The SPI Function - The HCS12/9S12: An Introduction to Software and Hardware Interfacing - page 527

10.15 Lab Exercises and Assignments

L10.1 Use the Freescale seven-segment display driver MC14489 (with SPI interface) to drive
fi ve seven-segment displays, and write a program to display the following pattern forever:
0
10
210
3210
43210
54321
65432
76543
87654
98765
09876
10987
21098
32109
go to the fifth pattern (43210) and repeat.
L10.2 Use the TC72 to measure the ambient temperature and the LCD on the demo board to
display the current temperature:
1. Write a program to read the temperature once every 200 ms and display the new
temperature reading on the LCD in two rows:
Temperature is
XXX.X

C
2. Change the ambient temperature using your hand, hot water in a plastic bag, ice in a
plastic bag, and so on, to touch the TC72 and record the temperature reading.
L10.3 Use one MAX6952 and four matrix displays (e.g., common-cathode-row Fairchild
GMC7175C) to perform the operation described in Exercise E10.12.
L10.4 Use the 12-bit DAC (MCP4922) to generate a sinusoidal waveform by dividing one cycle
(360°) into 60 points. Take the output voltage from the V OUTA pin and display the waveform
using an oscilloscope.
L10.5 Use the 8-kBit EEPROM 25AA080B from Microchip to interface with the HCS12 using
the SPI pins. Perform the following operations:
Step 1
Store the string “ The 25AA080B ” in the 25AA080B EEPROM starting the address 0x0000 to
0x000B.
Step 2
Read out the previous string from the EEPROM and display it on the first row of
the LCD.
Step 3
Store the string “ has SPI interface ” in the 25AA080B starting from the address 0x0100 to
0x010F.
Step 4
Read out the previous string and display it on the second row of the LCD.

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