[TEST] Count ticks with PortIn

main.cpp

@@ -1,122 +1,64 @@
-/*
- * Copyright (c) 2017-2020 Arm Limited and affiliates.
- * SPDX-License-Identifier: Apache-2.0
- */
-
 #include "mbed.h"
 
-#include "LPC17xx.h"
+PortIn port(Port0, 0x0000003F);
 
-static const unsigned FRAME_LENGTH = 20;
-static const uint32_t SIGNAL_BIT = 0x10000000U; // don't use 0x80000000U as it is `osFlagsError`
+volatile bool stateClock = true;
+volatile bool stateData = true;
 
-volatile unsigned int _countClock;
-volatile unsigned int _countData;
+volatile int clockTicks = 0;
+volatile int dataTicks = 0;
 
-volatile bool isTransmittingFrame = false;
-volatile bool isStartPulse = false; // pulse high-low-high on DATA while DLCK is high
-volatile bool clockState = true;
-volatile bool dataState = true;
-volatile unsigned int index = FRAME_LENGTH;
-volatile uint32_t buffer = SIGNAL_BIT;
-volatile unsigned int frames = 0;
+Thread thread;
 
-extern "C" void EINT3_IRQHandler(void)
+void worker()
 {
-    // Clear the interrupt.
-    LPC_GPIOINT->IO0IntClr = ~((uint32_t) 0);
+    int value;
 
-    if ((LPC_GPIOINT->IO0IntStatR & (1 << 0)) == (1 << 0))
+    while (true)
     {
-        _countClock++;
+        value = port.read();
 
-        clockState = true;
-
-        if (isTransmittingFrame)
+        if ((value & 0x00000001) == 1)
         {
-            buffer |= (dataState ? 1 : 0) << --index;
-
-            if (index == 0)
+            if (!stateClock)
             {
-                isTransmittingFrame = false;
-                frames++;
-                // thread.flags_set(buffer);
-                // sem.release();
-                index = FRAME_LENGTH;
+                clockTicks++;
+                stateClock = true;
             }
         }
-        else if (isStartPulse)
+        else
         {
-            // invalidate, we are amid a frame transmission (which is not being accounted)
-            isStartPulse = false;
+            if (stateClock)
+            {
+                stateClock = false;
+            }
         }
-    }
-    else if ((LPC_GPIOINT->IO0IntStatF & (1 << 0)) == (1 << 0))
-    {
-        clockState = false;
-    }
-    else if ((LPC_GPIOINT->IO0IntStatR & (1 << 1)) == (1 << 1))
-    {
-        _countData++;
 
-        dataState = true;
-
-        if (!isTransmittingFrame && isStartPulse && clockState)
+        if ((value & 0x00000002) == 1)
         {
-            isStartPulse = false;
-            isTransmittingFrame = true;
-            buffer = SIGNAL_BIT;
+            if (!stateData)
+            {
+                dataTicks++;
+                stateData = true;
+            }
         }
-    }
-    else if ((LPC_GPIOINT->IO0IntStatF & (1 << 1)) == (1 << 1))
-    {
-        dataState = false;
-
-        if (!isTransmittingFrame && clockState)
+        else
         {
-            isStartPulse = true;
+            if (stateData)
+            {
+                stateData = false;
+            }
         }
     }
 }
 
-class Counter
-{
-public:
-    Counter(unsigned int clockPin, unsigned int dataPin)
-    {
-        __disable_irq();
-
-        NVIC_DisableIRQ(EINT3_IRQn);
-
-        // Power up GPIO.
-        // LPC_SC->PCONP |= (1 << 15);
-
-        // GPIO P0.0 and P0.1 as input.
-        LPC_PINCON->PINSEL0 &= ~((1 << 3) | (1 << 2) | (1 << 1) | (1 << 0));
-        // LPC_PINCON->PINMODE1 &= ~(0x3 << 0);
-        // LPC_PINCON->PINMODE1 |= (0x3 << 0);
-        LPC_GPIO0->FIODIR &= ~((1 << 1) | (1 << 0));
-
-        LPC_GPIOINT->IO0IntEnR |= ((1 << 1) | (1 << 0));
-        LPC_GPIOINT->IO0IntEnF |= ((1 << 1) | (1 << 0));
-
-        LPC_SC->EXTINT = 1;
-
-        NVIC_EnableIRQ(EINT3_IRQn);
-
-        __enable_irq();
-    }
-};
-
 int main()
 {
-    Counter counter(9, 10);
+    thread.start(callback(&worker));
 
     while (true)
     {
-        printf("Count so far: cticks=%d dticks=%d frames=%d data=0x%08X\n", _countClock, _countData, frames, buffer);
-        ThisThread::sleep_for(2000);
+        printf("cticks = %d, dticks = %d\n", clockTicks, dataTicks);
+        ThisThread::sleep_for(1000);
     }
-
-    return 0;
 }