Diff: MAX7456.cpp

Revision:

0:972f5da423fd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX7456.cpp	Fri Aug 20 12:45:19 2010 +0000
@@ -0,0 +1,137 @@
+#include "mbed.h"
+#include "MAX7456.h"
+
+namespace mbed {
+
+
+
+MAX7456::MAX7456(PinName mosi, PinName miso, PinName clk, PinName ncs, PinName nrst, const char* name)
+        : Stream(name), _spi(mosi, miso, clk), _ncs(ncs), _nrst(nrst) {
+                                
+// initialisation code here
+
+   _nrst = 0;   
+   wait (0.5);   
+   _nrst = 1;   
+   wait (0.5);
+
+   // Setup the spi for 8 bit data, high steady state clock,
+   // second edge capture
+   _spi.format(8,0);
+
+   // 1MHz clock
+   _spi.frequency(1000000);
+
+
+}
+
+
+
+
+void MAX7456::cls() {
+    int tmp=0;
+    tmp = _read(DMM);
+    tmp &= 0xFB;
+    _write(DMM,tmp);  //Make sure that DMM[2]=0 so that there can be write operations
+
+    tmp = _read(DMM);
+    tmp |= 0x04;
+    _write (DMM,tmp);   //set DMM[2]=1 to clear all locations
+
+    // should wait until DMM[2] goes back to zero, so we know the reset it finished
+
+}
+
+
+void MAX7456::locate(int x, int y) { //not sure if I understand the last line
+    if ( (x<30) && (y<16) ) {
+        int add = y*30+x; //formula for converting coordinates into denary location
+        _write(DMAL,add);
+        _write(DMAH,add>>8); // what does the ">>" mean?
+    }
+}
+
+
+
+int MAX7456::_getc(int character) {
+    for (int i = 0 ; i < 479 ; i++) { 
+        int location= _read(DMDI,i)
+        
+        if((location == character - 0x30){ //characters from 1-9
+            found= "true";
+            }
+        else if(location == character - 0x36){ // characters from A-Z
+            found = "true";
+            }
+        else if(location == character - 0x3C){ // characters from a-z
+            found = "true";
+            }
+        else if(location == character + 0x17){ //brackets ()
+            found = "true";
+            }    
+        else{
+            found = "false";
+        
+        if found = "true"{
+            return(i);
+            }
+        else{
+            return("character not found");
+    }
+}
+
+
+int MAX7456::_putc(int c) {
+    
+    if((c >= 0x31)&&(c <= 0x39)) { //characters from 1-9
+        c= c-0x30;
+        }
+    if((c >= 0x41)&&(c <= 0x5A)){ // characters from A-Z
+        c= c-0x36;
+        }
+    if((c >= 0x61)&&(c <= 0x7A)){ // characters from a-z
+        c= c-0x3C;
+        }
+    if((c == 0x28)&&(c == 0x29)){ //brackets ()
+        c= c + 0x17;
+        }    
+    _write(DMDI,c);
+    return(c);
+}
+
+
+
+
+void MAX7456::vtrim(int v) {
+}
+
+void MAX7456::htrim(int h) {
+}
+
+void MAX7456::format(char mode){
+    if (mode == "P"){
+        write(VM0,0x78);  // internal sync, OSD enable, PAL
+        }
+}        
+
+int MAX7456::_read(int address) {
+ // force bit 7 to 1 for a read
+    address |= 0x80;
+    _ncs=0; // select device
+    _spi.write(address);          // send address
+    int value = _spi.write(0x00); // send dummy
+    _ncs=1; //deselect device
+    return (value);
+}
+
+void MAX7456::_write(int address, int data) {
+   // force bit 7 to 0 for a write
+   address &= 0x7f;
+   // select the device
+   _ncs = 0;
+   // write VM1    
+   _spi.write(address); // send address
+   _spi.write(data); // send some data
+   // Deselect the device
+   _ncs = 1; 
+}