Revision 1:4bd950ab8756, committed 2014-04-04

Comitter:

dzl5187

Date:

Fri Apr 04 18:48:23 2014 +0000

Parent:

0:ce795bcc930d

Commit message:

dac sub-system;

Changed in this revision

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();
+    
+}
\ No newline at end of file

diff -r ce795bcc930d -r 4bd950ab8756 DAC/DAC.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DAC/DAC.h	Fri Apr 04 18:48:23 2014 +0000
@@ -0,0 +1,39 @@
+
+#ifndef DAC_H
+#define DAC_H
+
+#include "mbed.h"
+#include "mcp4725.h"
+
+//pins for connection
+#define PIN_SDA p9
+#define PIN_SCL p10
+#define DEVICE_ADDR_BIT 0
+//ref voltage
+#define VDD_VOLTAGE 5.04
+
+enum FREQ { FREQ_10HZ, FREQ_1HZ};
+enum FORM { FORM_SQUARE, FORM_SIN};
+
+/**
+    Funciton: DAC_start
+    Description: start generating the analog signal
+*/
+void DAC_start();
+/**
+    Funciton: DAC_stop
+    Description: stop generating the analog signal
+*/
+void DAC_stop();
+/**
+    Funciton: DAC_generate
+    Description: calculate the Vout accoding to the configuration and send command to DAC chip
+*/
+void DAC_generate();
+/**
+    Funciton: DAC_set
+    Description: set the configuration( amplitude, frequency and form of the signal)
+*/
+void DAC_set(float range, enum FREQ freq, enum FORM form);
+
+#endif
\ No newline at end of file

diff -r ce795bcc930d -r 4bd950ab8756 DAC/MCP4725.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DAC/MCP4725.lib	Fri Apr 04 18:48:23 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/dzl5187/code/MCP4725/#35e3e80b804c

diff -r ce795bcc930d -r 4bd950ab8756 log/log.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/log/log.cpp	Fri Apr 04 18:48:23 2014 +0000
@@ -0,0 +1,27 @@
+#include "log.h"
+#include "stdio.h"
+#include "mbed.h"
+#include "stdarg.h"
+Serial pc(USBTX, USBRX);
+void vlogMessage(const char *,va_list);
+/**
+    Function: logMessage
+    Description: output the message(can be formatted string) to PC
+*/
+void logMessage(const char *fmt,...){
+    va_list args;
+    va_start(args, fmt);
+    vlogMessage( fmt, args );
+    va_end(args);
+}
+
+void vlogMessage(const char *fmt,va_list args){
+    char buffer[255];
+    char msg[255];
+    //get time stamp
+    sprintf(buffer, "Time[seconds]: %.3f : ", programTimer.read_ms()/1000.0);
+
+    vsprintf( msg, fmt, args );
+    strcat( buffer, msg);
+    pc.printf("%s \n", buffer);
+}

diff -r ce795bcc930d -r 4bd950ab8756 log/log.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/log/log.h	Fri Apr 04 18:48:23 2014 +0000
@@ -0,0 +1,14 @@
+
+#ifndef LOG_H
+#define LOG_H
+#include "mbed.h"
+
+
+extern Timer programTimer;
+
+/**
+    Function: logMessage
+    Description: output the message(can be formatted string) to PC
+*/
+void logMessage(const char *fmt,...);
+#endif
\ No newline at end of file

diff -r ce795bcc930d -r 4bd950ab8756 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Apr 04 18:48:23 2014 +0000
@@ -0,0 +1,19 @@
+#include "mbed.h"
+#include "log.h"
+#include "DAC.h"
+#include "mcp4725.h"
+Timer programTimer;
+//Timer DACC_timer;
+//DigitalOut testLed(LED1);
+
+int main()
+{
+    
+    DAC_set(3.0, FREQ_1HZ, FORM_SQUARE);
+    DAC_start();
+    while(1) {
+        DAC_generate();
+    }
+    
+
+}
\ No newline at end of file