1. Micro Processor Project ECE 300 April 17, 2004 Group 2

2. The Crew Group 2: Ross Chun rchun@utk.edu Andrew R. Geouque ageouque@utk.edu Chin-Yu Hsu (Joe) chus@utk.edu

3. Procedure 1. Soldering the board 2. Testing the board for basic function 3. Sensor selection 4. Implementation of the sensor 5. Configuration of code necessary for the selected sensor 6. Testing of the sensor

4. 1. Soldering Soldering the components onto the board was pretty straight forward Soldering the components onto the board was pretty straight forward Took a little practice with the extra board and the components Took a little practice with the extra board and the components Hardest part was the microprocessor – (had a hard time getting it aligned properly) Hardest part was the microprocessor – (had a hard time getting it aligned properly)

5. 2. Testing the Board Did not run into any problems. The processor was flashed and programmed correctly on the first attempt. Did not run into any problems. The processor was flashed and programmed correctly on the first attempt. Some of the LCD pins had to be re- soldered, but that was about we had to do in order for the board to run the “HELLO” program. Some of the LCD pins had to be re- soldered, but that was about we had to do in order for the board to run the “HELLO” program.

6. The Board This is a picture of the board after all the soldering was done. This is a picture of the board after all the soldering was done. The red input is tied to pin P6.6/a6. The v_o of the sensor will be tied to this input. The red input is tied to pin P6.6/a6. The v_o of the sensor will be tied to this input. The black input is tied to an arbitrary chosen ground on the board. The ground pin of the sensor will be tied to this input. The black input is tied to an arbitrary chosen ground on the board. The ground pin of the sensor will be tied to this input. The blue wire is tied to the board’s VCC pin which will be used as the sensor’s voltage source. The blue wire is tied to the board’s VCC pin which will be used as the sensor’s voltage source.

7. 3. Sensor Selection  We wanted to use some kind of temperature sensor because it seemed like it would be the most practical.  We looked at the temperature sensors suggested in the project manual.  We also visited www.analog.com and did research on some other temperature sensors. www.analog.com  In the end, the analog AD22103 temperature sensor was chosen.

8. The AD22103 Ratio-metric temperature sensor Ratio-metric temperature sensor Sensor’s output voltage is proportional to the power supply voltage. Sensor’s output voltage is proportional to the power supply voltage. 100 °C temperature span 100 °C temperature span (0 °C to + 100 °C ) Accuracy better that ± 2.5% Accuracy better that ± 2.5%

9. The Ad22103 cont. Because the sensor outputs a voltage that is proportional to the temperature, the code necessary to implement this sensor was very simple. Because the sensor outputs a voltage that is proportional to the temperature, the code necessary to implement this sensor was very simple. It can be ordered either as an SO-8 (SOIC) pin configuration or a TO-92 pin configuration. It can be ordered either as an SO-8 (SOIC) pin configuration or a TO-92 pin configuration. It was obvious to choose the TO-92 3 pin design because it was much easier to make connections with the board. It was obvious to choose the TO-92 3 pin design because it was much easier to make connections with the board.

10. 4. Implementation of the Ad22103 A small circuit board was purchased along with a 3 prong-plug to create a mounting base for the sensor. Wires were also soldered to the board for easy connections. A small circuit board was purchased along with a 3 prong-plug to create a mounting base for the sensor. Wires were also soldered to the board for easy connections.

11. 5.Configuration of the Code The code that had to be written in order for the Ad22103 to work was was very simple. The code that had to be written in order for the Ad22103 to work was was very simple. Only a few lines of code had to be added to the given sensor.c file. Only a few lines of code had to be added to the given sensor.c file.

12. Code Continued…  After studying the data sheet and the given sensor.c file, we realized that the majority of the work was already done for us.  The only thing that had to be done was create code that would solve for the correct value of T_a and display the correct value on the LCD. V_out = (V_s/3.3 V) x [0.25 V + (28.0 mV/ °C ) x T_a]  V_s = 2.86 V which was the voltage provided by the V_cc from the board.  V_out = sample which is already a known value from the given sensor.c file

13. More on the Code… This was the code that had to be implemented to solve for the values of Celsius and Fahrenheit. As you can see to the code on your left, we declared two new variables Cel and Fah to denote the values of temperature in both scales.

14. Extra Information on the Code We realized that the refresh rate on of the board was quite slow and we wanted to see if there is any way we could change the rate so it would be a little faster. We realized that the refresh rate on of the board was quite slow and we wanted to see if there is any way we could change the rate so it would be a little faster. We looked at and try to understand the delay.C and lcd.C files, but we were unable to locate where the refresh rate was located. We looked at and try to understand the delay.C and lcd.C files, but we were unable to locate where the refresh rate was located. The refresh rate is located in the sensor.C file and we thought that all we had to do was change the value to something a little smaller. However, this was not the case. The refresh rate is located in the sensor.C file and we thought that all we had to do was change the value to something a little smaller. However, this was not the case.

15. Some Info on #Define BT_ADLY Did a little google search and this is what we found. Did a little google search and this is what we found. There are only a set of certain values that can be used with this definition. There are only a set of certain values that can be used with this definition.

16. 6. Testing After some debugging and re-soldering of some lose pin connections the sensor worked properly. After some debugging and re-soldering of some lose pin connections the sensor worked properly. The refresh rate of 1000 ms seemed to be pretty good and another version of code was created in order to display temperature in Celcius and Fahrenheit. The refresh rate of 1000 ms seemed to be pretty good and another version of code was created in order to display temperature in Celcius and Fahrenheit.

17. Testing… Here is a picture of the working board and sensor. Here is a picture of the working board and sensor.