UltraSonic HC-SR04 reading error, displaying different characters

Hello everyone.
Has any of you ever read random characters "(òçöòôg£òôòâôg²«²ððö’ðg’’²ðæô²gðæg“²gò²²ðâà²ð«ôôò£òôgg’", while trying to read data from HC-SR04 Sensor?
I’m pretty sure I’ve made the connections correctly, since I am only trying to use the example sketch from NewPing library.

The wiring:

VCC → 5V
Trig → 12
Echo-> 11
GND → GND

The code I am trying to use:

#include <NewPing.h>
#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.
#define MAX_DISTANCE 200 // Maximum distance we want to ping for (in centimeters). Maximum sensor distance is rated at 400-500cm.

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.

void setup() {
  Serial.begin(115200); // Open serial monitor at 115200 baud to see ping results.
}

void loop() {
  delay(50);                      // Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.
  unsigned int uS = sonar.ping(); // Send ping, get ping time in microseconds (uS).
  Serial.print("Ping: ");
  Serial.print(sonar.convert_cm(uS)); // Convert ping time to distance and print result (0 = outside set distance range, no ping echo)
  Serial.println("cm");
}

And, once again, the reading:

²“’òâ«ô’£²²ðæ²ðà’“’ò²²ðgò’ò²àô²’ôg’’²««ògô’ô’gòâæg’²g²’²«òæggòòàòôgç’ಒòòôg’ò²’æò²²ðgâöôðæ²òô’’«òôð²ðòò²ô²«àô’æg’ðg’g«ô²ð’æ«âಒà²ôôgàògà²ðæô’ô’ððࣲðg£²ôòg’òðgòಒ«òôಒ²’ðð«æô’’²ðæ²ô櫲ôgg’ò²’gࣲgð«òg’«òôgæ²²²«ò²g’ಒòââöðgò²’g£²ô²æ«òôg’«²ðôg’«’ô²ðð’æಒô’’«òâ’gò²ö£²ðægòò²ð櫲ðgòg«ô’²’ðæ²æò²’gàôòô“’²²òg²²ò“ò£òðð’ô’ô𫲲ðgð’òô“’£«òôggæâòæðæ’²ð࣓gò²ôgg’òâ²ðâòâgôgög’ö²ô’’«ô²’[...]and so on[...]

And, once again, the reading:

That looks suspiciously like whatever is getting the data is not doing so at a baud rate of 115200.

  Serial.begin(115200); // Open serial monitor at 115200 baud to see ping results.

make the above number in you code match the number in this window or Vice Versa |500x410 Z

zhomeslice:   Serial.begin(115200); // Open serial monitor at 115200 baud to see ping results.

make the above number in you code match the number in this window or Vice Versa |500x410 Z

Thanks for your reply, it worked on character reading. However, now the sensor only displays: Ping: 0cm, it doesn't get any distance at all. Is it possible that the sensor is bad, and I'm going to need a new sensor? Thanks.

Is it possible that the sensor is bad

Possible, yes. Likely, no.

It is more likely that you do not have the sensor connected correctly. Time to post a diagram showing how it is connected. Pencil and paper is fine.

PaulS: Possible, yes. Likely, no.

It is more likely that you do not have the sensor connected correctly. Time to post a diagram showing how it is connected. Pencil and paper is fine.

Hello, sorry for my late reply. I made a scheme using a website, but cannot find the UltraSonic sensor (the HC-SR04 sensor, they have the Parallax sensor with 3 pins) on their component list, but I can explain how I mounted the sensor on the breadboard.

https://s30.postimg.org/z37k2pgmn/arduino_breadboard.png This is the scheme of Arduino to breadboard connection, and I have mounter the HC-SR04 sensor onto the breadboard according to the code I uploaded on the Arduino.

So it goes Trigger pin to PIN 11 on Arduino, and Echo pin to PIN 12 on Arduino, aswell as 5V to Arduino's 5V, and GND to GND.

