EE345M Spring 2002 Quiz 2 Page 1 of 3Jonathan W. Valvano First:_________________ Last:_____________________April 10, 2002, 9:00 to 9:50 amThis is an open book, open notes exam. You must put your answers on these pages only. You can use theback. You have 50 minutes, so please allocate your time accordingly. Please read the entire quiz before starting.(30) Question 1. The following is a simple IIR digital filter.y(n) = 0.70x(n) -0.65x(n-1) +0.15x(n-2) -0.5y(n-1) +0.25y(n-2)The unsigned 8-bit input data (from A2D(0)) is bounded between 0 and 255. You may assume the filter gain is lessthan one, so the y(n) values are also bounded between 0 and 255. No floating-point calculations are allowed. Forfull credit you must implement the filter without approximation. Be careful to specify whether you use 16 or 32-bitinteger math. Assume TMSK2 contains its initial value of 0. Specify the CONSTANT required for 1000 Hz sampling.unsigned char x[3],y[3]; // 8-bit unsigned numbers, 0 to 255#pragma interrupt_handler TC5Handler()#define CONSTANT // fill in the value here to make fs equal to 1000Hzvoid TC5Handler(void){ TFLG1 = 0x20; // ack interrupt TC5 = TC5+CONSTANT; // fs=1000Hz // add code here to shift the MACQ x[0] = A2D(0); // new 8-bit data, 0 to 255// add code here to execute the filter}#pragma abs_address: // fill in the vector herevoid (*OC5_vector[])() = { TC5Handler};#pragma end_abs_addressEE345M Spring 2002 Quiz 2 Page 2 of 3(30) Question 2. Design an analog circuit that has the transfer function Vout = 4 V1 – 10 V2 + 5. V1 and V2 areanalog inputs, and Vout is the analog output. You do not need to worry about input or output impedance. Yourcircuit will operate on a ±12 V supply using REF02 references and OP07 op amp(s). The REF02 creates a +5.00reference voltage. Full credit will be given to proper solutions using one REF02 and one OP07 op amp. Show theanalog circuit. Label all resistor values. You do not need to show the power supply connections for the OP07 andREF02.EE345M Spring 2002 Quiz 2 Page 3 of 3(40) Question 3. In this problem, you will design an instrument to measure weight using the Maxim MAX1247.The range of weight is 0 to 400 lbs. Because you are using a 12-bit ADC and the system is linear, the measurementprecision will also be 12 bits. The frequencies of interest are 0 to 1 Hz. The weight is measured with 4 resistivestrain gages placed in a bridge, two in compression (100-∆R), two in expansion (100+∆R). The sensitivity of eachgage is 0.005 Ω/lbs. The change in transducer resistance, ∆R, is linearly related to weight.(10) Part a) Complete the following table. Data is the digital result from the unsigned 12-bit ADC. The systemwill use the full scale 0 to +2.5V ADC range. Refer to the circuit in part c). W∆RR1R2R3R4V1V2V1-V2 V3Data 00100 100 100 100 0.00 200 199101 101 99 1.25 400 298102 102 98 2.50 lbs Ω Ω Ω Ω Ω V V V V(5) Part b) What sampling rate would you choose? Why?(5) Part c) Specify the desired gain for the instrumentation amp.Max12476812AD620+5.00VR3V1V2V3R1R2R4RfSPI(5) Part d) Specify the Rf resistor that implements that gain.(5) Part e) What is the maximum allowable noise of the analog circuit, referred to its input (at V1, V2)?(5) Part f) What is the measurement resolution in lbs?(5) Part g) Floating point is not available. The software will perform many mathematical calculations on themeasurement. What number format would you suggest be used to represent the weight? Be as specific as