NewPing Library: HC-SR04, SRF05, SRF06, DYP-ME007, Parallax PING))) - v1.7

teckel:

xvjeko: Hello.. i wrote a code that uses this library, and isn't 100% reliable when debugging... I'd be grateful if you comment it.

1) TRIG_PIN_L, TRIG_PIN_R, ECHO_PIN_L and ECHO_PIN_R are never defined. 2) No reason to set the pin modes, NewPing does that for you. 3) You shouldn't set the maximum distance to 2000cm on the "NewPing SONAR" lines. The sensor won't work beyond 500cm and setting it to 2000 could make the time between pings from 33ms to 115ms or just cause problems in general. Just remove the ,2000 and it will default to the sensor's maximum distance, which is 500cm and will allow for 33ms between pings as you have it set. 4) The "constrain" commands will give you problems as out of range results (which are zero) would change to 6. Out of range would typically be beyond 500cm, making it 6cm will probably not give you want you're looking for. Instead, do something like "if (per_l > 0) per_l = constrain(per_l, MIN_DISTANCE, MAX_DISTANCE);" so there can still be a zero result (out of range). 5) The rest of your code then needs to accommodate what to do with out of range results. It doesn't appear that you have considered that. If anything, a zero result should be changed to MAX_DISTANCE + 1, as that's what it means. Without considering a zero result (out of range), your sketch will probably never work.

That should give you a good start to diagnose what's going on. 1, 3, 4 & 5 are real problems that will seriously cause problems for your sketch.

Tim

thank you sir

EDIT: I got everything to work now... I hope it will run flawlessly in the real life... Thanks again

xvjeko: thank you sir

EDIT: I got everything to work now... I hope it will run flawlessly in the real life... Thanks again

Glad to help! Always satisfying when a project starts to come together. Pictures of your final project are always appreciated by the community.

Tim

hello..im using ultrasonic parallax ping))) sensor.can someone share to me coding for velocity (speed) sensor? km/h

matt121187: hello..im using ultrasonic parallax ping))) sensor.can someone share to me coding for velocity (speed) sensor? km/h

What's the size and speed of the object you're trying to track the speed of? Will the object always be heading straight for the sensor or at an angle? If at an angle, is the angle consistent and known?

Tim

teckel:

matt121187: hello..im using ultrasonic parallax ping))) sensor.can someone share to me coding for velocity (speed) sensor? km/h

What's the size and speed of the object you're trying to track the speed of? Will the object always be heading straight for the sensor or at an angle? If at an angle, is the angle consistent and known?

Tim

between two cars..im doing the fyp project..doing the car blind spot detection..this sensor put at the side of the car..then this sensor will measure the distance and speed between my car and side car. actually, for the speed, im not measure the speed of the side car but im measure the different speed between my car and side car..(i think this very simple compare to measure the speed of the side car)

can someone help me... =(

matt121187: can someone help me... =(

First step, make Arduino work with basic code for NewPing.

After you understand how the sketch works you can use variables to calculate speed.

Quoted from this link http://www.unitarium.com/speed-calculator

Assume, V - stands for average speed (velocity), T - stands for traveling time and D - stands for traveled distance.

Average Speed can be calculated by using the formula: V = D/T Traveled distance can be calculated as: D = V*T Traveling time can be calculated using: T = D/V

Using the formulas remember about the units. For example, if the distance is given in meters and the time is given in seconds, calculated average speed is given in meters per second.

cyclegadget:

matt121187: can someone help me... =(

First step, make Arduino work with basic code for NewPing.

After you understand how the sketch works you can use variables to calculate speed.

Quoted from this link http://www.unitarium.com/speed-calculator

Assume, V - stands for average speed (velocity), T - stands for traveling time and D - stands for traveled distance.

Average Speed can be calculated by using the formula: V = D/T Traveled distance can be calculated as: D = V*T Traveling time can be calculated using: T = D/V

Using the formulas remember about the units. For example, if the distance is given in meters and the time is given in seconds, calculated average speed is given in meters per second.

sorry, im new with arduino..what do u mean by " First step, make Arduino work with basic code for NewPing."? from the ping sensor coding, i can get the distance, but how to get the value of times?

Assume, V - stands for average speed (velocity), T - stands for traveling time and D - stands for traveled distance.

