yasuyuki onodera
MCP4726 sample
Dependencies: AQM0802 MCP4726 mbed
See http://developer.mbed.org/users/yasuyuki/notebook/MCP4726/
Revision 0:676aa4ff0765, committed 2014-10-15
- Comitter:
- yasuyuki
- Date:
- Wed Oct 15 14:45:19 2014 +0000
- Commit message:
- first release
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/AQM0802.lib Wed Oct 15 14:45:19 2014 +0000 @@ -0,0 +1,1 @@ +https://mbed.org/users/yasuyuki/code/AQM0802/#6fa303916aa8
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MCP4726.lib Wed Oct 15 14:45:19 2014 +0000 @@ -0,0 +1,1 @@ +http://developer.mbed.org/users/yasuyuki/code/MCP4726/#f0980556dfc0
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Wed Oct 15 14:45:19 2014 +0000
@@ -0,0 +1,84 @@
+//**********************
+// DDS with DAC 12bits
+// MCP4726 sample for mbed
+//
+// output
+// (1)sin wave with DDS, 1Hz-1KHz
+//
+// (C)Copyright 2014 All rights reserved by Y.Onodera
+// http://einstlab.web.fc2.com
+//**********************
+#include "mbed.h"
+#include "AQM0802.h"
+#include "MCP4726.h"
+
+#define PI 3.14159265
+// sampling frequency for DDS
+// 400KHz
+#define S 8400
+// 1MHz
+//#define S 12000
+
+#if defined(TARGET_LPC1768)
+I2C i2c(p28,p27);
+#endif
+// for TG-LPC11U35-501
+#if defined(TARGET_LPC11U35_501)
+I2C i2c(P0_5,P0_4);
+#endif
+// for Nucleo
+#if defined(TARGET_NUCLEO_F401RE)
+I2C i2c(D14,D15);
+#endif
+AQM0802 lcd(i2c);
+MCP4726 mcp4726(i2c);
+Ticker dds;
+
+unsigned short f;
+unsigned short sin_table[360];
+
+
+void sampling()
+{
+ static int t=0;
+ unsigned short x;
+ float a;
+
+ x=360*modff((float)f*t/S,&a);
+ x = sin_table[x];
+ if(++t>=S)t=0;
+
+ // D/A
+ mcp4726.put(x);
+}
+
+
+int main() {
+
+ char msg[10];
+ int i;
+
+ // to make 12bits sine table
+ for(i=0;i<360;i++){
+ sin_table[i]=0x7ff*sin(2*PI/360*i)+0x7ff;
+ }
+
+ // start signal with sampling
+ dds.attach_us(&sampling,1000000/S); // for us
+
+ while(1){
+ // Set f, test signal
+ // 10-1KHz
+ for(f=10;f<=1000;f+=10){
+ sprintf(msg, "%5d Hz", f );
+ __disable_irq();
+ lcd.locate(0,0);
+ lcd.print(msg);
+ __enable_irq();
+ wait(1);
+ }
+ }
+
+}
+
+
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Wed Oct 15 14:45:19 2014 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/552587b429a1 \ No newline at end of file