Help with Robot

Hello all,

I am familiar with working with arduino, however this is my first time working with making a robot. Long story short, I've a project in which I need to create a simple robot able to run using the Arduino v5.0 sensor shield (this one to be precise: here ) I have a few problems though for one thing when I hook up one Ultrasonic Sensor (HC-SR04) to the specificed place on the shield (according to the schematics URF01+ pins) however, when I try to run the example code from the NewPing library, it always returns 0cm or some gibberish in the serial monitor window and I've tested three of them on the shield. Could someone help me with this? I'm sure it isn't the shield, I've tested four motors on the other pins and they all worked fine.

// ---------------------------------------------------------------------------
// Example NewPing library sketch that does a ping about 20 times per second.
// ---------------------------------------------------------------------------

#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(uS / US_ROUNDTRIP_CM); // Convert ping time to distance in cm and print result (0 = outside set distance range)
  Serial.println("cm");
}

What is the value of US_ROUNDTRIP_CM?

Could it be that uS has been declared as an unsigned int but needs to be bigger than that? Just guessing as a newbie.

Weedpharma

I'm not sure but I think it doesn't have a set a value. Although you did help me come to the solution. I rechecked the code and realized I had forgotten to change the baud value to 115200 and also I had forgotten to change the pin values of trig and echo back to A0 and A1! Haha thank you very much for the assistance though, Weedpharma!

Would anyone happen to know I could possibly run three ultrasonics at the same time using the shield though considering it only has one set of pins for a single ultrasonic?
This is my main problem because I want a robot that could have three of these in front so that it could have full 180 degrees frontal vision.

You should easily be able to run three U/S sensors (you don't need the shield), but beware of running them simultaneously - normally you would fire them sequentially, giving time between each firing to allow distant echoes from the previous pulse time to die.

I'm pretty sure NewPing has examples.

The shield makes it a lot easier for me to connect Micro Servos (Tower Pro 9g). And yes NewPing has the examples I need. Thank you for the tip on running them.