AVR Micro-controller Multiple Choice Questions on “LCD Interfacing”.
1. In AVR, the LCD operates in two main modes, it can be in 8 bit or 4 bit data.
a) true
b) false
c) depends on the situation
d) can’t be said
Answer: a
Clarification: In AVR, the LCD operates in two main modes, they are in the 8 bit data transfer mode and the 4 bit data transfer mode.
2. What can be the sequence of commands that may be used for initializing an LCD?
a) 0x06, 0x0e, 0x01
b) 0x0e, 0x01, 0x80
c) 0x38, 0x0e, 0x01
d) all of the mentioned
Answer: c
Clarification: For initializing an LCD, we can use commands like 0x38 for selecting the 5*7 matrix, 0x0e for display on and the cursor blinking and 0x01 for clearing the screen.
3. When the LCD operates in the 4 bit mode, then what more commands are added to it?
a) 33
b) 32
c) 28
d) all of the mentioned
Answer: d
Clarification: When an LCD operates in the 4 bit mode than 33, 32, 28 in hex are sent to it. They represent 3, 3, 3, 2 nibbles which tell the LCD to do into the 4 bit mode for saving the i/o pins of the port.
4. What is the main function of the LPM instruction used in LCD?
a) for initializing the LCD in the read mode
b) for initializing the LCD in the write mode
c) for sending a long string of characters to the LCD
d) all of the mentioned
Answer: c
Clarification: LPM instruction is used for sending a long string of characters to the LCD.
5. The RS pin acts as an
a) input pin
b) output pin
c) any of the mentioned depending on the conditions
d) none of the mentioned
Answer: a
Clarification: The RS pin of the LCD is used for selecting a particular register used for sending a command or the data to the LCD.
6. To latch in information at the data pins of the LCD, we send
a) H-L pulse at the E pin
b) L-H pulse at the E pin
c) A constant H pulse at the E pin
d) A constant L pulse at the E pin
Answer: a
Clarification: For latching in information at the data pins of the LCD, we send a H-L pulse at the LCD.
7. What is the function of the 0x06 command?
a) to clear the LCD
b) to blink the cursor
c) to shift the cursor to the right
d) for selecting the matrix
Answer: c
Clarification: 0x06 command is used for shifting the cursor to the right after every data send to it.
8. What is the address of the second column and the second row of the 2*20 LCD?
a) 0x80
b) 0x81
c) 0xc0
d) 0xc1
Answer: d
Clarification: 0xc0 acts as the address for selecting the second row and the first column of the LCD, so according to it if we need to select the second row and the second column of the LCD, then the address should be 0xc1.
9. Which of the following commands takes more than 100 microseconds to run?
a) shift cursor left
b) shift cursor right
c) set address location of the DDRAM
d) clear screen
Answer: d
Clarification: Clear screen is a command that takes more than 100 microseconds to run.
10. For selecting the data pins in an LCD, RS pin should be
a) 1
b) 0
c) F
d) 10
Answer: a
Clarification: For selecting the data pins of the LCD, the RS pin of the LCD should be set to 1.