Component Testing And Calibration

Component type (e.g., temp sensor, microcontroller, motor, etc.)

part/model number (vendor/manufacturer name if known)

Component Description:
provide a brief technical description written in your own words (do not take text from the vendor description). describe how this component meets your project requirements if you wish to use them.

Key information from the data sheet:
research and locate the datasheet for each of the sensors. Based on the component specification (datasheet), describe what is the range of values your sensor is expected to measure (e.g., temperature range from 0 to 100 degrees Celsius) and the range of voltage/current the sensor is expected to output. 

Testing:
Describe a how tested and calibrated the sensor. Your description should include a numbered list of steps for testing. List steps to calibrate the sensor. Include data collected in testing and calibration.

References:
URL to the website where you found the datasheet and any sample code.

SECTION I - PING SENSOR [Ultrasonic Module HC-SR04]

A sensor is a device that acquires a physical parameter and converts it into a signal suitable for processing. The signal processing could be optical, electrical or even mechanical. Sensors are embedded in systems and applications with the aim of automating different systems. Temperature sensors are used in chemical processing plants, automobile engines, appliances, and other applications that require temperature monitoring. The light sensors are used in cameras, infrared detectors and ambient lighting applications. The sensors are composed of photoconductors such as photoresistors, photodiodes, or phototransistors. The ultrasonic sensors are used for position measurements. The sound waves emitted are done in the frequency range of 2- 15 Megahertz. It uses the Sonar and Radar technology.  The photogates are used in counting applications where one may require to obtain a period of a given motion. The infrared transmitter and receiver at opposite ends of the sensor and the time at which light is broken is thereafter recorded.

The American National Standards Institute defines the sensor as a device that provides a usable output to a specified measured parameter such as,

SECTION I

PING SENSOR [Ultrasonic Module HC-SR04]

• Component Description

Ultrasonic module HC-SR04 is a range finder component that detects objects within a given range as specified in the datasheet. The interface output formats from the sensor are the pulse width output, analog voltage output, and serial digital output. The object being detected needs to be the object closest to the sensor on its path. The ultrasonic module can be referred to as a sound sensor or a ping sensor. The sensor tends to operate at frequencies higher than those of human hearing. A human being can hear sound frequencies in the range of 20Hz- 40kHz. There are two major sections in the sensor, the trigger and the echo. The trigger sends out a sound wave at a particular frequency. The sensor keeps track of the time between transmission of the sound wave and the sound wave echo. The distance is, therefore, obtained as

These sensors detect sounds using a cone of detection and the cone angle tends to vary with the distance. The ability to detect an object on the path depends on the object orientation to the sensor. Any object that does not fall within the range of the sensor cone of detection is not spotted at all. The effectual angle of the cone of detection is usually at less than 15⁰.  The component can be used to detect objects in a specified range as desired in the project.

SECTION II - TEMPERATURE SENSOR [MCP9700 or MC9701]

• Key Information from the data sheet
  
  

Wire connectivity and product features

Power Supply	+5V DC
Quiescent Current	< 2mA
Working Current	15mA
Effectual Angle	<150
Ranging Distance	2-400 cm
Resolution	0.3 cm
Measuring Angle	300
Trigger Input Pulse Width	10μS
Dimensions	45mm x 20 mm x 15mm
Weight	~ 10g

It works by transmitting an ultrasonic burst and providing an output pulse that corresponds to the time required for the burst echo to return to the sensor. The distance to the target can easily be calculated by measuring the echo pulse. The PING sensor emits a short ultrasonic burst and waits for an echo from the echo point. The ultrasonic burst travels through the air at about 1130 feet per second, hits an object and then bounces back to the sensor. The PING sensor provides an output pulse to the host that will terminate when the echo is detected, so that the width of the pulse corresponds to the distance of the target.

• Testing

The tests were carried out in Proteus 8 Professional using the HC-SR04 and the Arduino Uno and a virtual terminal to display the serial output.

