...
Here's my code. Any help's massively appreciated:)
int trig = 13;
int echo = 11;
float target_distance = 0.3;
float recieved;
float speed_of_sound;
void setup() {
Serial.begin(9600);
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);
}
void loop() {
digitalWrite(trig, LOW);
delayMicroseconds(2000);
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);
recieved=pulseIn(echo, HIGH);
recieved = recieved*1000000.0;
speed_of_sound = (2*target_distance)/recieved;
Serial.print("This is the measured speed of sound: ");
Serial.print (speed_of_sound);
Serial.println("m/s");
delay(3000);
}
arduino-uno
edited 7 hours ago
Ghanima
401417
asked 8 hours ago
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add a comment |
I'm new to Arduino and I'm doing an ultrasonic project where I test for the speed of sound. My code is below and for some reason, this is what the serial port returns:
This is the measured speed of sound: inf m/s
This is the measured speed of sound: 0m/s
This is the measured speed of sound: 0m/s
etc...
Here's my code. Any help's massively appreciated:)
int trig = 13;
int echo = 11;
float target_distance = 0.3;
float recieved;
float speed_of_sound;
void setup() {
Serial.begin(9600);
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);
}
void loop() {
digitalWrite(trig, LOW);
delayMicroseconds(2000);
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);
recieved=pulseIn(echo, HIGH);
recieved = recieved*1000000.0;
speed_of_sound = (2*target_distance)/recieved;
Serial.print("This is the measured speed of sound: ");
Serial.print (speed_of_sound);
Serial.println("m/s");
delay(3000);
}
arduino-uno
edited 7 hours ago
Ghanima
401417
asked 8 hours ago
ThisUsernameHasBeenTakenThisUsernameHasBeenTaken
252
New contributor
ThisUsernameHasBeenTaken is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
What do you expect the division of 0.6 with 1000000 * some value?
– Vaibhav
8 hours ago
add a comment |
I'm new to Arduino and I'm doing an ultrasonic project where I test for the speed of sound. My code is below and for some reason, this is what the serial port returns:
This is the measured speed of sound: inf m/s
This is the measured speed of sound: 0m/s
This is the measured speed of sound: 0m/s
etc...
Here's my code. Any help's massively appreciated:)
int trig = 13;
int echo = 11;
float target_distance = 0.3;
float recieved;
float speed_of_sound;
void setup() {
Serial.begin(9600);
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);
}
void loop() {
digitalWrite(trig, LOW);
delayMicroseconds(2000);
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);
recieved=pulseIn(echo, HIGH);
recieved = recieved*1000000.0;
speed_of_sound = (2*target_distance)/recieved;
Serial.print("This is the measured speed of sound: ");
Serial.print (speed_of_sound);
Serial.println("m/s");
delay(3000);
}
arduino-uno
edited 7 hours ago
Ghanima
401417
asked 8 hours ago
ThisUsernameHasBeenTakenThisUsernameHasBeenTaken
252
New contributor
ThisUsernameHasBeenTaken is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I'm new to Arduino and I'm doing an ultrasonic project where I test for the speed of sound. My code is below and for some reason, this is what the serial port returns:
This is the measured speed of sound: inf m/s
This is the measured speed of sound: 0m/s
This is the measured speed of sound: 0m/s
etc...
Here's my code. Any help's massively appreciated:)
int trig = 13;
int echo = 11;
float target_distance = 0.3;
float recieved;
float speed_of_sound;
void setup() {
Serial.begin(9600);
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);
}
void loop() {
digitalWrite(trig, LOW);
delayMicroseconds(2000);
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);
recieved=pulseIn(echo, HIGH);
recieved = recieved*1000000.0;
speed_of_sound = (2*target_distance)/recieved;
Serial.print("This is the measured speed of sound: ");
Serial.print (speed_of_sound);
Serial.println("m/s");
delay(3000);
}
arduino-uno
arduino-uno
edited 7 hours ago
Ghanima
401417
asked 8 hours ago
ThisUsernameHasBeenTakenThisUsernameHasBeenTaken
252
New contributor
ThisUsernameHasBeenTaken is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 7 hours ago
Ghanima
401417
asked 8 hours ago
ThisUsernameHasBeenTakenThisUsernameHasBeenTaken
252
New contributor
ThisUsernameHasBeenTaken is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 7 hours ago
Ghanima
401417
edited 7 hours ago
Ghanima
401417
edited 7 hours ago
Ghanima
401417
401417
asked 8 hours ago
ThisUsernameHasBeenTakenThisUsernameHasBeenTaken
252
New contributor
ThisUsernameHasBeenTaken is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 8 hours ago
ThisUsernameHasBeenTakenThisUsernameHasBeenTaken
252
asked 8 hours ago
ThisUsernameHasBeenTakenThisUsernameHasBeenTaken
252
252
New contributor
ThisUsernameHasBeenTaken is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
ThisUsernameHasBeenTaken is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
What do you expect the division of 0.6 with 1000000 * some value?
