Revision 0:66f4c33802ab, committed 2017-03-09

Comitter:

jangelgm

Date:

Thu Mar 09 21:53:20 2017 +0000

Commit message:

DSP con filtro LP

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Mar 09 21:53:20 2017 +0000
@@ -0,0 +1,51 @@
+/* Program Example 11.2 DSP input and Output con inclusión de filtro LP
+*/
+#include "mbed.h"
+//mbed objects
+
+AnalogIn Ain(p15);
+
+AnalogOut Aout(p18);
+
+Ticker s20khz_tick;
+
+//function prototypes
+void s20khz_task(void);
+
+float LPF(float);
+
+//variables and data
+float data_in, data_out;
+
+//main program start here
+int main()
+{
+    s20khz_tick.attach_us(&s20khz_task,50); // attach task to 50us tick (20khz)
+}
+
+// function 20khz_task. Para realizar un muestreo a intervalos de 50us
+void s20khz_task(void)
+{
+    data_in=Ain;
+    data_out=LPF(data_in);  // Ejercicio 11.2
+    Aout=data_out;
+}
+
+float LPF(float LPF_in)
+{
+    float a[4]= {1,2.6235518066,-2.3146825811,0.6855359773};
+    float b[4]= {0.0006993496,0.0020980489,0.0020980489,0.0006993496};
+    static float LPF_out;
+    static float x[4], y[4];
+    x[3] = x[2];
+    x[2] = x[1];
+    x[1] = x[0]; // move x values by one sample
+    y[3] = y[2];
+    y[2] = y[1];
+    y[1] = y[0]; // move y values by one sample
+    x[0] = LPF_in; // new value for x[0]
+    y[0] = (b[0]*x[0]) + (b[1]*x[1]) + (b[2]*x[2]) + (b[3]*x[3])
+           + (a[1]*y[1]) + (a[2]*y[2]) + (a[3]*y[3]);
+    LPF_out = y[0];
+    return LPF_out; // output filtered value
+}
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu Mar 09 21:53:20 2017 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/6c34061e7c34
\ No newline at end of file