//defining the pins on the Arduino board

 const int trigPin=7;

 const int echoPin=6;

 //to define the distance variables and time variables

 long duration;int distance;

void setup() {// setting pinmodes for the constant pinspinMode(trigPin,OUTPUT);pinMode(echoPin,INPUT);

//start the serial communication

Serial.begin(9600);}void loop() { //inserting the system code here: digitalWrite(trigPin,LOW); delayMicroseconds(2);  //to set the trigger Pin ON for some time

  digitalWrite(trigPin, HIGH);

  delayMicroseconds(10);

  digitalWrite(trigPin, LOW);

  //Reading input from the test pin using the EchoPin

  duration=pulseIn(echoPin,HIGH);

  distance=duration*0.034/2;

  //Printing out the distance on serial monitor (Virtual Monitor)

  Serial.print("Distance");  Serial.print(distance);}

TEMPERATURE SENSOR [MCP9700 or MC9701]

• Component design

The temperature sensor MCP9700 series is designed by the Microchip company. It is a low power linear active thermistor Integrated Circuit. It belongs to the family of analog temperature sensors that convert the temperature in the surrounding to an analog voltage. The sensor is mainly used in home appliances to detect overheating and trigger a fan or collection of heat by the heat sinks. The sensor is also used in office equipment, battery systems and portable equipment, hard disk drives and other PC peripherals and the general-purpose temperature monitoring. The IC uses an internal diode to compute the temperature in the surrounding. The diode electrical characteristics have a temperature coefficient that provides temperature in a given range.

All the temperature and power ratings of the sensor are provided in the data sheet attached to this report. There are different types of temperature sensors. They are thermocouples, resistance temperature detectors, thermistors, infrared sensors, and semiconductors. Some of the common temperature sensor vendors are Watlow, Texas Instrument, National Semiconductor, Maxim, Omega, and Pyrotek. Some of the factors to consider when making a choice of the temperature sensor are low power consumption, serial interface, small, accurate, wide temperature range, the I²C interface, and temperature alarms.

SECTION III - PIR SENSOR [HC-SR501 Pyroelectric infrared]

The IC sensor error is obtained as,

• Key information from the data sheet

Some of the key features of the MCP9700/01 are:

• 5-pin SC-70 Package
• 3-pin TO-92 Package
• 5-pin SOT-23 Package
• Operating temperature range: -40⁰C to 125⁰C
• The temperature coefficient: 19.5mV/⁰C for the MCP9701
• The temperature coefficient: 10mV/⁰C for the MCP9700
• Low power: 6 micro Amperes (type)

            The IC temperature sensor is designed to drive large capacitive loads. The sensors are in turn immune to the board parasitic capacitance, which allows the sensors to be remotely located and to drive long PCB trace or shielded cables to the ADC.

• Testing

Tests were run on Proteus 8 Professional. The input temperature sensor used was the MCP9701. The sensor was tested over a range of temperatures and the sensor converted the values to a voltage range of 2.3 volts to 5.5 volts on the ideal state. My code calibrates the system sensor to read values in a range of 0 to 5 volts.

When simulation is run,

The test code used was:/*

//Setting the input point of the Arduino Uno

    int tempPin=A0;     //analog input from MCP9701

    int tempValue=0;

    float tempVoltOut;void setup() {  Serial.begin(9600); //declare the temp Pin as input pi pinMode(tempPin,INPUT);}void loop () {

  tempValue=analogRead(tempPin);

  tempVoltOut=tempValue*5/1024.0;

  //send the output to the serial

  Serial.print("Voltage: ");

  Serial.println(tempVoltOut);

  delay(500);}

The temperature input is interpreted as a voltage equivalent and analyzed from there to use in the cascading circuit as input. The sensor is calibrated for testing to be suitable for the system.

PIR SENSOR [HC-SR501 Pyroelectric infrared]

• Component design and makeup

The PIR sensor is used in the motion detection in a set apart environment. A PIR sensor is also known as a motion sensor. It is used in many security projects in the detection of motion. One key application is in the banking system especially in the vault section. In many institutions, to conserve the electricity, motion sensors are used to turn the lights on only where there is movement. This is implemented in hallways. The operation is a bit similar to that of the ultrasound detector only this sensor detects motion. The IR detector only looks for infrared that is flashing on and off for about 38,500 times per second.