– Vaibhav
8 hours ago
add a comment |
What do you expect the division of 0.6 with 1000000 * some value?
– Vaibhav
8 hours ago
What do you expect the division of 0.6 with 1000000 * some value?
– Vaibhav
8 hours ago
What do you expect the division of 0.6 with 1000000 * some value?
– Vaibhav
8 hours ago
add a comment |
1 Answer
1
active
oldest
votes
Assuming the speed of sound is of the order of 330 m/s, you expect
the round-trip to the target and back to last about 1.8 ms. Then
recieved = pulseIn(echo, HIGH);
should give a value close to 1,800, and
recieved = recieved * 1000000.0;
should make received something like 1.8 × 109.
Then
speed_of_sound = (2*target_distance)/recieved;
gives a speed of sound of 3.3 × 10−10. It is the
correct value if you want that speed in meters per picosecond, but this
is inconsistent with your program printing “m/s” after the value.
The Arduino's Serial.print() is quite dumb with floating point
numbers. It defaults to printing two digits after the decimal point,
irrespective of the order of magnitude of the number. Thus, anything
smaller than 0.005 gets printed as “0”.
I don't quite understand why you got ∞ on the first loop. Looks like
pulseIn() missed the pulse and returned zero, in which case the speed
is computed as 0.6 ÷ 0 = ∞.
The solution is to compute received as
recieved = pulseIn(echo, HIGH) * 1e-6;
This can be remembered by thinking that a quantity (round-trip time) is
a numeric value (pulseIn(echo, HIGH)) multiplied by a unit (1e-6,
which stands for “microseconds”).
answered 6 hours ago
Edgar BonetEdgar Bonet
25.5k22546
nice, thorough answer. (voted)
– Duncan C
5 hours ago
Ah, a maths error... thats embarrasing. I assumed it was my code. Thanks for taking the time to help though! I just changed the faulty line to: recieved = recieved/1000000 and apart from the first line being "inf", it works well now.
– ThisUsernameHasBeenTaken
5 hours ago
add a comment |
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votes
Assuming the speed of sound is of the order of 330 m/s, you expect
the round-trip to the target and back to last about 1.8 ms. Then
recieved = pulseIn(echo, HIGH);
should give a value close to 1,800, and
recieved = recieved * 1000000.0;
should make received something like 1.8 × 109.
Then
speed_of_sound = (2*target_distance)/recieved;
gives a speed of sound of 3.3 × 10−10. It is the
correct value if you want that speed in meters per picosecond, but this
is inconsistent with your program printing “m/s” after the value.
The Arduino's Serial.print() is quite dumb with floating point
numbers. It defaults to printing two digits after the decimal point,
irrespective of the order of magnitude of the number. Thus, anything
smaller than 0.005 gets printed as “0”.
I don't quite understand why you got ∞ on the first loop. Looks like
pulseIn() missed the pulse and returned zero, in which case the speed
is computed as 0.6 ÷ 0 = ∞.
The solution is to compute received as
recieved = pulseIn(echo, HIGH) * 1e-6;
This can be remembered by thinking that a quantity (round-trip time) is
a numeric value (pulseIn(echo, HIGH)) multiplied by a unit (1e-6,
which stands for “microseconds”).
answered 6 hours ago
Edgar BonetEdgar Bonet
25.5k22546
nice, thorough answer. (voted)
– Duncan C
5 hours ago
Ah, a maths error... thats embarrasing. I assumed it was my code. Thanks for taking the time to help though! I just changed the faulty line to: recieved = recieved/1000000 and apart from the first line being "inf", it works well now.
– ThisUsernameHasBeenTaken
5 hours ago
add a comment |
Assuming the speed of sound is of the order of 330 m/s, you expect
the round-trip to the target and back to last about 1.8 ms. Then
recieved = pulseIn(echo, HIGH);
should give a value close to 1,800, and
recieved = recieved * 1000000.0;
should make received something like 1.8 × 109.
Then
speed_of_sound = (2*target_distance)/recieved;
gives a speed of sound of 3.3 × 10−10. It is the
correct value if you want that speed in meters per picosecond, but this
is inconsistent with your program printing “m/s” after the value.
The Arduino's Serial.print() is quite dumb with floating point
numbers. It defaults to printing two digits after the decimal point,
irrespective of the order of magnitude of the number. Thus, anything
smaller than 0.005 gets printed as “0”.
I don't quite understand why you got ∞ on the first loop. Looks like
pulseIn() missed the pulse and returned zero, in which case the speed
is computed as 0.6 ÷ 0 = ∞.
The solution is to compute received as
recieved = pulseIn(echo, HIGH) * 1e-6;
This can be remembered by thinking that a quantity (round-trip time) is
a numeric value (pulseIn(echo, HIGH)) multiplied by a unit (1e-6,
which stands for “microseconds”).
answered 6 hours ago
Edgar BonetEdgar Bonet
25.5k22546
nice, thorough answer. (voted)
– Duncan C
5 hours ago
Ah, a maths error... thats embarrasing. I assumed it was my code. Thanks for taking the time to help though! I just changed the faulty line to: recieved = recieved/1000000 and apart from the first line being "inf", it works well now.
