Analog Interfacing to Embedded Microprocessors Real World Design Analog Interfacing to Embedded Microprocessors Real World Design Stuart Ball Boston Oxford Auckland Johannesburg Melbourne New Delhi Newnes is an imprint of Butterworth–Heinemann. Copyright © 2001 by Butterworth–Heinemann A member of the Reed Elsevier group All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Recognizing the importance of preserving what has been written, Butterworth–Heinemann prints its books on acid-free paper whenever possible. Library of Congress Cataloging-in-Publication Data Ball, Stuart R., 1956– Analog interfacing to embedded microprocessors : real world design / Stuart Ball. p. cm. ISBN 0-7506-7339-7 (pbk. : alk. paper) 1. Embedded computer
Solution: 1. Thershold. 2. Sensitivity. 3. Full Range. 4. Linearity. 5. Accuracy. 6. Precision. 7. Stability. 8. Hysteresis. 9. Noise. Question 2 Given the circuit below (using a SYH-2R humidity sensor) determine the output voltage for a relative humidity of 70 % at 30 °C if RT = 50 kΩ and VDD= 2.5 V. Solution: Check specification for Humidity Sensor of SYH-2R.pdf at: http://www.rhopointcomponents.com/images/SYH-2R.pdf 2 Week 04 Homework - Solutions Check Thermistor - Wikipedia.pdf at http://en.wikipedia.org/wiki/Thermistor Calculate the Humidity Sensor resistance at 30°C T = 273.15°C +30°C = 303.15°C T0 = 273.15°C +25°C = 298.15°C R60% 30°C =25.5858 kΩ - Matlab code: 33*exp(4600*(1/303.15-1/298.15)) = 25.5858 Calculate the Humidity Sensor resistance at relative humidity 70% See the above graphic for the standard resistance: Exercises - Solutions 3
output voltage for a relative humidity of 70 % at 30 °C if R T = 50 kΩ and VDD= 2.5 V. R70 30 c =R H =9,2 kV RH 9,2 k V O= ∙ V DD= ∙ 2,5 = 0,388 V (R T + R H ) ( 50 k +9,2 k ) Hint: Check specification for Humidity Sensor of SYH-2R.pdf at http://www.rhopointcomponents.com/images/SYH-2R.pdf 2 Week 04 Homework Question 3 Given the following bridge circuit for a strain gauge, determine the value of the strain gauge resistance {RS}. Let: VIN = 5V R3 = 200 Ω R2 = 50 Ω R1 = 100 Ω a) Under no strain (VOUT = 0 V) R2 ∙ R3 RS= =100 Ω R1 b) When VOUT = 0,5 V {under strain}. 100 200 0,1= − 150 200+ RS 200 200 0,56= =¿> RS= −200=¿> RS=157 Ω 200+ RS 0,56 RS ≈157 Ω
binary and then using the twos complement method. Show all your calculations 5810=001110102 4210=001010102 Converse to twos complement 4210=001010102=110101012+1=110101102 Then 58+(42) 001110102 +110101102 = 000100002 =1610 Question 3 Given the following bridge circuit for a strain gauge, determine the value of the strain gauge resistance {RS}. Let: VIN = 5V R3 = 100 Ω R2 = 50 Ω R1 = 100 Ω 2 Midterm Exam - Solutions a) Under no strain (VOUT = 0 V) b) When VOUT = 0,5 V {under strain}. Solution: a) Under no strain: R1 R3 R1R4 R2 R3 VOUT IN V VIN 1 R R 2 R3 R4 1 ( R R2 )( R3 R4
Cat. No. W317-E1-11 SYSMAC CPM1A Programmable Controllers OPERATION MANUAL CPM1A Programmable Controllers Operation Manual Revised October 2007 iv Notice: OMRON products are manufactured for use according to proper procedures by a qualified operator and only for the purposes described in this manual. The following conventions are used to indicate and classify precautions in this manual. Always heed the information provided with them. Failure to heed precautions can result in injury to people or dam- age to property. ! DANGER Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury. Additionally, there may be severe property damage. ! WARNING Indicates a potentially hazardous situation which, if not avoided, could result in death or serious inju
For this to occur, the Q point is located at cutoff on both the dc and ac load lines. Transistors are, because transistorized base bias is usually designed to operate in switching circuits by having either low output voltage or high output voltage.5)on circuits.6)Inverters output voltage is in the opposite polarity to the input voltage.Multiplexer is a multiple switch that steers one of the input signals to the output.Comparator:perfect solution for comparing one voltage with another to see which is larger.Latch:because the collector of T1 drives the base of T2 and vice versa,it is a positive feedback.Achange in current at any point of the loop is amplified and returned to the starting point with the same phase. 7)Advantages of swithces:Extremely low power consumption and lower heat production.Physically small.They can provide large load currents at low voltages although they produce more electrical and audible noise
Homework-04 Solution (100 marks) Read Chapter_4_Time_Based_Measurements.pdf Question 1 (10 marks) When converting an analogue value to a frequency, consider the following diagram describing the system. The frequency changes from 20 MHz to 18 MHz and the system samples at an interval of 2ms. How many counts does the microprocessor detect at, a) 20 MHz? b) 18 MHz? What is the difference in terms of number of counts detected by the microprocessor? Solution: 1 1 a) Converse 20 MHz to time length: T 0.00005ms f 20,000,000 2ms Number of counts in 2ms: N 40,000 0.00005ms 1 1 b) Converse 18 MHz to time length: T 0.000055556ms f 20,000,000
Question 1 Define the following ADC terms: 1. SNR – (Signal to Noise Ratio) SNR is a calculated value that represents the ratio of RMS signal to RMS noise. 2. SINAD - (signal-to-noise-and-distortion ratio) Ratio of the RMS signal amplitude to the mean value of the root-sum-square (RSS) 3. ENOB – (effective number of bits) The effective number-of-bits and relates to SINAD 4. THD - (total harmonic distortion) Ratio of the rms value of the fundamental signal to the mean value of the RSS of its harmonics. 5. SFDR - (spurious free dynamic range) Ratio of the RMS value of the signal to the RMS value of the worst spurious signal. 6. Channels - related to the inputs of the ADC can either be multiplexed or individually selected. 7. Linearity - relates to how a ADC follows a linear function. All ADCs are to a certain extend nonlinearity. 8. Operating temperature - measurement, which i
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