Diff: keyboard.cpp

Revision:

9:311b6676272d

Parent:

8:dd258f9e24b0

Child:

10:5706b75d40fa

--- a/keyboard.cpp	Wed Jul 09 07:52:00 2014 +0000
+++ b/keyboard.cpp	Fri Jul 11 11:08:02 2014 +0000
@@ -2,6 +2,10 @@
 #include "mbed.h"
 #include "keyboard.h"
 
+const int CDU_KB_ADRS  = 0x68;  //Base addrees TCA8418 keypad scanner
+const int ACK  = 0x00;
+const int NACK = 0x01;
+
 extern int key_hit_ID;
 //extern mbos CDU_OS;
 
@@ -22,17 +26,68 @@
 
 void CDU_KB_COMM_INIT()
 {   //initialize communication with TCA84818
-    CDU_I2C.write(CDU_KB_WRITE); //initiate write cycle
-    //intialize all registers from TCA8418 here
-    CDU_I2C.read(CDU_KB_READ); //start reading from TCA4818
+    char cmd[2];
+    cmd[0] = REG_CFG; //pointer byte to CFG register
+    cmd[1] = 0x01; //data for CFG register KE_IEN set to 1
+    if ( CDU_I2C.write(CDU_KB_ADRS,cmd, 2) == ACK ) //initiate write cycle and check for ACK
+    {
+        //intialize all registers from TCA8418 here
+        cmd[0] = REG_INT_STAT; //pointer byte to Interrupt Status Register
+        cmd[1] = 0x01; //Reset KE-INT flag      
+        CDU_I2C.write(CDU_KB_ADRS,cmd, 2 );  //Write to Interrupt Status Register from TCA4818 
+        
+        //Set TCA8418 to Keypad mode
+        cmd[0]=REG_KP_GPIO1; //KP_GIO1
+        cmd[1]=0xFF; //Set to Keypad mode
+        CDU_I2C.write(CDU_KB_ADRS,cmd, 2);
+       
+        cmd[0]=REG_KP_GPIO2; //KP_GIO2
+        cmd[1]=0xFF; //Set to Keypad mode
+        CDU_I2C.write(CDU_KB_ADRS,cmd, 2);
+      
+        cmd[0]=REG_KP_GPIO3; //KP_GIO3
+        cmd[1]=0xFF; //Set to Keypad mode
+        CDU_I2C.write(CDU_KB_ADRS,cmd, 2);
+       
+    }
+    else
+    {
+        //No response from TCA8418 keyboard chip
+        FAIL = 1; //Switch on FAIL indicator
+    }  
 }
 
 void CDU_KB_GET_KEY()
 {
-    CDU_I2C.write(CDU_KB_READ); //initiate read cycle
-    key_hit_ID = CDU_I2C.read(CDU_KB_READ)  ;    //read key value
+    EXEC = 1;//flash EXEC leds when key pressed....
+    wait( 0.1 );
+    EXEC = 0;
+    
+    char cmd[2];
+ 
+    //Read interrupt status flag
+    cmd[0] = REG_INT_STAT; //pointer byte to Interrupt Status Register
+    CDU_I2C.write(CDU_KB_ADRS, cmd, 1); //initiate read cycle
+    CDU_I2C.read(CDU_KB_ADRS, cmd, 1);  //read key value
+    
+    //Read Key Lock and Event Counter
+    cmd[0] = REG_KEY_LCK_EC; //pointer byte KEY_LCK_EC
+    CDU_I2C.write(CDU_KB_ADRS, cmd, 1); //initiate read cycle
+    CDU_I2C.read(CDU_KB_ADRS, cmd, 1);  //read key value
+    
+    //Keypress --> read data from keybuffer
+    cmd[0] = REG_KEY_EVENT_A; //pointer to Key Event Register KEY_EVENT_A
+    CDU_I2C.write(CDU_KB_ADRS, cmd, 1); //initiate read cycle
+    CDU_I2C.read(CDU_KB_ADRS, cmd, 2);  //read key value (=2 words)
+
+    //Reset interrupt flag
+    cmd[0] = REG_INT_STAT; //pointer byte to Interrupt Status Register
+    cmd[1] = 0x01; //Reset KE-INT flag
+    CDU_I2C.write(CDU_KB_ADRS,cmd, 2 );
+
     //CDU_OS.SetEvent(KEY_EVENT,SEND_KEYMESSAGE_TASK_ID ); //Set event key to wakeup task
-    } 
+
+} 
 
 void CDU_KB_INT_START()
 {
@@ -67,7 +122,15 @@
         case 255:
         {
             //calculate percentage from potmeter value
-            BGL_LED = ( 0.0 + 100*BGL_POT );
+        if ( BGL_POT < 0.01 )
+            {
+                BGL_LED = 0.0; //prevents flickering when low intensity
+            }
+        else
+            {
+                BGL_LED = BGL_POT; 
+            }
         }
     }
 }          
+