Average Speed can be calculated by using the formula: V = D/T Traveled distance can be calculated as: D = V*T Traveling time can be calculated using: T = D/V

You may want to start a thread in the programming questions area for your project. Below, is some help to get you started. You have a sensor that can provide distance information. This is your "D" variable.

You can use millis() or micros() to measure your time between distance checks. This is your "T" variable. FirstMillis() - SecondMillis() = time between distance checks.

V = D/T......."V" velocity, = "D" distance / "T" time.

Before you ask more questions, you need to read this thread so that you will get the best help possible. http://arduino.cc/forum/index.php/topic,97455.0.html

Good luck, your project is easily possible but, you need to put in some time to make it happen.

matt121187: sorry, im new with arduino..what do u mean by " First step, make Arduino work with basic code for NewPing."? from the ping sensor coding, i can get the distance, but how to get the value of times?

You create a time stamp for each ping. Then, looking at multiple ping times, and the comparison to the ping time stamp, you can easily calculate the speed (also if it's getting closer or further away). For example, you have two pings like the following:

Ping 1: Timestamp 50,000uS - Ping time 8,000uS Ping 2: Timestamp 100,000uS - Ping time 7,000uS

So, two pings that are 50ms apart, the first distance is 8000uS (140cm), sencond ping is 7,000uS (123cm). So, in 50ms, it got 17cm closer (140-123). 17cm/50ms = .17/0.05 m/s or 3.4 m/s or 7.6 miles/hour.

Only the previous and current ping timestamp and distance are needed. If you use scheduled polling so you always know exactly how far apart each ping is (for example, exactly 50,000uS) then you don't even need to know the timestamp, just the current and previous ping distance. Just don't use delay(50) to make them 50ms apart, that won't be accurate. You'll need to either use an interrupt timer or polling to keep things accurate. Interrupt timer would be ideal but more complicated unless you used a timer library would would greatly simplify things.

I've written a little sketch for you that uses the NewPing and TimerOne library that outputs the speed via serial and uses the timer interrupt to make the ping timing very accurate. I added lots of comments so you should be able to follow along. Speed values are in meters per second, with positive values coming at you and negative moving away. Anyway, here's the sketch:

#include 
#include 

#define TRIGGER_PIN  12 // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     11 // Arduino pin tied to echo pin on the ultrasonic sensor.

NewPing sonar(TRIGGER_PIN, ECHO_PIN); // NewPing setup of pins.

volatile int previous = 0, current = 0; // Must be volatile because these change inside the interrupt code.
volatile float mps = 0.0;
volatile boolean newping = false;

void setup() {
  delay(1000);                        // Wait a second before we start.
  Timer1.initialize(50000);           // 50000uS = 50ms.
  Timer1.attachInterrupt(pingSensor); // pingSensor to run every 50ms.
  Serial.begin(115200);               // Open serial monitor at 115200 baud to see ping results.
}

void loop() {
  if (newping) { // There a new ping, print speed.
    /* START - This section would be replaced with code that would do something with the result other than just output to serial. */
    if (mps) {   // Non-zero speed, show result.
      Serial.print(mps);
      Serial.println(" m/s");
    } else Serial.println("-"); // Can't determine speed, output "-" instead of speed.
    /* END */
    newping = false; // Set to false till next ping.
  }
}

void pingSensor() {
  previous = current;
  current = sonar.ping_cm(); // Send out a ping and get the results in CM.
  if (previous && current) { // If either are zero, we had a no-ping result or on the first ping.
    mps = (float) (previous - current) * 0.2; // Calculate speed in m/s (positive values are coming at you, negative moving away).
  } else mps = 0; // Can't calculate speed.
  newping = true; // Flag that there's a new ping.
}

Hope this helps!

Tim

Hi,

First of all THANK YOU TIM for this library!!!!!!!!!!!!!!!!!!!! And thank you to all the enthusiasts who have been posting here!

