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page 1 S. Derenzo NAME (please print) STUDENT (SID) NUMBER
UNIVERSITY OF CALIFORNIA, BERKELEY
College of Engineering Electrical Engineering and Computer Sciences
EECS 145M: Microcomputer Interfacing Lab
LAB REPORTS:
1 _________________ 2 __________________ 3 ___________________
8 _________________ 9 __________________ 10 ___________________
21 _________________ 22 __________________ 23 ___________________
24a _________________ 24b _________________ Total of top 4 Long Lab Grades Total of top 4 Short Lab Grades Lab Participation Mid-Term # Mid-Term # Final Exam Total Course Grade _______________ (400 max) _______________ (100 max) _______________ (100 max) _______________ (100 max) _______________ (100 max) _______________ (200 max) _______________ (1000 max)
COURSE LETTER
GRADE
Spring 2009 FINAL EXAM (May 15)
Answer the questions on the following pages completely, but as concisely as possible. The exam is to be taken closed book. Use the reverse side of the exam sheets if you need more space. Calculators are OK. Partial credit can only be given if you show your work. FINAL EXAM GRADE : 1 __________ (15 max) 2 __________ (40 max) 3 __________ (45 max) 4 __________ (45 max) 5 __________ (30 max) 6 __________ (25 max) TOTAL __________ (200 max)
PROBLEM 1 (15 points) 1.1 (5 points) State the Fourier convolution theorem 1.2 (10 points) Use the Fourier convolution theorem to show that the Integral Fourier Transform of a periodic waveform contains only discrete frequencies. PROBLEM 2 (total 40 points) 2.1 (15 points) Draw the block diagram for the 12-bit half-flash A/D converter, showing and labeling all principal components and interconnecting lines. ( Note: this converter has two internal flash A/D converters and one internal R-2R D/A converter, and these can be drawn as single boxes).
Problem 3 (45 points) Design a computer-controlled system for testing eight 12 - bit A/D converters. You are provided with the following:
- eight A/D converters (to be tested eight at a time)
- eight 16-bit tri-state drivers
- a microcomputer with the following:
- a 16-bit D/A converter with 1/2 LSB absolute accuracy and 10 μs settling time
- two 16-bit parallel input ports
- two 16-bit parallel output ports You may assume the following:
- The 16-bit parallel output port is in “transparent” mode (no handshaking). New data can be written to the port every 2 μs.
- You have a timer function wait( N ), that can delay program execution for N μs.
- The A/D converter requires a “start conversion” low-to-high edge signal and after conversion provides an “output data available” low-to-high edge. The A/D converter sets “output data available” low and resets all internal functions when “start conversion” goes low.
- You must wait until the A/D has signaled that its data are ready before reading its output. Hint: Think about Laboratory Exercise 9 (A/D converters) and how you would automate the measurement and data analysis procedures. 3.1 (15 points) Draw a block diagram of the major components, including two of the eight A/D converters being tested. Show and label all essential data and control lines.
3.2 (10 points) List the steps your program must do to measure the first transition voltage V(0,1) of the first A/D converter (pseudocode is OK, so long as the logic is clear). 3.3 (10 points) How would you determine the maximum linearity error? 3.4 (10 points) With what accuracy could this system measure the quantities in parts 3.2 and 3.3 in units of 1 LSB of the A/D?
4.2 (5 points) At what frequency f 1 does the Butterworth filter have gain = 0.99? 4.3 (5 points) At what frequency f 2 does the Butterworth filter have gain = 0.001? 4.4 (5 points) What is the minimum sampling frequency that would prevent electromagnetic interference at f 2 aliasing to f 1? 4.5 (15 points) List the steps (hardware and software) to simultaneously sample (within a few ns) the two analog voltages, sequentially read them into computer memory, and repeat the entire process at the sampling rate of 100 kHz.
PROBLEM 5 (total 30 points) 5.1 (8 points) Compare wireless data interfacing technologies WiFi, Bluetooth and ZigBee in aspects of number of nodes, data throughput rate and battery life. Standard Wi-Fi™ 802.11b Bluetooth™ 802.15. ZigBee® 802.15. Battery Life (long/medium/short) Network Size, # of nodes (big /medium/ small) Data rate (high/medium/low) 5.2 (7 points) Briefly describe situations where each of the three technologies would best be used. 5.3 (15 points) Use the most suitable technology to design a wireless sensor network that allows a wireless base station to read data from 256 wireless end nodes once per second. Each end node has a sensor circuit. These circuits continuously measure physical quantities such as time, temperature, voltage, etc. Assume that
- The base station includes a host PC and a wireless central node.
- The sensors produce 16-bit digital outputs.
- The distances between the central node and the end nodes are less than 50 meters
- The end nodes are powered by 50mAh coin batteries, which must last for at least one year. Sketch your design on the next page, including all devices and their network topology.
PROBLEM 6 (total 25 points) Parts of the body, such as an arm or a leg, weakened by the effects of the stroke, can regain some functionality by repeatedly stretching them (called physical therapy). You are asked to design a real time controller for a robotic physical therapy device. Assume that
- The controller sends analog output signal A1 to control the stretching speed of the robotic device. The stretching speed is proportional to the amplitude of A1. The robotic device rotates in the CCW/CW direction when A1 is plus/minus.
- The controller reads the torque signal back from analog input channel A2. When the absolute value of the torque feedback is larger than a given value, the robotic device must reverse the direction of stretching. . 6.1 (10 points) Draw a block diagram of your interfacing and control system based on the experimental platform you used in your laboratory exercises.
6. 2 (10 points) List the program steps needed to perform the physical therapy motions. 6. 3 (5 points) Describe the potential risk to the patient and how you would reduce the risk.
