hcsr04: fixes driver and addresses issue #207

Signed-off-by: Rafael Neri <rafael.neri@gmail.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

examples/c++/CMakeLists.txt

@@ -18,7 +18,7 @@ add_executable (nrf24l01-transmitter-example nrf24l01-transmitter.cxx)
 add_executable (nrf24l01-receiver-example nrf24l01-receiver.cxx)
 add_executable (nrf24l01-broadcast-example nrf24l01-broadcast.cxx)
 add_executable (es08a-example es08a.cxx)
-add_executable (son-hcsr04-example hcsr04.cxx)
+add_executable (hcsr04-example hcsr04.cxx)
 add_executable (ssd1308-oled-example ssd1308-oled.cxx)
 add_executable (ssd1327-oled-example ssd1327-oled.cxx)
 add_executable (max44000-example max44000.cxx)
@@ -269,7 +269,7 @@ target_link_libraries (nrf24l01-transmitter-example nrf24l01 ${CMAKE_THREAD_LIBS
 target_link_libraries (nrf24l01-receiver-example nrf24l01 ${CMAKE_THREAD_LIBS_INIT})
 target_link_libraries (nrf24l01-broadcast-example nrf24l01 ${CMAKE_THREAD_LIBS_INIT})
 target_link_libraries (es08a-example servo ${CMAKE_THREAD_LIBS_INIT})
-target_link_libraries (son-hcsr04-example hcsr04 ${CMAKE_THREAD_LIBS_INIT})
+target_link_libraries (hcsr04-example hcsr04 ${CMAKE_THREAD_LIBS_INIT})
 target_link_libraries (ssd1308-oled-example i2clcd ${CMAKE_THREAD_LIBS_INIT})
 target_link_libraries (ssd1327-oled-example i2clcd ${CMAKE_THREAD_LIBS_INIT})
 target_link_libraries (max44000-example max44000 ${CMAKE_THREAD_LIBS_INIT})

examples/c++/hcsr04.cxx

@@ -50,11 +50,17 @@ interrupt (void * args) {
 int
 main(int argc, char **argv)
 {
-    sonar = new upm::HCSR04(5, 7, &interrupt);
+    sonar = new upm::HCSR04(5, 6, &interrupt);
     signal(SIGINT, sig_handler);
 
-    printf ("width = %d\n", sonar->getDistance());
-    std::cout << "exiting application" << std::endl;
+    sleep(1);
+
+    for(;;){
+        std::cout << "get distance" << std::endl;
+        double distance = sonar->getDistance(CM);
+        std::cout << "distance " << distance << std::endl;
+        sleep(5);
+    }
 
     delete sonar;
 

src/hcsr04/hcsr04.cxx

@@ -1,6 +1,7 @@
 /*
  * Author: Yevgeniy Kiveisha <yevgeniy.kiveisha@intel.com>
- * Copyright (c) 2014 Intel Corporation.
+ * Author: Rafael Neri <rafael.neri@gmail.com>
+ * Copyright (c) 2014-2015 Intel Corporation.
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -42,13 +43,17 @@ HCSR04::HCSR04 (uint8_t triggerPin, uint8_t echoPin, void (*fptr)(void *)) {
     mraa_result_t error  = MRAA_SUCCESS;
     m_name              = "HCSR04";
 
-    m_pwmTriggerCtx     = mraa_pwm_init (triggerPin);
-    if (m_pwmTriggerCtx == NULL) {
-        std::cout << "PWM context is NULL" << std::endl;
+    mraa_init();
+
+    m_triggerPinCtx     = mraa_gpio_init (triggerPin);
+    if (m_triggerPinCtx == NULL) {
+        fprintf (stderr, "Are you sure that pin%d you requested is valid on your platform?", triggerPin);
         exit (1);
     }
 
-    mraa_init();
+    mraa_gpio_dir(m_triggerPinCtx, MRAA_GPIO_OUT);
+    mraa_gpio_write (m_triggerPinCtx, 0);
+
     m_echoPinCtx = mraa_gpio_init(echoPin);
     if (m_echoPinCtx == NULL) {
         fprintf (stderr, "Are you sure that pin%d you requested is valid on your platform?", echoPin);
@@ -62,24 +67,27 @@ HCSR04::HCSR04 (uint8_t triggerPin, uint8_t echoPin, void (*fptr)(void *)) {
 HCSR04::~HCSR04 () {
     mraa_result_t error = MRAA_SUCCESS;
 
