Portable Sensing Field Device - UCF Department of EECS
Portable Sensing Field Device Group 4: Joel Yello Khoa Nguyen Dawson Brown Robert Pribyl Goals Laser-Based Rangefinder IR Contactless Temperature Sensor Combine both functions into one light-weight, handheld device activated by a trigger. Provide simultaneous range and temperature readings via a 16x2 LCD output. Motivation
New to optical systems Group interest in laser technology and infrared technology Combines 2 tools used every day Lightweight Small form-factor Easy to read Low power consumption Time of Flight ranging is a challenge Specifications Ranging from 1-50 meters
<+/- 1 meter accuracy in subsequent measurements Temperature readings from 0-5 meters <+/- 2 degree accuracy in subsequent measurements Device should weigh in between 1.5 and 2.5 pounds for portability. LCD must simultaneously display temperature and range when triggered. Block Diagram Power Each individual part of our device operates in a range between 3.3 and 140 volts. Our high voltage supply needs to supply 140 volts. It supplies
400V at 12V, and through testing we have determined it can run 140V at ~5 volts. Our device must remain portable, limiting our options for selecting a power source. We have chosen a series of linear voltage regulators to obtain the different voltages we need. All regulators operate in a temperature range of 0-125 degrees Celsius. Because of this, we must ensure that the heat dissipated on the regulator doesnt exceed a stable operating environment. The equation to determine power dissipation is as follows: Pdis = (Vin Vout) * Iout Source Options cont. Nickel Cadmium
Low voltage per cell (1.2V) Lower cell density in comparison to Lithium-Ion Dangerous technology, cadmium is hazardous to all life forms. 7+ volt pack will take 6+ batteries and generally weigh in at nearly a pound or more and the area is also 3 times larger than the equivalent lithium ion pack Source Options Nickel Metal Hydride Low cell voltage (1.2V) Cell density between 2 and 3 times that of an equivalent nickel cadmium cell Environmentally safe due to the absence of cadmium Very high self discharge rate (5-10% on first
day, .5-1% per day after) A 7.2 volt pack consists of 6 individual cells, weighing in at 8 ounces and takes up 3 times the area of the equivalent lithium ion pack. Source Options cont. Lithium Ion (chosen battery technology) High voltage per cell (~3.7V) High cell density in comparison to other technology Very slow self discharge rate Volatile technology, can catch fire under bad conditions and upon contact with water Less cells to obtain desired voltage, results in smaller design Source Options cont.
9 volt lithium-ion battery 600mAh ~1.5-2.0 hours of operation 9 volts, in operating range of all parts, 4 volts minimum lost over regulators Built-in overcharge/discharge protection circuit Comes paired with a charger Lightweight, single cell battery 7.2 volt lithium-ion battery pack (chosen battery) 750 mAh ~1.5-2.5 hours of continued operation 7.2 volts, in operating range of all parts and not a lot of wasted voltage
Battery charger available Lightweight, 2 AA cell pack, 1.6 ounces LM7805 The 7805 operates between 7 and 25 volts, proper for our power source. Since our supply is 7.2V, there are no concerns in heat production from the voltage difference The 7805 is used to power the transimpedance amplifier, temperature sensor amplifier, and Arduino development board. LD1117V33 The LD1117V33 operate between 5 and 15 volts, proper for our source Dropping 7.2V to 3.3 volts will produce quite a bit of heat, so its possible that we will add a leading resistor to drop the voltage, or apply a heatsink to
the regulator The LD1117V33 will be used to power the TDC GP21 Ranging - Design Considerations Design Considerations Methods of Ranging considered SONAR (ultrasonic) Cheapest to implement Easy to use Distance limited to less than 10m RADAR Can achieve very far distance readings Does not bounce off all objects
