/*
/*
Two Maxbotix LV EZ1 sonic sensors wired in parallel
*/
const int sonarSensorPinL = 5; //connected to left sonar pwm pin
const int sonarSensorPinR = 6; //connected to right sonar pwm pin
const int sonarTriggerPinR = 7; //connected to right sonar RX pin
const int sonarTriggerPinL = 8; //connected to left sonar RX pin
long valueL = 0;
long valueR = 0;
int inchesL = 0;
int inchesR = 0;
unsigned int calval = 0;
void setup()
{
Serial.begin(9600);
pinMode(sonarTriggerPinL, OUTPUT);
pinMode(sonarTriggerPinR, OUTPUT);
}
void loop()
{
if (calval < 1) { // this calls the calibrate subroutine only once when the sketch begins
calibrate ();
}
calval = calval + 1;
// Read the value from each sensor pin
digitalWrite(sonarTriggerPinR, HIGH);
valueR = pulseIn(sonarSensorPinR, HIGH);
inchesR = valueR / 147; // 147 microeconds per inch
Serial.print("inches right = ");
Serial.println(inchesR);
delayMicroseconds(20); // can be any langth of delay as long as it's >= 20 microseconds according to data sheet
digitalWrite(sonarTriggerPinR, LOW); //turns off right sonic sensor so that it doesn't read from left sonic pulse
delay(250); // delay for serial monitor
digitalWrite(sonarTriggerPinL, HIGH);
valueL = pulseIn(sonarSensorPinL, HIGH);
inchesL = valueL / 147; // 147 microeconds per inch
Serial.print("inches left = ");
Serial.println(inchesL);
delayMicroseconds(20); // can be any langth of delay as long as it's >= 20 microseconds according to data sheet
digitalWrite(sonarTriggerPinL, LOW); //turns off left sonic sensor so that it doesn't read from right sonic pulse
delay(250); // delay for serial monitor
}
void calibrate ()
{
digitalWrite(sonarTriggerPinR, HIGH);
valueR = pulseIn(sonarSensorPinR, HIGH);
delay(250);
digitalWrite(sonarTriggerPinL, HIGH);
valueL = pulseIn(sonarSensorPinL, HIGH);
delay(250);
}
This is my attempt at making two LV EZ1 sensors give reliable readings without interfering with each other. They are wired in parallel. For the inches to be more readable on the serial monitor, a longer delay would be better, but I wanted some feedback on this setup. In my final design, the serial monitor will be eliminated anyway. Also, I threw in a calibration subroutine. According to the data sheet, http://www.maxbotix.com/documents/MB1010_Datasheet.pdf, the sensor will calibrate once during start up, but I'm not sure that it would calibrate properly since I'm using the RX pins to trigger the sensor. That might be a question for Maxbotix tech support. Anyway, it can't hurt, and it only happens once per 65,536 loops before it rolls back to zero and re-calibrates (see unsigned int). For my purposes that would be just fine.
Unfortunately, the only sonic sensor that I have is tied up with another project, but I have ordered two more. I won't be able to test this code until I receive them. The two sensors will be hooked up facing the same direction with about about 30 to 45 degrees offset. Any input is greatly appreciated. edit: tested and working