-    mraa_pwm_close (m_pwmTriggerCtx);
+    error = mraa_gpio_close (m_triggerPinCtx);
+    if (error != MRAA_SUCCESS) {
+        mraa_result_print (error);
+    }
+
     error = mraa_gpio_close (m_echoPinCtx);
     if (error != MRAA_SUCCESS) {
         mraa_result_print (error);
     }
 }
 
-int
-HCSR04::getDistance () {
-    mraa_pwm_enable (m_pwmTriggerCtx, 1);
-    mraa_pwm_period_us (m_pwmTriggerCtx, MAX_PERIOD);
-    mraa_pwm_pulsewidth_us (m_pwmTriggerCtx, TRIGGER_PULSE);
-    mraa_pwm_enable (m_pwmTriggerCtx, 0);
+double
+HCSR04::timing() {
+    mraa_gpio_write (m_triggerPinCtx, 1);
+    usleep(10);
+    mraa_gpio_write (m_triggerPinCtx, 0);
 
     m_doWork = 0;
     m_InterruptCounter = 0;
     while (!m_doWork) {
-        sleep (1);
+        usleep (5);
     }
 
     return m_FallingTimeStamp - m_RisingTimeStamp;
@@ -98,3 +106,15 @@ HCSR04::ackEdgeDetected () {
         m_RisingTimeStamp = 1000000 * timer.tv_sec + timer.tv_usec;
     }
 }
+
+double
+HCSR04::getDistance(int sys)
+{
+    double _timing = timing();
+    if (sys)
+    {
+        return (_timing/2) / 29.1;
+    } else {
+        return (_timing/2) / 74.1;
+    }
+}

src/hcsr04/hcsr04.h

@@ -1,6 +1,7 @@
- /*
+/*
  * Author: Yevgeniy Kiveisha <yevgeniy.kiveisha@intel.com>
- * Copyright (c) 2014 Intel Corporation.
+ * Author: Rafael Neri <rafael.neri@gmail.com>
+ * Copyright (c) 2014-2015 Intel Corporation.
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -33,11 +34,8 @@
 #include "../IsrCallback.h"
 #endif
 
-#define HIGH                   1
-#define LOW                    0
-
-#define MAX_PERIOD             7968
-#define TRIGGER_PULSE          10
+#define CM 1
+#define INC 0
 
 namespace upm {
 /**
@@ -62,9 +60,6 @@ namespace upm {
  */
 class HCSR04 {
     public:
-#if defined(SWIGJAVA) || defined(JAVACALLBACK)
-        HCSR04 (uint8_t triggerPin, uint8_t echoPin, IsrCallback *cb);
-#else 
         /**
          * Instantiates an HCSR04 object
          *
@@ -73,6 +68,9 @@ class HCSR04 {
          * @param fptr Function pointer to handle rising-edge and
          * falling-edge interrupts
          */
+#if defined(SWIGJAVA) || defined(JAVACALLBACK)
+        HCSR04 (uint8_t triggerPin, uint8_t echoPin, IsrCallback *cb);
+#else
         HCSR04 (uint8_t triggerPin, uint8_t echoPin, void (*fptr)(void *));
 #endif
         /**
@@ -83,7 +81,7 @@ class HCSR04 {
         /**
          * Gets the distance from the sensor
          */
-        int getDistance ();
+        double getDistance (int sys);
 
         /**
          * On each interrupt, this function detects if the interrupt
@@ -106,10 +104,10 @@ class HCSR04 {
 #if defined(SWIGJAVA) || defined(JAVACALLBACK)
         HCSR04 (uint8_t triggerPin, uint8_t echoPin, void (*fptr)(void *));
 #endif
-        mraa_pwm_context     m_pwmTriggerCtx;
-        mraa_gpio_context    m_echoPinCtx;
+        double timing();
+        mraa_gpio_context   m_triggerPinCtx;
+        mraa_gpio_context   m_echoPinCtx;
 
-        uint8_t m_waitEcho;
         long    m_RisingTimeStamp;
         long    m_FallingTimeStamp;
         uint8_t m_InterruptCounter;