MSP 430 Project ECE 300 Spring 2004

							MSP 430 Project
ECE 300
Spring 2004

      William S. McLemore
       Ruben D. Briano
        Cheng-Han Tsai
Purpose of this Project
   Have an opportunity to work as member of a
    team.
   Learn basic skills of soldering
   Learn to compile program in order to flash
    the computer chip
   Select and study the characteristic of a sensor
   Learn to calibrate the chosen sensor in order
    to get accurate readings through the
    computer chip and to the LCD
Process of Building the Project
   Solder all components to the board
   Test the board by flashing demo file
   Create working circuit between board
    and sensor
   Change and correct the code to display
    wanted results
   Test sensor and board together in
    various cases
Soldering Order
   Surface mounted capacitors and
    resistors
   Push button switch, voltage regulator, 5
    volt input, and slider switch
   MSP430 chip
   LCD
   JTAG connector
Steps for Programming the
MSP430 Chip
   Copy the files from the ECE 300 website
   Create a new project in the IAR software
   Add the Delay, Demo, and LCD files to the
    project
   Compile the project and then select the
    Debugger
   Open the lcdDisplay and select f430p
   Now the chip has been flashed and it should
    scroll ‘HELLO’ across LCD display.
    Choosing a Sensor
Sensor   Linear   Input Output Accuracy Temp.
                                 (+/-)  Range
                              (deg C) (deg C)
AD590            Voltage Current   0.5   -55 - 150

LM19             Current Voltage   3.5   -55 - 130

 DS56             Voltage Voltage   3.0   -40 - 125

AD7818           Voltage Voltage   1.0   -55 - 125
AD590 Temperature Sensor
Features
                 Linear current output
                 Wide Temperature Range:
                  -55°C to 150 °C
                 4 V to 30 V supply
                  voltage range allows for
                  versatility
                 Very accurate when
                  compared to other
                  sensors
                 Output current is not
                  dependant on the exact
                  value of the input voltage;
                  as long as it is within the
                  specified range, the
                  current will be the same
Graph of the Input vs. the Output
                    Linear relationship
                     between the output
                     current and input
                     voltage.
                    Anywhere between
                     the specified voltage
                     range, the output
                     current is proportional
                     to the temperature in
                     Kelvin, equal to 1
                     micro-amp per Kelvin
  Schematic of Our First Circuit
                     This schematic was
                      highly unstable
                     Measured the
        AD590         correct room
                      temperature
 9V
                     Jumped around
1Kohm                 randomly when an
          Vo
                      ice cube was placed
                      on it, varying
                      from –20ºC to 58ºC
Schematic of Circuit
             1 kOhms
                               Operating voltage used
     AD590                      for the op amp is 9V
                               This schematic gave the
                                most stable results
                               Gives the room
9V                     Vo       temperature and went
                                down to 1ºC when an
                                ice cube was placed on
                                it.
                               The Vo is tied into the
                                board
   Block Diagram

                              Op Amp
 9V
            AD590              And
Battery
                              Resistor



     LCD            MSP 430
Intelligent Sensor Microcode
Initializations


            Input


                  Convert data

                        Send Voltage
                      MSP 430 Processor


                                   Output
        Source Code
sample = ADC12MEM6;
X = sample;
Y = .2*(X+X1+X2+X3+X4);   // moving average filter
X4 = X3;
X3 = X2;
X2 = X1;
X1 = X;
Y = Y – 3756.2;           // Y – offset
Y = Y * 10.1;
lcd_word(Y,2);
lcd_char(0,’C’);          // displays a ‘C’ for Celsius
    Complications
   Between the time that we got our board
    to flash and connected to our sensor,
    some of the pins on the chip came loose,
    and we had to re-solder some of the pins.
   Our first op amp was bad and gave us
    unstable results. We switched it with
    another one, which gave us better results.
Picture of the Board and
Circuit
Sources
   Analog Devices:
       http://www.analog.com/
   The University of North Florida College
    of Computing, Engineering, and
    Construction:
       http://www.unf.edu/ccec/