ENGI E1112 Departmental Project: Computer Science/Computer Engineering By Kaiven Zhou, Alex Ge, Anna TengIntroductionTHE LCD DISPLAY1. void lcd_init() 2. void lcd_put_char7(char ch, int col) 3. void lcd_print7(const char *c)Lab 1: A Scrolling Display //By: Abhinav Mishra, Andrew Pope, Yiming Ge, Anna Teng, Will VanArsdall, Kaiven Zhou int strlen(const char *s) { int n; for(n=0; *s!='\0';s++) n++; return n; } int main() { lcd_init(); char test[] = "test"; //the message int len = 0; len = strlen(test); //length of the message int x=0; //the starting position of the first characterwhile(1) { int i, t, j; t=x; for(i=0; i < len; i++) { lcd_put_char7(test[i],t%12); t++; } while(j<50000) j+=1; lcd_print7(" "); //clears the screen j=0; x++; } return 0; }Lab 2: Scanning the Keyboard• Keyboard_init() • Keyboard_column_low(int) • Keyboard_column_high(int) • Keyboard_row_read(int)#define NUM_COLUMNS 7 #define NUM_ROWS 6 const char* keys[44] = {"", "N", "I/YR", "PV", "PMT", "FG", "Amort", "CshFl", "IRR", "NPV", "Bond", "%", "RCL", "INPUT", "(", ")", "+/-", "<-", "", "UP", "7", "8", "9", "/", "", "DOWN", "4", "5", "6", "x", "", "SHIFT", "1", "2", "3", "-", "", "", "0", ".", "=", "+", ""};int keyboard_key() { int i, j; int x = 1; for(i = 0; i < NUM_COLUMNS; i++) { keyboard_column_low(i); for(j = 0; j < NUM_ROWS; j++) { if(!keyboard_row_read(j)) { keyboard_column_high(i); //Resets the current column return x; } x++; } keyboard_column_high(i); } return 0; }Lab 3: Entering and Displaying Numbers • Was a number entered? • Was the change sign key pressed? • Was an operation entered? • Was a garbage key pressed?//By Kaiven Zhou, Yiming Ge, Anna Teng void keyboard_get_entry(struct entry *result) { int inputNumber=INT_MAX; int lastKey=-1,inputOperation=-1,numOfDigits=0; lcd_put_char7(0,'+'); //by default the number is positive while(1) { while(keyboard_key()); //ensure no key is pressed while(lastKey==-1) lastKey = keyboard_key(); //get keyif('0'<=lastKey && lastKey <= '9' && numOfDigits<=MAX_NUM_DIGITS) { if(inputNumber==INT_MAX) inputNumber=0; int integerOfLastKey = lastKey-'0'; //char to int inputNumber*=10; inputNumber+=integerOfLastKey; lcd_put_char7(lastKey,numOfDigits+1); //the newest digit placed should go after the sign and the previous number (which has numOfDigits digits) numOfDigits++; }else if(lastKey == '~') { if(inputNumber==INT_MAX) inputNumber=0; inputNumber*=-1; if(inputNumber<0) lcd_put_char7(0,'-'); else lcd_put_char7(0,'+'); } else if(lastKey=='+'||lastKey=='-'||lastKey=='*'||lastKey=='/'||lastKey=='\r') { result->number = inputNumber; result->operation = inputOperation; return; }Lab 4: An RPN Calculator What is Reverse Polish Notation (RPN)? Normally we would enter (infix notation): 1 + 2 - 3 In Reverse Polish Notation: 1 return 2 + 3 -Lab 4: An RPN Calculator void rpn(int *stack, int *top, struct entry *input) { if(input->number != INT_MAX) //if there is a number, add it to the stack { stack[(*top)] = input->number; (*top)++; } 5 6 Top … Example Stackif( (*top)>1 ) //only do an operation if there are at least 2 numbers in the stack { switch(input->operation) { case '\r‘: break; //done in the first if statement case '+‘: lcd_print_int( stack[(*top)-2] += stack[(*top)-1] ); (*top)--; break; case '-‘: lcd_print_int( stack[(*top)-2] -= stack[(*top)-1] ); (*top)--; break; case '/': lcd_print_int( stack[(*top)-2] /= stack[(*top)-1] ); (*top)--; break; case '*‘: lcd_print_int( stack[(*top)-2] *= stack[(*top)-1] ); (*top)--; break; } } }Our RPN