Diff: main.cpp

Revision:

0:775d3ce39c34

Child:

1:5aebe57872ed

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Apr 08 11:30:55 2016 +0000
@@ -0,0 +1,103 @@
+#include "mbed.h"
+#include "Adafruit_SSD1306.h"
+
+//Switch input definition
+#define SW_PIN p22
+
+//Sampling period for the switch oscillator (us)
+#define SW_PERIOD 20000 
+
+//Display interface pin definitions
+#define D_MOSI_PIN p5
+#define D_CLK_PIN p7
+#define D_DC_PIN p8
+#define D_RST_PIN p9
+#define D_CS_PIN p10
+
+//an SPI sub-class that sets up format and clock speed
+class SPIPreInit : public SPI
+{
+public:
+    SPIPreInit(PinName mosi, PinName miso, PinName clk) : SPI(mosi,miso,clk)
+    {
+        format(8,3);
+        frequency(2000000);
+    };
+};
+
+//Interrupt Service Routine prototypes (functions defined below)
+void sedge();
+void tout();
+
+//Output for the alive LED
+DigitalOut alive(LED1);
+
+//External interrupt input from the switch oscillator
+InterruptIn swin(SW_PIN);
+
+//Switch sampling timer
+Ticker swtimer;
+
+//Registers for the switch counter, output register and update flag
+uint16_t scounter=0,scount=0,update=0;
+
+//Initialise SPI instance for communication with the display
+SPIPreInit gSpi(D_MOSI_PIN,NC,D_CLK_PIN); //MOSI,MISO,CLK
+
+//Initialise display driver instance
+Adafruit_SSD1306_Spi gOled1(gSpi,D_DC_PIN,D_RST_PIN,D_CS_PIN,64,128); //SPI,DC,RST,CS,Height,Width
+
+int main() { 
+    //Initialisation
+    
+    //Attach switch oscillator counter ISR to the switch input instance for a rising edge
+    swin.rise(&sedge);
+    
+    //Attach switch sampling timer ISR to the timer instance with the required period
+    swtimer.attach_us(&tout, SW_PERIOD);
+    
+    //Write some sample text
+    gOled1.printf("%ux%u OLED Display\r\n", gOled1.width(), gOled1.height());
+    
+    //Main loop
+    while(1)
+    {
+        //Has the update flag been set?       
+        if (update) {
+            //Clear the update flag
+            update = 0;
+            
+            //Set text cursor
+            gOled1.setTextCursor(0,0);
+            
+            //Write the latest switch osciallor count
+            gOled1.printf("\n%05u  ",scount);
+            
+            //Copy the display buffer to the display
+            gOled1.display();
+            
+            //Toggle the alive LED
+            alive = !alive;
+        }
+        
+        
+    }
+}
+
+
+//Interrupt Service Request for rising edge on the switch oscillator input
+void sedge() {
+    //Increment the edge counter
+    scounter++;    
+}
+
+//Interrupt Service Request for the switch sampling timer
+void tout() {
+    //Read the edge counter into the output register
+    scount = scounter;
+    //Reset the edge counter
+    scounter = 0;
+    //Trigger a display update in the main loop
+    update = 1;
+}
+