Mischa Megens / DACDMAfuncgenlib

Generate a sine wave on the Analog Output using DMA alone.

Dependencies:   DMAFuncGen MODDMA mbed

Files at this revision

API Documentation at this revision

Revision 0:697cc11ace92, committed 2013-12-29

Comitter:
Mischa
Date:
Sun Dec 29 01:13:41 2013 +0000
Commit message:
Demonstration program for the DMAFuncGen library

Changed in this revision

DMAFuncGen.lib Show annotated file Show diff for this revision Revisions of this file
MODDMA.lib 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
mbed.lib Show annotated file Show diff for this revision Revisions of this file 
diff -r 000000000000 -r 697cc11ace92 DMAFuncGen.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DMAFuncGen.lib	Sun Dec 29 01:13:41 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/Mischa/code/DMAFuncGen/#337ad0fe7734

diff -r 000000000000 -r 697cc11ace92 MODDMA.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MODDMA.lib	Sun Dec 29 01:13:41 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/AjK/code/MODDMA/#97a16bf2ff43

diff -r 000000000000 -r 697cc11ace92 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Dec 29 01:13:41 2013 +0000
@@ -0,0 +1,46 @@
+/*
+ * Demonstrates sending a buffer repeatedly to the DAC using DMA.
+ * Connect an oscilloscope to Mbed pin 18.
+ */
+
+#include "mbed.h"
+#include "DMAFuncGen.h"
+
+AnalogIn ain(p17);
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+DigitalOut led3(LED3);
+DigitalOut led4(LED4);
+
+MODDMA dma;
+DMAFuncGen fg(dma, MODDMA::Channel_0);
+
+int main() {
+    wait(0.5);
+   
+    // Create waveform.
+    fg.buffer_size=400;
+    fg.buffer = new uint32_t[fg.buffer_size];
+    const float PI = 3.1415927;
+    for (int i=0; i<fg.buffer_size; i++) {
+        int x = (511*sin(2*PI*i/fg.buffer_size)) +512;
+        fg.set(i,x << 6);
+    }
+    
+    fg.Connect();
+    fg.Setup();
+    fg.SetFrequency(0.5);
+    printf("Frequency: %f\r\n",fg.Frequency());
+    fg.Start();
+    
+    // Simple oscilloscope, using the LEDs -
+    // Connect pin 18 (DAC) to p17 (ADC) for it to work.
+    float z;
+    while (1){
+        z=ain.read();
+        led1 = (z > 0.2) ? 1 : 0;
+        led2 = (z > 0.4) ? 1 : 0;
+        led3 = (z > 0.6) ? 1 : 0;
+        led4 = (z > 0.8) ? 1 : 0;
+    }
+}

diff -r 000000000000 -r 697cc11ace92 mbed.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.lib	Sun Dec 29 01:13:41 2013 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/#dc225afb6914