Diff: main.cpp

Revision:

0:d81660bd4a9b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Apr 21 04:34:02 2016 +0000
@@ -0,0 +1,81 @@
+#include "mbed.h"
+Serial pc(USBTX, USBRX); // Initlize UART on USB port of KL25Z with default Baud 9600
+AnalogOut aout(PTE30); // The waveform is created on this pin
+void showhelp()
+{
+    pc.printf("\r\n"); // print Command list from new line on UART Terminal
+    pc.printf("**** Command List ****\r\n"); // print Command list on UART Terminal
+    pc.printf("h -> Help\r\n");
+    pc.printf("s -> Generate Sine wave\r\n");
+    pc.printf("t -> Generate Triangular Wave\r\n");
+    pc.printf("i -> Increase Amplitude\r\n");
+    pc.printf("d -> Decrease Amplitude\r\n");
+
+}
+int main()
+{
+    const double pi = 3.14;
+    const double offset = 65535/2;
+    double rads = 0.0;
+    uint16_t sample = 0;
+    float amplitude = 0.0f;
+    char rxbyte;
+    int wavetype = 0;
+    // pc.baud(115200); // uncomment this line and update baudrate to cahnge baud rate from 9600 default
+    pc.printf("\r\n"); // print startup message from new line on UART Terminal
+    pc.printf("Experiment - 13\r\n"); // print startup message on UART Terminal
+    pc.printf("DAC Waveform Generator\r\n"); // print startup message on UART Terminal
+    showhelp();
+    wait(3.0); // wait 3 second to show startup message
+    while(1) {
+        if (pc.readable()) { // If pc is readable
+            rxbyte = pc.getc();
+            if(rxbyte == 's') {
+                pc.printf("SINE WAVE\r\n");
+                wavetype = 0;
+            } else if(rxbyte == 't') {
+                pc.printf("TRIANGULAR WAVE\r\n");
+                wavetype = 1;
+            } else if(rxbyte == 'i') {
+                pc.printf("AMPLITUDE INCREASED\r\n");
+                amplitude+=0.1f;
+            } else if(rxbyte == 'd') {
+                pc.printf("AMPLITUDE INCREASED\r\n");
+                amplitude-=0.1f;
+            } else if(rxbyte == 'h') {
+                showhelp();
+            } else  {
+                pc.printf("Error: Invalid command type 'h' for help...\r\n");
+            }
+            rxbyte = 0x00;
+            if(amplitude>1.0f) {
+                amplitude = 1.0f;
+                pc.printf("Amplitude Max limit reached...\r\n");
+            } else if(amplitude<0.0f) {
+                amplitude = 0.0f;
+                pc.printf("Amplitude Min limit reached...\r\n");
+            }
+        }
+
+        if(wavetype == 0) {
+            // sinewave output
+            for (int i = 0; i < 360; i++) {
+                rads = (pi * i) / 180.0f;
+                sample = (uint16_t)(amplitude * (offset * (cos(rads + pi))) + offset);
+                aout.write_u16(sample);
+            }
+        }
+
+        if(wavetype == 1) {
+            // triwave output
+            for (float i = 0.5f - (amplitude/2); i < 0.5f + (amplitude/2); i += 0.01f) {
+                aout = i;
+                wait(0.0003f);
+            }
+            for (float i = 0.5f + (amplitude/2); i > 0.5f - (amplitude/2); i -= 0.01f) {
+                aout = i;
+                wait(0.0003f);
+            }
+        }
+    }
+}
\ No newline at end of file