Diff: SoftMCP4922.cpp

Revision:

0:aeca3abe0194

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SoftMCP4922.cpp	Mon Oct 28 12:08:13 2013 +0000
@@ -0,0 +1,93 @@
+/*
+ * MCP4922 (Soft SPI) Library
+ * 2013 Magnetone
+ */
+ 
+#include "SoftMCP4922.h"
+
+SoftMCP4922::SoftMCP4922( PinName sck, PinName sdi, PinName cs, PinName ldac, PinName shdn, int ch):
+    m_sck( sck ),
+    m_sdi( sdi ),
+    m_cs( cs ),
+    m_ldac( ldac ),
+    m_shdn( shdn ),
+    m_ch( ch )
+{
+    
+    m_shdn = 1; // non shutdown
+    m_sck = 0;  // init
+    
+    // out vcc/2
+    write_u12( 2048 );
+    
+}
+
+void SoftMCP4922::write_u16( unsigned short value )
+{
+    dacControl( value >> 4 );
+}
+
+void SoftMCP4922::write_u12( unsigned short value )
+{
+    dacControl( value );
+}
+
+void SoftMCP4922::write_u10( unsigned short value )
+{
+    dacControl( value << 2 );
+}
+
+void SoftMCP4922::write_u8( unsigned char value )
+{
+    dacControl( value << 4 );
+}
+
+// DAC control function
+void SoftMCP4922::dacControl( unsigned char value )
+{
+     int i ;
+
+    // dac setting start
+    m_cs = 0;
+    m_ldac = 1;
+    
+    // channel select
+    if( m_ch == 0 ){
+        m_sdi = 0;
+    }else{
+        m_sdi = 1;
+    }
+    m_sck = 1;
+    m_sck = 0;
+    
+    // vref buffer off
+    m_sdi = 0;
+    m_sck = 1;
+    m_sck = 0;
+    
+    // output gain = 1
+    m_sdi = 1;
+    m_sck = 1;
+    m_sck = 0;
+    
+    // analog output enable
+    m_sdi = 1;
+    m_sck = 1;
+    m_sck = 0;
+     
+    // DAC data out
+    for (i=11 ; i>=0 ; i--) {
+        if ( ( ( value >> i ) & 0x1 ) == 1 )
+            m_sdi = 1;
+        else
+            m_sdi = 0;
+        m_sck = 1;
+        m_sck = 0;
+    }
+
+    // analog out
+    m_cs = 1;
+    m_ldac = 0;
+    
+}
+