The sensor is an Infrared Technology patented by Germany imported LHI778 probe design. The sensor has an automatic control module, its highly sensitive, highly reliable, ultra-low voltage operating mode. It finds its application in auto-sensing electrical equipment especially those that are battery powered automatic controlled products.

• Key information from data sheet

Sensitivity (clockwise)	3-7 m
Output timing (clockwise)	3-300 sec
Vcc	+5v – 20v
Trigger Methods	L- disable repeat trigger, H enable repeat trigger
Sensing range	< 1200, within 7m
Temperature Range	-150C to +700C
Delay time	Adjustable (3-5 min)

It is applied in the automatic sensing of light for the floor, bathroom, basement, porch, warehouse, garage, ventilator, and alarm.

• Testing

The PIR sensor is interfaced with Arduino Uno in the testing phase.

When there is no motion, the red LED does not light and the Buzzer is off.

When there is motion, the red LED lights and the buzzer goes off or turns ON.

The test code used is,

#define led 7

#define buzzer 8

#define pirSensor 9

void setup() {Serial.begin(9600);pinMode(pirSensor, INPUT);pinMode(led,OUTPUT);

pinMode(buzzer,OUTPUT)}void loop() {int x= digitalRead(pirSensor);

 if(x==LOW)

{digitalWrite(led,LOW);digitalWrite(buzzer,LOW);Serial.println(x); } else

{digitalWrite(led,HIGH);digitalWrite(buzzer,HIGH); Serial.println(x); }}

TCRT5000 Infrared IR – Infrared Reflective Optical Sensor iRLed & iRNPN [tcrt5000 pair]

• Component design and make up

The TCRT5000, TCRT5000L is the reflective optical sensor with transistor output. This model belongs to a family of reflective sensors which have an infrared emitter and a phototransistor. The two components are enclosed in a leaded package. The leaded package is used to block any visible light from reaching the components. The sensor is released in lead-free soldering and it complies with the set international standards. The sensor is used as a position sensor for the shaft encoders. It is used to detect reflective material such as magnetic tapes in ATMS, and it limits switch for mechanical motions in VCR.

The sensor differs from the ultrasonic sensor and the PIR sensor in that it detects color and distance. This explains why there is so much caution taken in regards to the sealing of the package with lead to block any visible light form reaching the emitter. Some common applications are the line-following robots, auto-data logging on utility meters as the module can sense if a surface is white or black. It uses an active onboard potentiometer as the test input to adjust the sensitivity.

The device is designed by the Vishay Industries Electronics. The device is important in the project in the detection of light changes and color to tell the distance from an obstacle. Some of the few caveats the design of the system faces are

• Real time communication of measurements
• Detection of obstacles based on light is tedious
• It is implemented only in the highly sensitive applications.

• Key information from the data sheet

The sensor has many key features where,

Package type	Leaded
Detector type	Phototransistor
Dimensions	10.2 x 5.8 x 7
Peak operating distance	2.5 mm
Operating range	>20%
Relative collector current	0.2 mm to 15 mm
Emitter Wavelength	950 nm

• Testing

Using Proteus 8 professional, the system tests were obtained as,

The test code used,

int a,b,c;void setup(){Serial.begin(9600);pinMode(6,OUTPUT);}

void loop() {digitalWrite(6,HIGH);    // Turning ON LED

 delayMicroseconds(500);  //wait

 a=analogRead(A3);//take reading from photodiode(pin A3) :noise+signal

 digitalWrite(6,LOW);//turn Off LED

 delayMicroseconds(500);  //wait

 b=analogRead(A3); // again take reading from photodiode :noise

c=a-b;  //taking differnce:[ (noise+signal)-(noise)] just signal

//Serial.print(a); //noise+signal

//Serial.print("t");

//Serial.print(b); //noise

//Serial.print("t");

Serial.println(c);// denoised signal}

When the tests are run or simulating the system we obtained,

The detector has built in optical filters that allow very little light except the 980nm infrared. It has an electronic filter that only allows signals around 38.5 kHz to pass through. This prevents IR interference form common sources such as sunlight and indoor lighting.