I have been running into a slight problem that I have not been able to fix, despite dowloading the lib again, googling it a million times, etc. I am trying to get readings from a PING))) sensor and from a maxbotic MAX SONAR (which can be PWM, An or BW, I have it as PWM) and arduino throws the same error: 'NewPing' does not name a type

sketch_jan06a:3: error: 'NewPing' does not name a type sketch_jan06a:4: error: 'NewPing' does not name a type sketch_jan06a.cpp: In function 'void loop()': sketch_jan06a:19: error: 'sonar1' was not declared in this scope sketch_jan06a:23: error: 'sonar2' was not declared in this scope

The code I used is the modified sample one provided:

#include 
//barely modified sketch from Tim Eckel's original sketch

NewPing sonar1(11, 12, 200); // Sensor 1: trigger pin, echo pin, maximum distance in cm
NewPing sonar2(9, 10, 200); // Sensor 2: same stuff

#define pingSpeed 100 // Ping frequency (in milliseconds), fastest we should ping is about 35ms per sensor
unsigned long pingTimer1, pingTimer2;

void setup() {
  Serial.begin(9600);
  // Do other stuff here
  pingTimer1 = millis() + pingSpeed; // Sensor 1 fires after 100ms (pingSpeed)
  pingTimer2 = pingTimer1 + (pingSpeed / 2); // Sensor 2 fires 50ms later
}

void loop() {
  if (millis() >= pingTimer1) {
    pingTimer1 += pingSpeed; // Make sensor 1 fire again 100ms later (pingSpeed)
    int in1 = sonar1.ping_in();
  }
  if (millis() >= pingTimer2) {
    pingTimer2 = pingTimer1 + (pingSpeed / 2); // Make sensor 2 fire again 50ms after sensor 1 fires
    int in2 = sonar2.ping_in();
    // Both sensors pinged, process results here
  }
  // Do other stuff here, notice how there's no delays in this sketch, so you have processing cycles to do other things :)
}

Any suggestions would be greatly greatly appreciated..... Thank you!!!!!

teckel:

matt121187: sorry, im new with arduino..what do u mean by " First step, make Arduino work with basic code for NewPing."? from the ping sensor coding, i can get the distance, but how to get the value of times?

You create a time stamp for each ping. Then, looking at multiple ping times, and the comparison to the ping time stamp, you can easily calculate the speed (also if it's getting closer or further away). For example, you have two pings like the following:

Ping 1: Timestamp 50,000uS - Ping time 8,000uS Ping 2: Timestamp 100,000uS - Ping time 7,000uS

So, two pings that are 50ms apart, the first distance is 8000uS (140cm), sencond ping is 7,000uS (123cm). So, in 50ms, it got 17cm closer (140-123). 17cm/50ms = .17/0.05 m/s or 3.4 m/s or 7.6 miles/hour.

Only the previous and current ping timestamp and distance are needed. If you use scheduled polling so you always know exactly how far apart each ping is (for example, exactly 50,000uS) then you don't even need to know the timestamp, just the current and previous ping distance. Just don't use delay(50) to make them 50ms apart, that won't be accurate. You'll need to either use an interrupt timer or polling to keep things accurate. Interrupt timer would be ideal but more complicated unless you used a timer library would would greatly simplify things.

I've written a little sketch for you that uses the NewPing and TimerOne library that outputs the speed via serial and uses the timer interrupt to make the ping timing very accurate. I added lots of comments so you should be able to follow along. Speed values are in meters per second, with positive values coming at you and negative moving away. Anyway, here's the sketch:

#include 
#include 

define TRIGGER_PIN  12 // Arduino pin tied to trigger pin on the ultrasonic sensor.

define ECHO_PIN     11 // Arduino pin tied to echo pin on the ultrasonic sensor.

NewPing sonar(TRIGGER_PIN, ECHO_PIN); // NewPing setup of pins.

volatile int previous = 0, current = 0; // Must be volatile because these change inside the interrupt code. volatile float mps = 0.0; volatile boolean newping = false;

void setup() {  delay(1000);                        // Wait a second before we start.  Timer1.initialize(50000);           // 50000uS = 50ms.  Timer1.attachInterrupt(pingSensor); // pingSensor to run every 50ms.  Serial.begin(115200);               // Open serial monitor at 115200 baud to see ping results. }

void loop() {  if (newping) { // There a new ping, print speed.    /* START - This section would be replaced with code that would do something with the result other than just output to serial. /    if (mps) {   // Non-zero speed, show result.      Serial.print(mps);      Serial.println(" m/s");    } else Serial.println("-"); // Can't determine speed, output "-" instead of speed.    / END */    newping = false; // Set to false till next ping.  } }

void pingSensor() {  previous = current;  current = sonar.ping_cm(); // Send out a ping and get the results in CM.  if (previous && current) { // If either are zero, we had a no-ping result or on the first ping.    mps = (float) (previous - current) * 0.2; // Calculate speed in m/s (positive values are coming at you, negative moving away).  } else mps = 0; // Can't calculate speed.  newping = true; // Flag that there's a new ping. }




Hope this helps!

