Diff: DAC/DAC.cpp

Revision:

1:4bd950ab8756

Child:

3:29aa7212dda4

diff -r ce795bcc930d -r 4bd950ab8756 DAC/DAC.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DAC/DAC.cpp	Fri Apr 04 18:48:23 2014 +0000
@@ -0,0 +1,67 @@
+#include "mbed.h"
+#include "mcp4725.h"
+#include "DAC.h"
+#include "math.h"
+#include "log.h"
+
+#define PI 3.1415926
+MCP4725 controller(p9, p10, MCP4725::Fast400kHz, DEVICE_ADDR_BIT);
+Timer DAC_timer;
+
+bool volatile DAC_running = false;
+float p_range = 0;
+enum FREQ p_freq = FREQ_10HZ;
+enum FORM p_form = FORM_SQUARE;
+
+void DAC_start(){
+    DAC_running = true;
+}
+
+void DAC_stop(){
+    DAC_running = false;
+}
+void DAC_set(float range, enum FREQ freq, enum FORM form){
+    p_range = range;
+    p_freq = freq;
+    p_form = form;
+}
+
+void DAC_generate(){
+    float Vout = 0;
+    int time_us = 0;
+    DAC_timer.start();  
+    while( DAC_running ){
+        if( p_form == FORM_SQUARE ){
+            if( p_freq == FREQ_10HZ ){
+                //generate square wave at 10HZ
+                if( (int)time_us % 1000000 <= 500000){ // T = 100 ms
+                    Vout = p_range;
+                }
+                else 
+                    Vout = 0;          
+            }
+            else{
+                //generate square wave at 1HZ               
+                if( (int)time_us % 1000000  <= 500000) //T = 1 s
+                    Vout = p_range;
+                else 
+                    Vout = 0;
+            }
+        }
+        else if ( p_form == FORM_SIN){
+            if( p_freq == FREQ_10HZ ){
+                Vout = p_range / 2.0 * (sin( 2.0 * PI * 10.0 * time_us / 1000000.0) + 1);                
+            }
+            else{
+                //generate sin wave at 1HZ
+                Vout = p_range / 2.0 * (sin( 2.0 * PI * 1.0 * time_us / 1000000.0) + 1);
+            }
+        }
+        wait_us(1000); //delay 1 ms
+        time_us += 1000;
+        controller.write(MCP4725::Normal, (0xFFF * (Vout/VDD_VOLTAGE) ), false);
+    }
+    DAC_timer.stop();
+    DAC_timer.reset();
+    
+}
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