So it goes Trigger pin to PIN 11 on Arduino, and Echo pin to PIN 12 on Arduino, aswell as 5V to Arduino's 5V, and GND to GND.

Your code says that the trigger pin is 12, and the echo pin is 11. Which is right?

Yes, you are right, sorry. Trigger pin goes to 12, and Echo goes to 11.

But it still doesn't work...

Dragosh: But it still doesn't work...

I have some alternate code that works with my hcsr-04 ultrasound sensor This doesn't use a class but it does use interrupts For UNO or any Atmega328P Vcc -- 5V Gnd -- Gnd Trig -- Pin 4 Echo -- Pin 3 (interrupt 1)

/*
  pin 3 = Ping Echo *** The arduino has an easy interrupt on pin 3 that will allow us to simplify my code
  pin 4 = Ping trigger
*/
#define TriggerPin  4
// echo pin will be interrupt 1 on pin 3
#define DelayBetweenPings 50 // it works to about 5 milliseconds between pings

volatile  unsigned long PingTime;
volatile  unsigned long edgeTime;
volatile  uint8_t PCintLast;
int PinMask = B1000; // pin 3
float Measurements = 0;

void PintTimer( )
{
  uint8_t pin;
  static unsigned long cTime;
  cTime = micros();         // micros() return a uint32_t
  pin = PIND >> 3 & 1;      // Quickly get the state of  pin 3
  if (pin)edgeTime = cTime; //Pulse went HIGH store the start time
  else { // Pulse Went low calculate the duratoin
    PingTime = cTime - edgeTime; // Calculate the change in time
  }
}
void debug() 
{
  char S[20];
  static unsigned long PingTimer;
  if ((unsigned long)(millis() - PingTimer) >= 100) {
    PingTimer = millis();
    Serial.print(dtostrf(Measurements, 6, 1, S));
    Serial.println();
  }
}

float microsecondsToInches(long microseconds) 
{
  return (float) microseconds / 74 / 2;
}

float microsecondsToCentimeters(long microseconds) 
{
  return (float)microseconds / 29 / 2;
}


void PingTrigger(int Pin)
{
  digitalWrite(Pin, LOW);
  delayMicroseconds(1);
  digitalWrite(Pin, HIGH); // Trigger another pulse
  delayMicroseconds(10);
  digitalWrite(Pin, LOW);
}

void PingIt()
{
  unsigned long PT;
  static unsigned long PingTimer;
  if ((unsigned long)(millis() - PingTimer) >= DelayBetweenPings) {
    PingTimer = millis();
    cli ();         // clear interrupts flag
    PT = PingTime;
    sei ();         // set interrupts flag
    Measurements = (float) (microsecondsToCentimeters(PT));
    //      Measurements = (float) (microsecondsToInches(PT));
    PingTrigger(TriggerPin); // Send another ping
  }
}

void setup()
{
  Serial.begin(115200);
  Serial.println("Ping Test");
  pinMode(3, INPUT);
  pinMode(4, OUTPUT);
  attachInterrupt(1, PintTimer, CHANGE );
}

void loop() 
{
  PingIt(); // Manage ping data
  debug();
}

This is Tested 100% and I can get reading down to 1.9cm (haven't Verified accuracy) This pings every 50 ms but it only shows samples every 100 ms, It can ping as fast as 5ms if you need the resolution. Let me know if this works for you :) Z

void PintTimer( )

PintTimer? For use with pint sensors?

PaulS: void PintTimer( )

PintTimer? For use with pint sensors?

Hasty simplification of an advanced 8 sensor version... Rename as you wish. Gust offering an alternative non blocking way to use the ultrasound sensor :)

zhomeslice:
Hasty simplification of an advanced 8 sensor version… Rename as you wish. Gust offering an alternative non blocking way to use the ultrasound sensor :slight_smile:

Oh, darn. I was hoping you were going to buy me a pint (sensor).