ECE 300 – Spring 2007 Christopher Boyd Anusha Gattupalli Timothy Poore Project Assignment Groups were assigned in class. Leaders for each group were specified. Dr. Green then described how to go about doing the project. He specified what parts we would need and where we could get them. He also gave us equipment to use like the microscope and soldering iron. Getting the Parts We ordered 3 MSP430F449PZ chips from Texas Instruments. (free samples) We then purchased a kit for the project at the Ferris Hall Parts Store for $15. After we started working on the project, we decided upon what types of sensors we wanted and ordered free samples from Analog Devices. Project Goals Over the course of the project, we were expected to learn how to work as a team. Learn how to solder components like the capacitors and the chip onto the board. Design a circuit to make the sensor work. Program the chip to analyze the voltage from the sensor and display the appropriate output on the LCD. Soldering Capacitors and resistors were mounted first, to give us experience with soldering. We paid close attention to the direction that the polarized capacitors were facing. Next we soldered the chip on the board. It would have been more difficult to solder the chip on after the other parts were placed on the board. Soldering the Chip The chip has 25 pins on each side. There are four ½ inch sides. We had to apply pressure to each pin as we soldered it, in order to make sure a good connection was made. On one side, the pins needed to be bent slightly in order to make a connection with the trace on the board. Soldering (continued) After we soldered the chip, we went through and made sure that each of the 100 pins were properly connected. Then we soldered all the other components like the JTAG connector and the LCD. Finally, we mounted the voltage jacks and soldered the wires to the appropriate spots on the board. Programming the Chip First we tried to load the “Hello” program to the chip. However, there were problems. Checked all the pins of the chip (again) to make sure they were soldered on. After that, it still didn’t work. Turns out the computer had a faulty parallel port. Building the Sensor Circuits Dr. Green had sent out an email with the schematic for AD590 sensor circuit. We built it exactly like the schematic. After tweaking the resistor pots appropriately, it worked with Dr. Green’s sensor program. Next was the AD22103, which was simpler to set up (provided you don’t have it reversed.) AD22103 Program Using the equation that we were given: Vout=(Vs*3.3V)*[.25V+.028V/°C*Ta] We plugged in Vs which was 2.869V coming from the sensor board, and then solved for Ta. This gives us: T=41.0795*Vo-8.9286 (°C) However, Vo then had to be multiplied by a scaling factor of .61. AD22103 (continued) In addition to the scaling factor for Vo, the value was 100x what it should be, which was appropriate since this is needed for the LCD display. However, this meant that any value added to or subtracted from the Vo needed to be multiplied by 100. AD22103 Chart Any Questions?