Tim

tq so much eckel!!its work for me..i using parallax ping ultrasonic sensor and add some more coding..later i post here what ive done..tq so much!!

notsoyyo: Hi,

First of all THANK YOU TIM for this library!!!!!!!!!!!!!!!!!!!! And thank you to all the enthusiasts who have been posting here!

I have been running into a slight problem that I have not been able to fix, despite dowloading the lib again, googling it a million times, etc. I am trying to get readings from a PING))) sensor and from a maxbotic MAX SONAR (which can be PWM, An or BW, I have it as PWM) and arduino throws the same error: 'NewPing' does not name a type

sketch_jan06a:3: error: 'NewPing' does not name a type sketch_jan06a:4: error: 'NewPing' does not name a type sketch_jan06a.cpp: In function 'void loop()': sketch_jan06a:19: error: 'sonar1' was not declared in this scope sketch_jan06a:23: error: 'sonar2' was not declared in this scope

Any suggestions would be greatly greatly appreciated..... Thank you!!!!!

Your exact sketch compiled fine here. But, I can get it to fail and give the above errors by removing the #include line. This means that while you're telling it to load NewPing.h, it can't find it. Most of the time, this means that you didn't install NewPing properly to the correct directory. Libraries are installed inside your "Arduino" library in a subdirectory named "libraries". Inside "libraries" you would create a new directory named "NewPing" with the files in the NewPing zip file in the NewPing directory. See the other directories inside "libraries" for examples of how it should look. The only instructions I have for installing a library with Arduino is:

Put the "NewPing" folder in "libraries\".

If you can't figure out how to correctly install a library, do a web search for how to install an Arduino library, maybe someone else has a better way of describing it.

Tim

alegiaco: Very good job, man!!!! Two questions: - is it possible to use multiple ultrasonic sensors? i.e 4 sensors? - with multiple sensors and a distance between 10 and 20 cm how fast can be the readings? Thanks

For my HC-SR04 app, I use a common trigger signal (to all 8 sensors), then pin-change interrupts to read pulse time. I went outside the libraries to do this. Haven't tried to see how fast I can ping, but they all share the same timeout, currently at .030 sec (30ish Hz max). They don't seem to work for distances longer than about .020 ping time, so I'd think that a max rate of around 40 Hz should be achievable... for full 2+m range.

I don't know how much faster you could go at max 20cm, since subsequent pulses might give false readings from objects around 2-2.5m away.

See http://arduino.cc/forum/index.php/topic,141363.0.html for my test code.

terryking228: I'm writing a library for these: http://goo.gl/FWMjI and I'd love to try some cool mapping ideas with your code...

I'm writing my own too. My test code is posted at http://arduino.cc/forum/index.php/topic,141363.0.html. The big difference for my code is that an array of HC-SR04's all share the same trigger, then read pulse time using pin-change interrupts (on mega).

It is kind of hard for me to generalize pin-change interrupts, so it is somewhat hard-coded. more of an example than a good general-purpose library.

Mr-What:

terryking228: I'm writing a library for these: http://goo.gl/FWMjI and I'd love to try some cool mapping ideas with your code...

I'm writing my own too. My test code is posted at http://arduino.cc/forum/index.php/topic,141363.0.html. The big difference for my code is that an array of HC-SR04's all share the same trigger, then read pulse time using pin-change interrupts (on mega).

It is kind of hard for me to generalize pin-change interrupts, so it is somewhat hard-coded. more of an example than a good general-purpose library.

The problem with pin-change interrupts is that it's not even tested on the Uno, only Mega. It's a little ridged for a general-purpose library. The next release of NewPing should have a pin interrupt-based method. I've expanded my required compatibility to include the Uno, Teensy 2.0, and Teensy 3.0. So, it's a little more challenging at times.

