Memory handling with MRAA device contexts

RF24.h

@@ -114,6 +114,9 @@ public:
   
   RF24(uint8_t _cepin, uint8_t _cspin, uint32_t spispeed );
   //#endif
+
+  virtual ~RF24() {};
+
   /**
    * Begin operation of the chip
    * 

arch/MRAA/RF24_arch_config.h

@@ -4,7 +4,8 @@
   #include "mraa.h"
   #include "spi.h"
   #include "gpio.h"
-  #include "compatibility.h"
+  //#include "compatibility.h"
+  #include <UtilTime.h>
   #include <stdint.h>
   #include <stdio.h>
   #include <time.h>
@@ -30,6 +31,7 @@
   //typedef uint16_t prog_uint16_t;
   #define PSTR(x) (x)
   #define printf_P printf
+  #define sprintf_P sprintf
   #define strlen_P strlen
   #define PROGMEM
   #define PRIPSTR "%s"
@@ -44,9 +46,9 @@
   #define digitalWrite(pin, value) gpio.write(pin, value)
   #define digitalRead(pin) GPIO::read(pin)
   #define pinMode(pin, direction) gpio.open(pin, direction)
-  #define delay(milisec) __msleep(milisec)
-  #define delayMicroseconds(usec) __usleep(usec)
-  #define millis() __millis()
+  //#define delay(milisec) __msleep(milisec)
+  //#define delayMicroseconds(usec) __usleep(usec)
+  //#define millis() __millis()
   
   #define INPUT mraa::DIR_IN
   #define OUTPUT mraa::DIR_OUT  

arch/MRAA/gpio.cpp

@@ -6,9 +6,17 @@
 #include "gpio.h"
 
 GPIO::GPIO() {
+	// Prophet: basic members initialization
+	gpio_ce_pin = -1;
+	gpio_cs_pin = -1;
+	gpio_0 = NULL;
+	gpio_1 = NULL;
 }
 
 GPIO::~GPIO() {
+	// Prophet: this should free memory, and unexport pins when RF24 and/or GPIO gets deleted or goes out of scope
+	this->close(gpio_ce_pin);
+	this->close(gpio_cs_pin);
 }
 
 void GPIO::begin(uint8_t ce_pin, uint8_t cs_pin)
@@ -16,9 +24,10 @@ void GPIO::begin(uint8_t ce_pin, uint8_t cs_pin)
 	gpio_ce_pin = ce_pin;
 	gpio_cs_pin = cs_pin;
 	
-	gpio_0 = new mraa::Gpio(ce_pin,0);
-	gpio_1 = new mraa::Gpio(cs_pin,0);
-	
+	// Prophet: owner can be set here, because we use our pins exclusively, and are making mraa:Gpio context persistent
+	// so pins will be unexported only if close is called, or on destruction
+	gpio_0 = new mraa::Gpio(ce_pin/*,0*/);
+	gpio_1 = new mraa::Gpio(cs_pin/*,0*/);
 }
 void GPIO::open(int port, int DDR)
 {		
@@ -36,8 +45,20 @@ void GPIO::open(int port, int DDR)
 
 void GPIO::close(int port)
 {	
+	// Prophet: using same theme of working with port numbers as with GPIO::open,
+	// checking for mraa::Gpio context existence to be sure, that GPIO::begin was called
+	if(port == gpio_ce_pin)
+	{
+		if (gpio_0 != NULL)	{
 			delete gpio_0;
+		}
+	}
+
+	if(port == gpio_cs_pin) {
+		if (gpio_1 != NULL)	{
 			delete gpio_1;
+		}
+	}
 }
 
 int GPIO::read(int port)

arch/MRAA/gpio.h

@@ -3,8 +3,8 @@
  * 
  */
 
-#ifndef H
-#define	H
+#ifndef RF24_ARCH_GPIO_H
+#define	RF24_ARCH_GPIO_H
 
 #include <cstdio>
 #include <stdio.h>
@@ -17,6 +17,7 @@ public:
 	/* Constants */
 		
 	GPIO();
+	virtual ~GPIO();
 	
 	/**
 	 * Sets up GPIO on the CE & CS pins
@@ -49,8 +50,6 @@ public:
 	*/	
 	void write(int port,int value);	
 
-	virtual ~GPIO();
-	
 private:
 	int gpio_ce_pin; /** ce_pin value of the RF24 device **/
 	int gpio_cs_pin; /** cs_pin value of the RF24 device **/
@@ -58,5 +57,5 @@ private:
 	mraa::Gpio* gpio_1; /** gpio object for cs_pin **/
 };
 
-#endif	/* H */
+#endif	/* RF24_ARCH_GPIO_H */
 

arch/MRAA/spi.cpp

@@ -3,20 +3,31 @@
 #include "spi.h"
 
 SPI::SPI() {
-
+	mspi = NULL;
 }
 
 
-void SPI::begin( ) {	
+void SPI::begin(void) {
 
 	mspi = new mraa::Spi(0);
 
 	mspi->mode(mraa::SPI_MODE0);
 	mspi->bitPerWord(8);
-	mspi->frequency(8000000);
+	mspi->frequency(4000000);
+}
+
+// Prophet: this is only a suggestion, but can be useful for devices with multiple SPI ports
+void SPI::begin(int bus, int frequency) {
+	mspi = new mraa::Spi(bus);
+
+	mspi->mode(mraa::SPI_MODE0);
+	mspi->bitPerWord(8);
+	mspi->frequency(frequency);
 }
 
 void SPI::end() {
+	// Prophet: we should check for existence of mspi before deleting it
+	if (mspi != NULL)
 		delete mspi;
 }
 
@@ -37,5 +48,6 @@ void SPI::chipSelect(int csn_pin){
 }
 
 SPI::~SPI() {
-
+	// Prophet: we should call end here to free used memory and unexport SPI interface
+	this->end();
 }

arch/MRAA/spi.h

@@ -21,7 +21,9 @@ public:
   inline void transfernb(char* tbuf, char* rbuf, uint32_t len);
   inline void transfern(char* buf, uint32_t len);  
 
-  void begin();
+  void begin(void);
+  // Prophet: A customized SPI::begin can be used with parameters defined as macro in RF24_arch_config.h
+  void begin(int bus, int frequency);
   void end();
 
   void setBitOrder(uint8_t bit_order);