1.  HC-SR05 / SRF05 (pulseIn)

• HC-SR05 Ultrasonic Ranging Module - 5 Pin @ Spikenzielabs 

/*
By : Thomas Ouellet Fredericks
Connect the Ultrasonic Sensor's TRIGGER pin to digital pin 7.
Ground the MODE/OUT pin.
*/

#define ULTRASONIC_TRIGGER 7


void setup() {
        Serial.begin(57600);
}


void loop() {

        // TRIGGER PULSE
        // set as OUTPUT and send a 11 us pulse :
        pinMode(ULTRASONIC_TRIGGER,OUTPUT);
        digitalWrite(ULTRASONIC_TRIGGER, HIGH);
        delayMicroseconds(11);
        digitalWrite(ULTRASONIC_TRIGGER, LOW);

        // LISTEN FOR PULSE
        // Set as input :
        pinMode(ULTRASONIC_TRIGGER,INPUT);
        // Listen for HIGH pulse :
        unsigned long microseconds = pulseIn(ULTRASONIC_TRIGGER, HIGH);

        // SERIAL OUTPUT RESULTS
        // Serial print microseconds :
        Serial.print("microseconds ");
        Serial.println(microseconds);
        // Serial print centimeters :
        Serial.print("cm ");
        Serial.println(microseconds/58);

        // PAUSE
        // Wait at least 50 ms :
        delay(50);

}

2.  SeeedStudio (pulseIn)

Code Arduino:

// Connect the ultrasonic sensor to digital pin 7
#define SUS 7


void setup() {

        Serial.begin(57600);

}


void loop() {

        pinMode(SUS,OUTPUT);
        digitalWrite(SUS, HIGH);
        delayMicroseconds(10);
        digitalWrite(SUS, LOW);

        // Wait for HIGH
        pinMode(SUS,INPUT);
        unsigned long duration = pulseIn(SUS, HIGH);

        Serial.println(microsecondsToCentimeters(duration));
        delay(50);

}

long microsecondsToCentimeters(long microseconds)
{

        return microseconds / 58;
}

3.  Maxsonar EZ1 (analogique)

3.1  Fiche technique

• maxsonar_ez1_fiche_technique.pdf

3.2  Un seul Maxsonar EZ1

• Branchez la broche analogique à une entrée analogique de l'Arduino.
• Branchez la broche 5V au 5V de l'Arduino.
• Branchez la broche GND au GND de l'Arduino.
• Branchez la broche RX seulement si vous utilisez plusieurs MaxSonar EZ1.

3.3  Plusieurs Maxsonar EZ1

«To have the circuit continuously loop so the chain is always giving an analog voltage output, connect pin 5 of the last sensor in the sequence to pin 4 of the first sensor in sequence with a 1K resistor in sequence between the pin 5 output and pin 4 input. [...] With these sensor chaining methods, once pin 4 is pulled high for 20uS on the first sensor, all sensors will chain sequencially. After the micro controller brings pin 4 high, the micro controller will have to return it’s pin to a high impedance state so that after the sequence is complete the TX signal output from the last sensor will trigger the RX of the first sensor.»

Plus d'informations : Multiple_MaxSonar_Sensors.pdf