I do have a question for you. How do you deal with pings that don't return? Waiting for the interrupt doesn't work as sometimes there isn't a ping return. I'm building an ultra-low-powered system currently and because I can't rely on getting a ping result, I can't do what I wanted, which is to put the ATmega to sleep while waiting for the pin interrupt. Still got it down to using only 1.27mA, but even lower would be better.

Tim

I have run the pin-change interrupts on UNO... the official pin-change interrupt libraries are tested for UNO, NOT mega.

Either way, you will see that this is kind of hard-coded to my app. It gets very tricky when you want to use specific pins so they share the same interrupt vector. So tricky that I gave up on "proper" programming, and kind of hard-coded pin assignments and interrupts.

My application runs on a constant poll, and will call .timeout() when more than about 20000us have passed. That is not shown... since I just posted my original test script demonstrating use of pin-change interrupts for a sonar array.

Mr-What: I have run the pin-change interrupts on UNO... the official pin-change interrupt libraries are tested for UNO, NOT mega.

Either way, you will see that this is kind of hard-coded to my app. It gets very tricky when you want to use specific pins so they share the same interrupt vector. So tricky that I gave up on "proper" programming, and kind of hard-coded pin assignments and interrupts.

My application runs on a constant poll, and will call .timeout() when more than about 20000us have passed. That is not shown... since I just posted my original test script demonstrating use of pin-change interrupts for a sonar array.

My bad, pinchangeint supports Uno with partial Mega compatibility.

Don't you have to wait at least 29 to 35ms? The sensors work at up to 500cm, which means the pings are still bouncing around for up to 28,500uS.

Also, when I've tried to fire multiple sensors simultaneously, it really only worked well in wide-open spaces. In more closed environments, I'd get cross-sensor echos at times making it unreliable.

With this said, using the Teensy 3.0 is really nice as every pin can be an interrupt. You may want to consider this as it would make things a lot easier. Not to mention the extra horsepower the microcontroller will give you.

Tim

You are right. I need to revisit that. I might need to extend that timeout. I have seen these specific sensors work over 2m (to a flat wall).

Haven't seen cross-talk in my testing yet, but I haven't done anything too stressing. This is for a large robot, so the sensors will be about 20-50 cm apart, more or less radially pointing outward.

For collision avoidance I am hoping that a false positive from a simultaneous ping would not necessarily be a bad thing. If I receive my neighbor's ping from a tilted surface nearby (which I still need to avoid), that is better than not seeing anything. I hope that the first echo sensed causes the pin to go low, and I get the "conservative" estimate of distance to a nearby obstacle.

Teckel, I've received a Due and downloaded NewPing (you asked earlier in the thread). The immediate issues are that it includes "avr/io.h" and "avr/interrupt.h", neither of which seem to have obvious counterparts for the ARM due.

With those headers missing, the following lines become issues:

C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp: In constructor 'NewPing::NewPing(uint8_t, uint8_t, int)':
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:19: error: cannot convert 'volatile RwReg*' to 'volatile uint8_t*' in assignment
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:20: error: cannot convert 'volatile RoReg*' to 'volatile uint8_t*' in assignment
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:22: error: 'portModeRegister' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp: In static member function 'static void NewPing::timer_us(unsigned int, void (*)())':
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:151: error: 'OCR2A' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:152: error: 'TIMSK2' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:152: error: 'OCIE2A' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp: In static member function 'static void NewPing::timer_ms(long unsigned int, void (*)())':
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:167: error: 'OCR2A' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:168: error: 'TIMSK2' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:168: error: 'OCIE2A' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp: In static member function 'static void NewPing::timer_stop()':
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:177: error: 'TIMSK2' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:177: error: 'OCIE2A' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp: In static member function 'static void NewPing::timer_setup()':
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:195: error: 'ASSR' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:195: error: 'AS2' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:196: error: 'TCCR2A' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:196: error: 'WGM21' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:197: error: 'TCCR2B' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:197: error: 'CS22' was not declared in this scope
C:\arduino-1.5.1r2\hardware\arduino\sam\libraries\NewPing\NewPing.cpp:198: error: 'TCNT2' was not declared in this scope