– ThisUsernameHasBeenTaken
5 hours ago
add a comment |
Assuming the speed of sound is of the order of 330 m/s, you expect
the round-trip to the target and back to last about 1.8 ms. Then
recieved = pulseIn(echo, HIGH);
should give a value close to 1,800, and
recieved = recieved * 1000000.0;
should make received something like 1.8 × 109.
Then
speed_of_sound = (2*target_distance)/recieved;
gives a speed of sound of 3.3 × 10−10. It is the
correct value if you want that speed in meters per picosecond, but this
is inconsistent with your program printing “m/s” after the value.
The Arduino's Serial.print() is quite dumb with floating point
numbers. It defaults to printing two digits after the decimal point,
irrespective of the order of magnitude of the number. Thus, anything
smaller than 0.005 gets printed as “0”.
I don't quite understand why you got ∞ on the first loop. Looks like
pulseIn() missed the pulse and returned zero, in which case the speed
is computed as 0.6 ÷ 0 = ∞.
The solution is to compute received as
recieved = pulseIn(echo, HIGH) * 1e-6;
This can be remembered by thinking that a quantity (round-trip time) is
a numeric value (pulseIn(echo, HIGH)) multiplied by a unit (1e-6,
which stands for “microseconds”).
answered 6 hours ago
Edgar BonetEdgar Bonet
25.5k22546
Assuming the speed of sound is of the order of 330 m/s, you expect
the round-trip to the target and back to last about 1.8 ms. Then
recieved = pulseIn(echo, HIGH);
should give a value close to 1,800, and
recieved = recieved * 1000000.0;
should make received something like 1.8 × 109.
Then
speed_of_sound = (2*target_distance)/recieved;
gives a speed of sound of 3.3 × 10−10. It is the
correct value if you want that speed in meters per picosecond, but this
is inconsistent with your program printing “m/s” after the value.
The Arduino's Serial.print() is quite dumb with floating point
numbers. It defaults to printing two digits after the decimal point,
irrespective of the order of magnitude of the number. Thus, anything
smaller than 0.005 gets printed as “0”.
I don't quite understand why you got ∞ on the first loop. Looks like
pulseIn() missed the pulse and returned zero, in which case the speed
is computed as 0.6 ÷ 0 = ∞.
The solution is to compute received as
recieved = pulseIn(echo, HIGH) * 1e-6;
This can be remembered by thinking that a quantity (round-trip time) is
a numeric value (pulseIn(echo, HIGH)) multiplied by a unit (1e-6,
which stands for “microseconds”).
answered 6 hours ago
Edgar BonetEdgar Bonet
25.5k22546
answered 6 hours ago
Edgar BonetEdgar Bonet
25.5k22546
answered 6 hours ago
Edgar BonetEdgar Bonet
25.5k22546
answered 6 hours ago
Edgar BonetEdgar Bonet
25.5k22546
25.5k22546
nice, thorough answer. (voted)
– Duncan C
5 hours ago
Ah, a maths error... thats embarrasing. I assumed it was my code. Thanks for taking the time to help though! I just changed the faulty line to: recieved = recieved/1000000 and apart from the first line being "inf", it works well now.
– ThisUsernameHasBeenTaken
5 hours ago
add a comment |
nice, thorough answer. (voted)
– Duncan C
5 hours ago
Ah, a maths error... thats embarrasing. I assumed it was my code. Thanks for taking the time to help though! I just changed the faulty line to: recieved = recieved/1000000 and apart from the first line being "inf", it works well now.
– ThisUsernameHasBeenTaken
5 hours ago
nice, thorough answer. (voted)
– Duncan C
5 hours ago
nice, thorough answer. (voted)
– Duncan C
5 hours ago
Ah, a maths error... thats embarrasing. I assumed it was my code. Thanks for taking the time to help though! I just changed the faulty line to: recieved = recieved/1000000 and apart from the first line being "inf", it works well now.
– ThisUsernameHasBeenTaken
5 hours ago
Ah, a maths error... thats embarrasing. I assumed it was my code. Thanks for taking the time to help though! I just changed the faulty line to: recieved = recieved/1000000 and apart from the first line being "inf", it works well now.
– ThisUsernameHasBeenTaken
5 hours ago
add a comment |
ThisUsernameHasBeenTaken is a new contributor. Be nice, and check out our Code of Conduct.
ThisUsernameHasBeenTaken is a new contributor. Be nice, and check out our Code of Conduct.
ThisUsernameHasBeenTaken is a new contributor. Be nice, and check out our Code of Conduct.
ThisUsernameHasBeenTaken is a new contributor. Be nice, and check out our Code of Conduct.
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What do you expect the division of 0.6 with 1000000 * some value?
– Vaibhav
8 hours ago