added change ardiuno code

section01/Lec05/change_lcd/change_lcd.ino

+#include <LiquidCrystal.h>
+#include <stdio.h>
+
+LiquidCrystal lcd(8,9,4,5,6,7);
+
+struct change{
+    int quarters;
+    int dimes;
+    int nickels;
+    int pennies;
+};
+
+struct change *make_change(float amount)
+{
+    int cents = amount * 100;
+    struct change *c = (struct change *)malloc(sizeof(*c));
+    c->quarters = 0;
+    c->dimes = 0;
+    c->nickels = 0;
+    c->pennies = 0;
+
+    while (cents > 0){
+	if (cents >= 25) {
+	    c->quarters++;
+            cents -= 25;
+        } else if (cents >= 10) {
+            c->dimes++;
+            cents -= 10;
+        } else if (cents >= 5) {
+            c->nickels++;
+            cents -= 5;
+        } else {
+            c->pennies = cents;
+            cents = 0;
+        }
+    }
+
+    return c;
+}
+
+void sprint_change(char* line1, char* line2, struct change* c)
+{
+    sprintf(line1, "%3d qtr, %d dme",
+                c->quarters, c->dimes);
+                
+    sprintf(line2, "%3d nkl, %d pny",
+                c->nickels, c->pennies);
+}
+
+void setup() {
+  lcd.begin(16,2);
+  lcd.setCursor(0,0);
+}
+
+void loop() {
+  static float amount = 0.0;
+  char line1[30], line2[30];
+  
+  struct change *c = make_change(amount);
+  amount += 0.01;
+  
+  sprint_change(line1, line2, c);
+  
+  lcd.clear();
+  lcd.setCursor(0,0);
+  lcd.write(line1);
+  lcd.setCursor(0,1);
+  lcd.write(line2);
+  free(c);
+  
+  delay(500);   
+}

section01/Lec05/hello_lcd_c/hello_lcd_c.ino

-#include <LiquidCrystal.h>
-#include <stdio.h>
-
-
-static FILE uartout = {0};
-
-LiquidCrystal lcd(8,9,4,5,6,7);
-
-static int uart_putchar(char c, FILE *stream)
-{
-  Serial.write(c);
-  return 0; 
-}
-
-void setup() {
-  // put your setup code here, to run once:
-  Serial.begin(9600);
-  fdev_setup_stream(&uartout, uart_putchar, NULL, _FDEV_SETUP_WRITE);
-  stdout = &uartout;
-  printf("startup\n");
-  
-  
-  lcd.begin(16,2);
-  lcd.setCursor(0,0);
-  lcd.write("hello"); 
-
-}
-
-void loop() {
-  // put your main code here, to run repeatedly:
-  printf ("hello\n");
-  delay(500);
-}