JaneMiller at 01:18, 28 March 2015

2015-03-28T01:18:52Z

JaneMiller: Created page with " == Sharp 4-30 cm Analog Distance Sensor == '''Summary''' This sensor detects reflective objects that are 4-30 cm away. The sensor outputs a voltage from approximately 0-3..."

2015-03-28T00:50:27Z

Created page with " == Sharp 4-30 cm Analog Distance Sensor == '''Summary''' *This sensor detects reflective objects that are 4-30 cm away. *The sensor outputs a voltage from approximately 0-3..."

New page

== Sharp 4-30 cm Analog Distance Sensor ==

'''Summary'''
*This sensor detects reflective objects that are 4-30 cm away.
*The sensor outputs a voltage from approximately 0-3.3 volts which you can read into a microcontroller

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'''Wiring'''
*This sensor has three cables coming out of it: red-power, black-ground and white-signal.
*Wire the power cable to the Arduino's 5V, the ground to the Arduino's ground
**Plug the signal cable into any of the Arduino's analog input pins (A0-A5 for the Arduino UNO) with a small pull-down resistor

'''Programming'''
*Looking at the graph on page 4 [https://www.pololu.com/file/0J713/GP2Y0A41SK0F.pdf '''in the datasheet for the sensor''']

@@ Line 13: / Line 13: @@
 '''Programming'''
-*Looking at the graph on page 4 [https://www.pololu.com/file/0J713/GP2Y0A41SK0F.pdf '''in the datasheet for the sensor''']
+*Looking at the graph on page 4 [https://www.pololu.com/file/0J713/GP2Y0A41SK0F.pdf '''in the datasheet for the sensor'''], it looks like the range of 4-30 cm corresponds to a range of 2.5-0.4 volts.
+*We can use the Arduino's analogRead() function to read in this signal. By using the analogRead function, our result will be a number in the range 0-1023, which corresponds to 0-5 volts.
+*To calibrate and find values for our sensor, we can stream the output values of our sensor using a program similar to [http://arduino.cc/en/Tutorial/AnalogReadSerial '''this example'''] from the Arduino website:
+<pre>
+/*
+  AnalogReadSerial
+  Reads an analog input on pin 0, prints the result to the serial monitor.
+  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.
+ This example code is in the public domain.
+ */
+// the setup routine runs once when you press reset:
+void setup() {
+  // initialize serial communication at 9600 bits per second:
+  Serial.begin(9600);
+}
+// the loop routine runs over and over again forever:
+void loop() {
+  // read the input on analog pin 0:
+  int sensorValue = analogRead(A0);
+  // print out the value you read:
+  Serial.println(sensorValue);
+  delay(1);        // delay in between reads for stability
+}
+</pre>
+*To trigger some event when an object is further than a certain distance away, instead of using Serial.println on our sensorValue variable, we could compare it to some min_value variable using an if statement:
+<pre>
+int min_val=30;
+void setup(){
+}
+void loop() {
+ //read sensor value
+ int sensorValue= analogRead(A0)
+ //convert this value to a distance, consider using the "map" function
+ if (sensorValue > min_val)
+ {
+  // activate your event using a digitalWrite or some other function
+ }
+ delay(1); //delay between readings
+}
+</pre>
+*Try using this distance sensor with a few RGB LEDs to "show" how far away an object is with the intensity of the color of the LEDs!
+**Try using the RGB LEDs with this sensor like a red/yellow/green stoplight

Analog Distance Sensor - Revision history

JaneMiller at 01:18, 28 March 2015

JaneMiller: Created page with " == Sharp 4-30 cm Analog Distance Sensor == '''Summary''' *This sensor detects reflective objects that are 4-30 cm away. *The sensor outputs a voltage from approximately 0-3..."

JaneMiller: Created page with " == Sharp 4-30 cm Analog Distance Sensor == '''Summary''' This sensor detects reflective objects that are 4-30 cm away. The sensor outputs a voltage from approximately 0-3..."