Script voor het weergeven van 1 EMG signaal met behulp van een OLIMEX shield. Let hierbij goed op dat je de juiste pinnetjes op het OLIMEX shield verbonden hebt, in dit geval A0 als uitgang. Verder maken we gebruik van 3,3 Volt!

Dependencies:   HIDScope mbed

Fork of EMG by Tom Tom

Revision:
8:8a17f65622b4
Parent:
7:3396c3e33928
Child:
9:d33e7b175ad7
--- a/main.cpp	Wed Sep 10 04:59:25 2014 +0000
+++ b/main.cpp	Wed Sep 10 05:05:59 2014 +0000
@@ -4,8 +4,8 @@
 //Define objects
 AnalogIn    emg0(PTB1); //Analog input
 PwmOut      red(LED_RED); //PWM output
-Ticker timer;
-MODSERIAL pc(USBTX,USBRX,64,1024);
+Ticker log_timer;
+MODSERIAL pc(USBTX,USBRX);
 
 /** Looper function
 * functions used for Ticker and Timeout should be of type void <name>(void)
@@ -16,21 +16,22 @@
 * To make a variable global, define it under the includes.
 * variables that are changed in the interrupt routine (written to) should be made
 * 'volatile' to let the compiler know that those values may change outside the current context.
-* i.e.: "volatile float emg_value;" instead of "float emg_value"
+* i.e.: "volatile uint16_t emg_value;" instead of "uint16_t emg_value"
 * in the example below, the variable is not re-used in the main function, and is thus declared
 * local in the looper function only.
 **/
 void looper()
 {
     /*variable to store value in*/    
-    float emg_value;
+    uint16_t emg_value;
     /*put raw emg value both in red and in emg_value*/
-    red = emg_value = emg0.read();
-    /*send value to PC. use 6 digits after decimal sign*/
+    red = emg0.read();      // read float value (0..1 = 0..3.3V)
+    emg_value = emg0.read_u16(); // read direct ADC result (0..4096 = 0..3.3V)
+    /*send value to PC. Line below is used to prevent buffer overrun */
     if(pc.rxBufferGetSize(0)-pc.rxBufferGetCount() > 30)
-        pc.printf("%.6f\n",emg_value);
+        pc.printf("%u\n",emg_value);
     /**When not using the LED, the above could also have been done this way:
-    * pc.printf("%.6\n", emg0.read());
+    * pc.printf("%u\n", emg0.read_u16());
     */
 }
 
@@ -41,10 +42,10 @@
     /*set the period for the PWM to the red LED*/
     red.period_ms(2);
     /**Here you attach the 'void looper(void)' function to the Ticker object
-    * The looper() function will be called every 0.001 seconds.
+    * The looper() function will be called every 0.002 seconds.
     * Please mind that the parentheses after looper are omitted when using attach.
     */
-    timer.attach(looper, 0.005);
+    log_timer.attach(looper, 0.01);
     while(1) //Loop
     {
       /*Empty!*/