4. EvaluationEvaluating the effectiveness of the animal deterrent design relies on testing the major componentsof the product. The design’s main functions are to output visual and audio warnings when thedevice is triggered by animal movement. Once the device is triggered the microprocessor willstore the date and time creating a historical data log. The basic functionality of the project designcan be tested traditionally to determine whether the component is meeting operational designconstraints. Other aspects of the design will need to be tested and evaluated in actual use todetermine effective deterring patterns and make changes if needed.4.1 Evaluation Testing ResourcesSpectrum Analyzer with High Frequency Microphone Input: Used to test the ultrasonicand sonic audio intensity (decibel level) output of the speaker. It is also used to measureintensity and pitch levels at various distances from the device in order to map the areacovered by the speaker outputs.Oscilloscope: Used for analyzing audio outputs from the Pic18 microcontroller and FlashDigital-to-Analog Controller (DAC). It is also used in testing and circuit debugging.Function Generator: Needed to provide test waveforms for the audio circuit in comparisonwith the waveform generation from the microcontroller and DAC. DC Power Supply: Provides multiple direct-current (DC) voltage levels and grounds that areneeded for each of the individual components of the circuit design. The DC powersupply also allows the user to vary the output. This is important because somecomponents vary in function when supplied with different voltage levels.Digital Multi-meter: Measures general voltage, current, and resistance in individualcomponents of the circuit design.Resistance Box: Provides the capability of varying resistance values. The audio output isevaluated with varying loads attached to the amplifier to determine an optimized loadingfor the RC load attached to the amplifier.PSPICE: Computer simulations are needed to estimate gain and simulate smaller controllingcircuits in the circuit design before they are actually implemented on a prototype board.4.2 Hardware and Software SpecificationsHardware test specifications clarify the steps that will be taken to determine if each component ofthe hardware design is working properly. Each of the major components will be discussedindividually with the smaller circuit connection details being discussed collectively. The mainhardware components are the motion sensor, the rectifier circuit, the audio circuit, the speakeroutput, and the microcontroller circuit. Other components of the design such as the relay switch,power input, power regulation, and enclosure shielding will also be discussed in detail. Eachportion of the design will emphasize the importance of meeting design constraints and in turndetermine if each component is functional.4.2.1 Motion Triggering InputThe motion triggering input includes the viewing parameters of the motion sensor. This includestesting the sensitivity and viewing angles of the sensor. The sensitivity is tested by using differentsize objects to trigger the input. The viewing angle will use the different size object enteringfrom different horizontal and vertical viewing angles. The result of these experiments willdevelop all of the testing criteria for the input of the motion sensor.4.2.1.1 Motion SensorThe motion sensor relies on 120 VAC. When the motion sensor is triggered the control wireoutputs 120 VAC for four seconds. This was measured with a multi-meter to determine correctfunctionality before feeding it to the rectifier circuit.4.2.1.2 Rectifier CircuitThe rectifier circuit is used to convert the 120 VAC output from the motion sensor control wireinto 5 VDC. The rectifier circuit is a full-wave rectifier with the output across the bridge resistorresults into the 5 VDC required. The waveform of the rectifier circuit is rippling slightly. Thisripple is smoothed out by the use of a capacitor. An oscilloscope is used to determine if the rippledoes not go below 3 VDC. The microcontroller uses this input to determine of the motion sensoris activated. If the input to the microcontroller were to go below the 3 VDC, the microcontrollerwould stop transmitting an output. Therefore, the output from the rectifier circuit must remainabove the 3 VDC.Figure 1: Rectifier Circuit: Input and Output Voltage Versus Time4.2.2 Audible Warning OutputThe audio warning output involves testing the output parameters of the design. The operation ofthe amplifier circuit and the output of the piezo-electric speakers are tested to determine theaudible warning output.4.2.2.1 Amplifier CircuitThe amplifier circuit was tested for its frequency response and gain. The function generator wasused as the input to the amplifier circuit. Two channels of the o-scope were used to verify theinput signal and measure the amplified output signal. The gain of amplifier was 18 and thefrequency response was stable throughout the desired 1k-30kHz operating range. Figure 2: Audio Amplifier: Gain Versus Frequency4.2.3 Microcontroller CircuitThe microcontroller circuit includes a PIC18242 microcontroller, Flash DAC, and two serialEEPROM memory modules. This circuit is essentially the “brains” of the entire circuit designand will control the function of the entire device. The Pic18 is the primary device in the circuit,and it must be tested thoroughly to ensure proper communication with the other circuitcomponents.4.2.3.1 Serial EEPROM MemoryThe two EEPROM (electrically erasable programmable read-only memory) modules in the circuitare connected to the Pic18 through an I²C interface. This is a two-wire serial interface that sendsencoded packets of information to all devices attached to the I²C interface. Each I²C compatibledevice in the circuit is hard-wired with three specific logic values. The two EEPROM modulesare programmed as 110 and 011 to establish themselves as separate units. The main performancetest with these devices is to send, store, and retrieve data to the EEPROMS. This test will be performed by sending a test data sample to each EEPROM unit separately, eachwith its own identity information. When the information is retrieved from the EEPROM, it willbe displayed on a personal computer (PC) to prove that the data is the same data previously sentto
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