LIDAR (Laser\infrared) Best choice: Line of sight ranging and will reflect at least some light off almost all surfaces. Our design will use the time of flight method APD Module Avalanche Photodiode Must be operated under high voltage (100V+) Very sensitive photo-receiver Advantages include:
Exploits the avalanche multiplication process for added gain Ideal for a rangefinder High speed operation High quantum efficiency Design considerations: Terminal capacitance Sensitive to ambient temperature changes Exhibit measurable dark current APD Selection Main selection aspects included:
Low bias operation Peak spectral sensitivity Low price Max dark current Temperature coefficient Selected mid-range Hamamtsu S2381 Manufactur er Part Numbe r Hamamatsu
Temperature effects on S2381 As the ambient temperature increases, the voltage required to maintain constant gain must increase. We are operating with M at 100. High Voltage DC-DC Converter
Decided to buy pre-made converter instead of building our own due to size goal. Emco Q04 outputs 60-400V Maximum output current of 1.25mA Peak-peak output ripple less than .1% Draws less than 100mA under full load at 12v input voltage. As a cube of only 0.5 inches and a weight of just over 4 grams, the Q04 is ideal for portable applications. Ambient Temperature
Adjust Control pin on HV supply must be adjusted to maintain constant gain. Tmp275 Digital output temperature sensor will be used to detect ambient temperature. Eight addresses Two wire serial interface using I2C Capable of reading temperatures with a resolution of 0.0625C Temperature range of -40 to +125C
As ambient temperature changes, analog output from MCU will change from 0-5V; directly changing the HV output. Transimpedance Amplifier Requirements Must be very low noise Must provide acceptable gain Vo max 5 volts pk-pk High speed response
TI OPA847 BJT amplifier High GBP: 3.9GHz High slew rate 950V/us Very low voltage noise of 0.85nV/Hz Since feedback capacitor is inversely proportional to resistance, an additional gain stage will be needed. Circuit Schematic
Shown highlighted in yellow is a current source and input capacitance representing the APD. Boxed in blue is the gain resistor of 12k and feedback capacitance used to control the frequency response. The red box is the additional op-amp that serves as an extra gain stage to put the output voltage in the range of 1-5V. APD Module Schematic Infrared Optical Filter
Required to block out unwanted wavelengths from entering system. IR band-pass filter from Edmund optics. Diameter of 25mm CWL of 780nm Same as output laser. With a Pass-band of only 10nm; the filter is very precise Laser Optics: PCX Lens Edmund Optics: V-Coated 785nm Maximum throughput at 785nm
Glass substrate, N-BK7 (RoHS compliant) 125mm Focal Length Longer Focal Length = More intense focal point Range Measurement Hardware ACAM TDC-GP21 Time to Digital Converter Measures the time difference between 2 signals Capable of implementing TOF laser ranging due to redundant circuitry and propagation delays. Multiple clock signals capable of measuring 3ps intervals
(3 mm) QFN 32 package SPI communication Fire Pulse Generator Output tied to laser module and START channel Cost effective: $40.00 for a large increase in range ACAM TDC-GP21 ATmega328 & Arduino Uno
Board 13 digital GPIO pins 6 analog input pins Can serve as digital GPIO 16 MHz Crystal Oscillator 5V and 3.3V output perfect for prototyping Price: $35.00 SPI and I2C compatible Arduino Uno Environment C-based programming SPI Library (GP21 Communication) I2C Library (TMP 275 Ambient Temp Sensor) LCD Library (Hitachi HD 44780) Extensive Support Community
Online Tutorials Limitations with SPI communication require new functions to be written Ranging Process Flow = External = ATmega328 = GP21 = LCD Arduino-GP21 Prototyping 4 Wire SPI connection
Declare new Slave Select Line for GP21 3.3V Supply from Arduino to TDC LCD Prototyping 4 Wire interface for data transfer (D2-D5) 2 Wire interface for Enable and R/W configuration (D6-D7) 5V supplied by Arduino to power LCD and backlight Prototyping GP21, Arduino, LCD LCD: Fully Functioning GP21: Re-writing the functions needed to communicate with the registers including:
