Keypad

Diff: Keypad.cpp

Revision:

0:fef7520ff0a6

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Keypad.cpp	Wed Mar 11 14:50:03 2015 +0000
@@ -0,0 +1,109 @@
+#include "Keypad.h"
+
+#include "mbed.h"
+
+// create a Keypad object
+Keypad::Keypad(PinName row1, PinName row2, PinName row3, PinName row4, PinName col1, PinName col2, PinName col3)
+    : rows (row1, row2, row3, row4),cols (col1, col2, col3)
+{
+}
+
+
+
+int Keypad::getKey()
+{
+    //int row_hit = getRowHit(); // get row that was hit (1-4)
+    //int col_hit = getColHit(); // get col that was hit (1-3)
+    char key = decode();
+    last_key_hit = key;
+    return key;
+}
+
+int Keypad::isNewAndPressed() // Is the button a new button press?
+{
+    col_hit = getColHit();
+    row_hit = getRowHit();
+    char key = decode();
+    if (key == last_key_hit) {
+        // No new button has been hit
+        return 0;
+    } else if(key == ' ') { //button has been released
+        last_key_hit = key;
+        return 0;
+    } else {
+        return 1;
+    }
+}
+
+//Private memeber function implementations below
+
+void Keypad::tristate_all()
+{
+    // simulate tri-state by changing mode to PullNone
+    rows.input();
+    rows.mode(PullNone);
+    cols.input();
+    cols.mode(PullNone);
+}
+
+int Keypad::log2(int num)
+{
+    int count = -1;
+    while(num > 0) {
+        num = num >> 1;
+        ++count;
+    }
+    return count;
+}
+
+char Keypad::decode()
+{
+    char dig = ' ';
+    if (row_hit >= 0 && row_hit < 3 && col_hit != -1) {
+        // output the character for buttons 1-9 pressed on the keypad
+        int key_pressed = row_hit * 3 + col_hit + 1;
+        dig = (char)(((int)'0')+key_pressed);
+        return dig;
+    } else if(row_hit == 3) { // the last row was hit
+        switch(col_hit) {
+            case 0 :
+                dig = '*';
+                break;
+            case 1 :
+                dig = '0';
+                break;
+            case 2 :
+                dig = '#';
+                break;
+        }
+    }
+    return dig;
+}
+
+int Keypad::getRowHit()
+{
+    //Set cols to output and output HIGH, read rows for any inputs that are high.
+    cols.output();
+    rows.input();
+    rows.mode(PullDown);
+    wait_ms(100);
+    cols = 0xF;
+    int row_hit = rows.read();
+    tristate_all();
+    row_hit = log2(row_hit);
+    return row_hit;
+}
+
+int Keypad::getColHit()
+{
+    //Set rows to output and output HIGH, read cols for any inputs that are high.
+    rows.output();
+    cols.input();
+    cols.mode(PullDown);
+    wait_ms(100); // Give time to set up pin modes
+    rows = 0xF;
+    int col_hit = cols.read();
+    tristate_all();
+    col_hit = log2(col_hit);
+    return col_hit;
+}