Diff: main.cpp

Revision:

0:1fe3a53ac109

Child:

1:e86fb31f7e95

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Dec 02 12:27:03 2020 +0000
@@ -0,0 +1,182 @@
+
+/* timing.cpp api verion 1.01 */
+/* wajw  21/03/18  */
+//V 1.02 mod to just do period measurement edh 24/03/18
+/* Prog to measure period of rotation of flywheel */
+
+
+/* Software uses Pin 9 as an interrupt to determine rotation period */
+/* A ticker is used to give a count of elapsed time */
+
+/* Interrupt occurs on +ve edge of TDC Pulse on pin10 */
+/* ISR Stores ticker count value as 'period', resets 'count' and sets flag */
+
+#include "mbed.h"
+#include "C12832_lcd.h"
+#define counts_per_min 600000 // .1ms clock = 600k pulses minute
+
+//advance degree and RPM data arrays 
+static int map[] = {5,5,6,10,15,15,21,25,27,34,38}; // advance angles in degrees BTDC
+static int rpm_range[] = {500,600,700,800,900,1000,1100,1200,1300,1400,1500}; //rpm range for which the advance angle should change 
+
+//Global Variables:
+
+volatile int  period = 0, count1 = 0; //this was changed to float to display the period more precisely
+
+volatile int pflag = 0, rpm = 0;
+
+int lag;
+int spark_advance; //to be used for the advance degree input
+
+C12832_LCD lcd;
+
+// Function Prototypes:
+
+void Tick1_isr (void);
+void TDC_isr (void);
+void Spark_on (void); // set the output Spark (p10) high
+void Spark_off (void); // set it low
+void Ignition(int);
+
+//custom function prototypes
+void advance_calculator(int);
+
+
+// Hardware Definitions:
+
+Ticker Tick; //Tick produces a periodic interrupt
+DigitalOut Spark(p10);  //Spark Output to Flywheel Board
+InterruptIn tdc(p9);    //Pulse from TDC Sensor on Flywheel Board
+
+Timeout StartSpark; //one-off interrupt to set spark o/p high
+Timeout EndSpark; // and this one sets spark low
+
+//Function Declarations:
+void Ignition(int lag)
+{
+    StartSpark.attach_us(&Spark_on, lag) ; // set time of Spark
+    EndSpark.attach_us(&Spark_off, lag + 200); //and duration of spark at 200usec
+}
+    
+void Spark_on()
+{
+    Spark = 1;
+}
+
+void Spark_off()
+{
+    Spark = 0;
+}
+
+
+void Tick1_isr()
+//Interrupt cause by Ticker
+//Increments count every 100usec
+{
+     count1++;   
+}
+
+void TDC_isr()
+ //Interrupt caused by +ve edge on TDC 
+ //Captured value = period 
+{
+    period = count1;    //Capture time since last TDC
+    count1 = 0;
+    pflag = 1;         // New value of period available
+}
+
+//custom functions declaration
+void advance_calculator(int rpm)
+{
+    if(rpm < rpm_range[0])
+    {
+        spark_advance = 360 - map[0];
+    }
+    else if(rpm >= rpm_range[0] && rpm < rpm_range[1])
+    {
+        spark_advance = 360 - map[0];
+    }
+    else if(rpm >= rpm_range[1] && rpm < rpm_range[2])
+    {
+        spark_advance = 360 - map[1];
+    }
+    else if(rpm >= rpm_range[2] && rpm < rpm_range[3])
+    {
+        spark_advance = 360 - map[2];
+    }
+    else if(rpm >= rpm_range[3] && rpm < rpm_range[4])
+    {
+        spark_advance = 360 - map[3];
+    }
+    else if(rpm >= rpm_range[4] && rpm < rpm_range[5])
+    {
+        spark_advance = 360 - map[4];
+    }
+    else if(rpm >= rpm_range[5] && rpm < rpm_range[6])
+    {
+        spark_advance = 360 - map[5];
+    }
+    else if(rpm >= rpm_range[6] && rpm < rpm_range[7])
+    {
+        spark_advance = 360 - map[6];
+    }
+    else if(rpm >= rpm_range[7] && rpm < rpm_range[8])
+    {
+        spark_advance = 360 - map[7];
+    }
+    else if(rpm >= rpm_range[8] && rpm < rpm_range[9])
+    {
+        spark_advance = 360 - map[8];
+    }
+    else if(rpm >= rpm_range[9] && rpm < rpm_range[10])
+    {
+        spark_advance = 360 - map[9];
+    }
+    else //this computes the angle for any speeds higher than 1500RPM (still same angle as 1500RPM)
+    {
+        spark_advance = 360 - map[10];
+    }
+}
+    
+ 
+int main()
+{ 
+
+//Produce regular clock tick for timing period:
+  Tick.attach_us(&Tick1_isr, 100);   //initializes the ticker with period of 100usec
+                                  //and attaches it to Tick1 ISR 
+
+   tdc.rise(&TDC_isr); // Generate Interrupt on each TDC pulse
+   
+   lcd.cls();
+   //advance_calculator(rpm); //called for the first time, since rpm is 0, 5 will be assigned to advance angle
+      
+    while(1) {
+       
+       
+        //spark_advance = 360 - 15; //360(TDC point) - advance angle = spark_advance
+       advance_calculator(rpm);
+       
+       if (pflag == 1) // new timing data?
+        {  
+            //lag = (period*100)*180/360; // Period is in units of 100usec
+            lag = (period*100)*spark_advance/360; // Period is in units of 100usec
+            Ignition(lag);
+            
+            //your code here to calculate rpm
+            rpm = (1/(period*100e-6))*60; //1 period = 1*100us(period counter incrments every 100us, this conversion is needed to get the Hz frequency
+            
+            lcd.locate(0,0);
+            lcd.printf("Period(T): %4.2d ms", period/10); // display captured data in ms to match the osciloscope reading 
+            lcd.locate(0,11);
+            lcd.printf("Speed(RPM): %4.2d ", rpm); // display captured data  
+            
+            //this is used to print the advance angle for troubleshooting purposes
+            lcd.locate(0,22);
+            lcd.printf("Advance(deg): %4.2d ", 360-spark_advance); // display captured data  
+            pflag = 0; //reset flag 
+        }
+        
+    }
+}
+