Class for AD7390, a 12 bit SPI driven external DAC from Analog Devices.

Dependencies:   mbed

Datasheet - http://www.analog.com/static/imported-files/data_sheets/AD7390_7391.pdf

Files at this revision

API Documentation at this revision

Comitter:
cassar10
Date:
Sun Apr 13 19:45:35 2014 +0000
Parent:
4:0c327b37ddc1
Commit message:
Set SPI Frequency during initialization. Test program includes for loop to ramp up to reference voltage.

Changed in this revision

AD7390.cpp Show annotated file Show diff for this revision Revisions of this file
AD7390.h Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
--- a/AD7390.cpp	Sun Apr 06 20:19:56 2014 +0000
+++ b/AD7390.cpp	Sun Apr 13 19:45:35 2014 +0000
@@ -1,37 +1,39 @@
 # include "AD7390.h"
 #include "mbed.h"
 
-AD7390::AD7390(SPI& _spi, PinName resetpin, PinName latchpin) : //Mosi, sclk 2x digital out refV, previously missed scope operator.
+AD7390::AD7390(SPI& _spi, PinName resetpin, PinName latchpin) : //Mosi, sclk 2x digital out refV
     spi(_spi),reset(resetpin), latch(latchpin){
     }
-    void AD7390::Init()
+    void AD7390::Init(int Frequency)
     {
         //Vout = (Vref*D)/2^n
+        spi.frequency(Frequency);
         spi.format(12,0);
-        latch = 1;                                      //Pull low to pass shift register to DAC register
+        latch = 1;                                              
+        reset = 0;
         reset = 1;
     }
     
-    void AD7390::Reset()                                //Reset ADC to 0V by pulling reset pin low
+    void AD7390::Reset()                                        
     {
         reset = 0;
-        reset = 1;                                      //Set back to high so it can be written to again
+        reset = 1;                                              
     }
-    void AD7390::Latch()                                //Latch data from shift register to DAC
+    void AD7390::Latch()                                        
     {
         latch = 0;
         latch = 1;
     }
-    void AD7390::Write(float Volts, float RefV)                     //write will require seperate latch after
+    void AD7390::Write(float Volts, float RefV)                 //write will require seperate latch after
     {
         unsigned int send = 0x0000;
         send = (unsigned int) (4096/RefV)*Volts;
         spi.write(send);
     }
-    void AD7390::WriteL(float volts, float RefV)                    //Same as write but with latch attached
+    void AD7390::WriteL(float volts, float RefV)                //Same as write but with latch attached
     {
         unsigned int Send = 0x0000;
-        Send = (unsigned int) (4096/RefV)*volts;      //parse float into unsigned int to send to DAC
+        Send = (unsigned int) (4096/RefV)*volts;                //parse float into unsigned int to send to DAC
         spi.write(Send);
         latch = 0;
         latch = 1;
--- a/AD7390.h	Sun Apr 06 20:19:56 2014 +0000
+++ b/AD7390.h	Sun Apr 13 19:45:35 2014 +0000
@@ -3,14 +3,14 @@
 
 #include "mbed.h"
 
-class AD7390    {           //Create an AD7390 instance
+class AD7390    {                                                //Create an AD7390 instance
     SPI& spi;
     DigitalOut reset, latch;
     public:
         AD7390(SPI& spi, PinName resetpin, PinName latchpin);    //RefV set up for user reference voltage
         void Reset();
         void Latch();
-        void Init();
+        void Init(int Frequency);                                //Set SPI frequency during initialisation
         void Write(float Volts, float RefV);
         void WriteL(float volts, float RefV);
     private:
--- a/main.cpp	Sun Apr 06 20:19:56 2014 +0000
+++ b/main.cpp	Sun Apr 13 19:45:35 2014 +0000
@@ -3,22 +3,15 @@
 
 SPI spi(p5,p6,p7);
 AD7390 Test(spi,p10,p11);
-DigitalOut Led(LED1);
 
 int main(){
-    Test.Init();
+    Test.Init(10000000);
 while (true){
     Test.Reset();
-    Test.WriteL(2.5,3.3);
-    Led = 1;
-    wait(5);
-    Test.Reset();
-    Led = 0;
-    Test.WriteL(1.5,3.3);
-    Led = 1;
-    wait(5);
-    Led = 0;
-    
+    for (float V = 0; V !=3.3; V=V+0.005){
+        Test.WriteL(V,3.3);
+        wait(0.02);
+    }
 
 }
 }