readReg() writeReg() TOeeprom() FROMeeprom() readResult() fetchStatus() Contactless IR Temperature Sensor IR Temperature Function
Temperature need to be control and monitor engineering application like cooling, heating, drying, and storage. Increase ability portable sensing field device by giving temperature measuring function. Considered methods: * * * * Mechanical Thermo-junctive Thermo-resistive Infrared radiation Infrared radiation
Infrared Radiation Reasons Noncontact measurement Require small energy Long wavelength makes infrared radiation transmitted better through various medium. It could emit to all kinds of bodies. Infrared Detection Detectors Consider types: + Quantum: Expensive + Thermal: Thermocouple Thermopile Bolometer Micro Bolometer
* Thermopile: Digital detector : MLX90614 Analog detector: MLX90247 , ZTP 135SR ZTP-135SR Infrared wavelength: 5 m to 15 mm to 15 m to 15 mm FEATURES
Small-size sensor (TO-46 package) Included ambient temperature (thermistor) sensor for compensation High sensitivity Fast response time Low cost Consists of thermo-elements, flat IR filter Thermistor of temperature compensation in a hermetically-sealed package. Variety of filters available to help maximize performance in specific applications Op-amp Chopper AD8628 Lowest Auto-zero Amplifier Noise Low Offset Voltage: 1 VV Input Offset Drift: 0.02 VV/C Very Low Input Bias Current:
Low Supply Current: 1.0 mA Overload Recovery Time: 10 Vs No External Components Required Rail to Rail Input and Output Swing 5V Single-Supply Operation Op-amp Chopper AD8628 High Gain where the PSRR: 100 dB Close-loop gain: 40 dB Gain 1000 times as applied AD8628 * ZTP- 135SR output: estimated around 3 to 5 mV 1000 X (3 5mV) = 3 to 5 V IR Thermometer Optics Single Fresnel Lens made of HDPE Salvaged from porch-light lens Cost-Effective Vs. Germanium or Silicon
Commonly used in low-cost PIR sensors and IR temperature guns Schematics Future Challenges Frequency stability with of the transimpedance amplifier Interfacing TDC to APD module Quantifying the delay of the laser module startup Properly mounting the lens and filter so that its focal point
is on the APD Possibly using a different LCD for increased user experience Enclosure issues Completion Summary 100% 95% 85% 90% 80% 80% 70% 60% 50% 40%
30% 15% 20% 10% 0% Research Design Parts Acquisition Prototyping 10% Programming
Budget to Date Name TDC-GP21 () nmQFN) Arduino Dev Board: ATMEGA328 QFN32 Breakout Board 780nm Laser Module 16x2 LCD Various Resistors Various Capacitors PCXOptical Lens NT65-524 780nm Optical Filter - NT65-723 Li-ion 7.4V LM7805 +5V Regulator LM7905 -5V
Regulator LD1117 3.3V Regulator TMP275 temperature sensor ZTP-135S - IR SENSOR Fresnel Lens S2381 APD Emco Q04 DC - HV DC OPA847 Op-amp x4 Total Source Transducers Direct Element 14 Cost
$35.00 $30.00 Purchased? yes yes Proto-advantage $13.99 yes Aixiz Spark Fun Anywhere Anywhere Edmund Optics
Vladimir Lenin: Leader of the Bolsheviks and ﬁrst ruler of the Soviet Union (U.S.S.R. - Union of Soviet Socialist Republics). Activity #2 Complete the bottom section titled Czars Resist Change and answer the three questions that follow on the handout:...
Lead by dictator Ruled with violence and fear Extreme nationalism Had a strong military Had total control over government Adolf Hitler-Germany Adolf Hitler Benito Mussolini- Italy Benito Mussolini Hideki Tojo-Japan Tojo Winston Churchill- Great Britain Winston Churchill Joseph Stalin-U.S.S.R. Joseph...
That brings us to Plan Continuation Bias. You may know it as Get-there-itus. Whatever you call it it's real and every pilot must learn how to rationally deal with it. This deadly bias will tempt you to delay resorting to...
dental history. complete exam. Paste a few pertinent radiographs or charting on this slide. ... This is one of the slides you can use to display key aspects of your 2D and 3D workup. You can paste exported screen shots...
Ian Spence and the office to describe where we have got to. Ask question when you need to clarify what we say. Goals for the afternoon. You to describe what you understandings and concerns are. All of us to work...
Ready to download the document? Go ahead and hit continue!