Diff: DAC_MCP4922.cpp

Revision:

0:6e0ed5adfe47

Child:

2:2a3b4ed3eb58

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DAC_MCP4922.cpp	Mon Oct 20 03:01:11 2014 +0000
@@ -0,0 +1,63 @@
+//------------------------------------------------------
+// Class for single DAC in MCP4922
+//
+// 2014/09/29, Copyright (c) 2014 MIKAMI, Naoki
+//------------------------------------------------------
+
+#include "DAC_MCP4922.hpp"
+
+namespace Mikami
+{
+    DAC_MCP4922::DAC_MCP4922(DAC dac, PinName mosi, PinName sclk,
+                             PinName cs, PinName ldac, int hz)
+        : wcr_(dac | 0x3000), spi_(mosi, NC, sclk),
+          ld_(ldac, 0), mySpi_((SPI_TypeDef*)NULL)
+    {
+        if ( (mosi == PA_7) || (mosi == PB_5) )  mySpi_ = SPI1;
+        if ( (mosi == PB_15) || (mosi == PC_3) ) mySpi_ = SPI2;
+        if ( mosi == PC_12 )                     mySpi_ = SPI3;
+
+        // Set SPI format and bus frequency
+        spi_.format(16, 0);
+        spi_.frequency(hz);
+            
+        // timer prescaler is set same value of boud rate for SPI
+        uint16_t psc = (2 << ((mySpi_->CR1 >> 3) & 0x07)) - 1;
+        ss_ = new Tim4_ss(psc, 18, cs);
+        
+        // Set DAC to 0
+        WriteDac(0);
+        while (IsBusy()) {}
+    }
+
+    void DAC_MCP4922::Write(float value)
+    {
+        if (value < -1.0f) value = -1.0f;
+        if (value >  1.0f) value =  1.0f;
+
+        WriteDac((uint16_t)((value + 1.0f)*2047));
+    }
+
+    void DAC_MCP4922::Write(uint16_t value)
+    {
+        WriteDac((value > 4095) ? 4095 : value);
+    }
+        
+    void DAC_MCP4922::Ldac()
+    {
+        ld_.write(0);
+        ld_.write(0);   // ensure width of "L" pulse
+        ld_.write(1);
+    }
+
+    void DAC_MCP4922::WriteDac(uint16_t value)
+    {
+        ss_->SlaveSelect();
+        mySpi_->DR = value | wcr_;
+    }
+}
+
+
+
+
+