added frequency display

frequency.c

@@ -0,0 +1,43 @@
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "driverlib/sysctl.h"
+#include "driverlib/gpio.h"
+#include "driverlib/timer.h"
+#include "driverlib/pin_map.h"
+#include "inc/tm4c1294ncpdt.h"
+#include "driverlib/interrupt.h"
+#include "inc/hw_types.h"
+#include "inc/hw_memmap.h"
+
+#include "frequency.h"
+
+
+void start_frequency_scan() {
+    // config GPIO PD0 as timer input T0CCP0 at BoosterPack Connector #1 pin 14
+    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
+    GPIOPinTypeTimer(GPIO_PORTD_BASE, GPIO_PIN_0);
+    GPIOPinConfigure(GPIO_PD0_T0CCP0);
+    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
+    TimerDisable(TIMER0_BASE, TIMER_BOTH);
+    TimerConfigure(TIMER0_BASE, TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_CAP_TIME_UP);
+    TimerControlEvent(TIMER0_BASE, TIMER_A, TIMER_EVENT_POS_EDGE);
+    // use maximum load value
+    TimerLoadSet(TIMER0_BASE, TIMER_A, 0xffff);
+    // use maximum prescale value
+    TimerPrescaleSet(TIMER0_BASE, TIMER_A, 0xff);
+    TimerIntEnable(TIMER0_BASE, TIMER_CAPA_EVENT);
+    TimerEnable(TIMER0_BASE, TIMER_A);
+}
+
+uint32_t previous;
+void capture_handler() {
+    TimerIntClear(TIMER0_BASE, TIMER_CAPA_EVENT);
+
+    uint32_t current = TimerValueGet(TIMER0_BASE, TIMER_A);
+
+    uint32_t delta = current - previous;
+    gPeriod = delta;
+
+    previous = current;
+}

frequency.h

@@ -0,0 +1,6 @@
+#ifndef FREQUENCY_C
+#define FREQUENCY_C
+void start_frequency_scan(void);
+
+uint32_t gPeriod;
+#endif

main.c

@@ -31,6 +31,7 @@
 #include "driverlib/pin_map.h"
 #include "sampling.h"
 #include "buttons.h"
+#include "frequency.h"
 #include "kiss_fft.h"
 #include "_kiss_fft_guts.h"
 
@@ -149,6 +150,7 @@ int main(void)
     start_sampler();
     ButtonInit();
     start_cputimer();
+    start_frequency_scan();
 
     Crystalfontz128x128_Init(); // Initialize the LCD display driver
     Crystalfontz128x128_SetOrientation(LCD_ORIENTATION_UP); // set screen orientation
@@ -318,6 +320,10 @@ void display_waveform(UArg arg1, UArg arg2)
         GrContextForegroundSet(&sContext, ClrWheat);
 
         snprintf(str, sizeof(str), "CPU Load %.1f%%", usage_percent);
+        GrStringDraw(&sContext, str, /*length*/ -1, /*x*/ 0, /*y*/ HEIGHT - 20, /*opaque*/ false);
+
+        float frequency = (float) gSystemClock / (float) gPeriod;
+        snprintf(str, sizeof(str), "f = %.1fhz", frequency);
         GrStringDraw(&sContext, str, /*length*/ -1, /*x*/ 0, /*y*/ HEIGHT - 10, /*opaque*/ false);
 
 

rtos.cfg

@@ -535,7 +535,7 @@ var driversConfig = xdc.useModule('ti.drivers.Config');
  *      Use TI-RTOS drivers library for debugging with asserts and logs enabled.
  */
 driversConfig.libType = driversConfig.LibType_NonInstrumented;
-Clock.timerId = 0;
+Clock.timerId = 2;
 TimestampProvider.useClockTimer = true;
 var m3Hwi0Params = new m3Hwi.Params();
 m3Hwi0Params.instance.name = "m3Hwi0";
@@ -597,3 +597,7 @@ Program.global.options_sem = Semaphore.create(1, semaphore4Params);
 var gateHwi0Params = new GateHwi.Params();
 gateHwi0Params.instance.name = "gateHwiDMA";
 Program.global.gateHwi0 = GateHwi.create(gateHwi0Params);
+var m3Hwi1Params = new m3Hwi.Params();
+m3Hwi1Params.instance.name = "m3Hwi1";
+m3Hwi1Params.priority = 4;
+Program.global.m3Hwi1 = m3Hwi.create(35, "&capture_handler", m3Hwi1Params);