Diff: frequency_detector.cpp

Revision:

0:4fb921928934

Child:

1:9fa7cc80f1a7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/frequency_detector.cpp	Fri Oct 04 21:09:15 2019 +0000
@@ -0,0 +1,128 @@
+/**----------------------------------------------------------------------------
+ *
+ *            \file frequency_detector.cpp
+--                                                                           --
+--              ECEN 5803 Mastering Embedded System Architecture             --
+--                  Project 1 Module 4                                       --
+--                Microcontroller Firmware                                   --
+--                      frequency_detector.cpp                                           --
+--                                                                           --
+-------------------------------------------------------------------------------
+--
+--  Designed for:  University of Colorado at Boulder
+--                
+--                
+--  Designed by:  Tim Scherr
+--  Revised by:  Naved Maududi and Bryan Cisneros 
+-- 
+-- Version: 2.1
+-- Date of current revision:  2017-09-25   
+-- Target Microcontroller: Freescale MKL25ZVMT4 
+-- Tools used:  ARM mbed compiler
+--              ARM mbed SDK
+--              Freescale FRDM-KL25Z Freedom Board
+--               
+--               
+   Functional Description:  
+   This file contains code that takes in quasi-sine wave ADC inputs from the flow meter
+     From the ADC inputs, it calculates the frequency of that sine wave. The frequency is 
+     important in determining the flow rate and velocity for the flowmeter that are outputed
+     to the display. 
+-- 
+--      Copyright (c) 2015 Tim Scherr  All rights reserved.
+*/
+
+
+#include "shared.h" 
+
+#ifdef __cplusplus 
+extern "C" {
+#endif
+/**********************/   
+/*   Definitions     */
+/**********************/
+
+extern uint16_t zero_detect_counter = 0; // initialize the value to zero
+extern UCHAR sample_count =0; // intialize sample count to zero
+extern uint32_t frequency_buffer[10] = {0,0,0,0,0,0,0,0,0,0};
+extern UCHAR frequency_buffer_count = 0;
+extern UCHAR reset_counter_flag = 0;
+extern UCHAR current_bool_value =1; // trigger for zero detection within the code
+extern UCHAR last_bool_value = 1; // trigger for zero detection within the code
+
+    
+#ifdef __cplusplus
+}
+#endif
+
+// read in ADC from the professor and store it within this function (ADC() will store a value within 
+//will write code to keep going through this buffer, need to be able to store value to this function fast enough
+//uint16_t ADC_buffer;
+//UCHAR size_ADC_array = 10;
+void frequency_detect(void)
+{  int32_t i;
+    
+   if(reset_counter_flag==1)
+         {
+       zero_detect_counter = 0; // reset the value of counter each 800us has passed, want to attain the moving average(fed from timer0.cpp)
+         reset_counter_flag=0; // set reset flag back to 0
+    }
+
+      if(ADC_vortex_frequency_input<=0) 
+          {
+             current_bool_value =0; // negative values set to 0
+          }
+             else
+             {
+             current_bool_value =1; // positive value set to 1
+       }
+             
+        if((current_bool_value != last_bool_value))
+        {
+   last_bool_value = current_bool_value;
+   zero_detect_counter = zero_detect_counter+1;
+            
+     if ((frequency_buffer_count<10) && (zero_detect_counter>=2))
+     {
+         frequency_buffer[frequency_buffer_count]  = ((zero_detect_counter-1)/((sample_count)*(SAMPLES_SECOND)))/2;
+             frequency_buffer_count = frequency_buffer_count+1;
+     }
+    else 
+        {
+            frequency_buffer_count = 1;
+    }
+   
+    }
+    
+  if((zero_detect_counter == 0) & (reset_counter_flag == 0))
+    {
+      sample_count = 1;
+  }
+    else if(zero_detect_counter>0)
+    {
+    sample_count++; // only evaluated at the beginning of code during resets
+  }
+    else {
+        sample_count = 1; // needed to not divide by zero
+    }
+
+        uint16_t sum_frequency_buffer= 0;
+
+        for(i = 1; i < 10; ++i)
+    {
+        sum_frequency_buffer += frequency_buffer[i];
+    }
+        
+        if ((sum_frequency_buffer/9)>3000)
+        {
+            freq_value = 0;
+        }
+    else
+        {
+           freq_value = sum_frequency_buffer/9;
+        }
+
+}
+
+
+