Diff: main.cpp

Revision:

0:bdf668d4c05b

Child:

1:b81dc534e7d7

diff -r 000000000000 -r bdf668d4c05b main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Nov 02 02:15:49 2018 +0000
@@ -0,0 +1,70 @@
+#include "mbed.h"
+#include "math.h"
+/**********************
+ *      MCP4922
+ **********************/
+
+///SPI Interface
+SPI MCP4922_SPI(D11,D12,D13);//MOSI ,MISO ,SCK
+DigitalOut MCP4922_CS(D7);//CS
+
+
+
+//Digital Output
+DigitalOut MCP4922_LDAC(D4);
+DigitalOut MCP4922_SHDN(D6);
+void volt_out(double volt)
+{
+
+    uint16_t temp=((uint16_t)(volt*4096/3.33))&0x0fff;
+    uint16_t MCP4922_Sent_Data = 0;
+    MCP4922_Sent_Data = 0x3000|temp;
+    //MCP4922_Sent_Data = 0x3fff;
+    MCP4922_CS = 0;
+
+
+    //sent data buffer to mcp4922
+    MCP4922_SPI.write(MCP4922_Sent_Data);
+
+    //set CS to High to End MCP4922 SPI Interface
+    MCP4922_CS = 1;
+
+    //set LDAC to LOW to Load data to output
+    MCP4922_LDAC = 0 ;
+
+    //wait at least 100ns = 0.1 microsec ..... So set at 1 microsec
+    wait_us(1);
+
+    //set LDAC to High to prepare next output
+    MCP4922_LDAC = 1 ;
+}
+int main()
+{
+    /******************************
+     *****      setup       *******
+     ******************************/
+
+    /////////setup SPI//////////
+    //set CS High
+    MCP4922_CS=1;
+
+    //set SPI mode [1,1]=> mode 3 @16bit
+    MCP4922_SPI.format(16,3);
+
+    //set SPI Frequency @20MHz
+    MCP4922_SPI.frequency(20000000);
+
+    //set Load DAC High (inactive)
+    MCP4922_LDAC = 1;
+
+    //set shutdown DAC High (inactive)
+    MCP4922_SHDN = 1;
+
+    //loop
+    while(1) {
+        for(double x=0; x<2*3.141592; x+=0.00001) {
+            volt_out((sin(x)+1.00)*3.33/2.00);
+        }
+
+    }
+}