Diff: main.cpp

Revision:

0:06dc60296e6e

diff -r 000000000000 -r 06dc60296e6e main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jul 03 20:05:55 2014 +0000
@@ -0,0 +1,91 @@
+#include "mbed.h"
+#include "BMP180.h"
+#include "HT16K33.h"
+ 
+#define BMP180_ADDRESS 0x77<<1
+
+uint32_t delt_t, count, tempcount;
+float temperature, pressure, temppress, altitude;
+
+DigitalOut myled(LED1);
+ 
+BMP180 bmp180; // initialize BMP-180 altimeter
+
+HT16K33 led; // initialize bubble display
+
+Timer t;
+
+Serial pc(USBTX, USBRX); // tx, rx
+ 
+int main() {
+ 
+   t.start();
+   
+   led.initHT16K33();          // initialize bubble display
+   led.clearDsplay(display1);  // clear bubble display1
+   led.clearDsplay(display2);  // clear bubble display2
+   led.clearDsplay(display3);  // clear bubble display1
+   led.clearDsplay(display4);  // clear bubble display2
+
+  // Read the WHO_AM_I register of the BMP-180, this is a good test of communication
+    uint8_t c = bmp180.readByte(BMP180_ADDRESS, BMP180_WHO_AM_I);   
+    if(c == 0x55) {
+ 
+    pc.printf("BMP-180 is 0x%x\n\r", c);
+    pc.printf("BMP-180 should be 0x55\n\r");
+    pc.printf("BMP-180 online...\n\r");
+   
+    bmp180.BMP180Calibration();
+    pc.printf("BMP-180 calibration complete...\n\r");
+   }
+   else 
+   {
+    pc.printf("BMP-180 is 0x%x\n\r", c);
+    pc.printf("BMP-180 should be 0x55\n\r");
+    while(1); // idle here forever
+   }
+   
+    /////////////////////////////////////////////////
+    // main
+    /////////////////////////////////////////////////
+ 
+    while (1) {
+
+    // Average over the display duty cycle to get the best pressure and altitude resolution
+    // The sample read time is on the order of 30 ms at the highest resolution using OSS = 3
+    // Averaging over the display duty cycle is equivalent to averaging about 500/30 ~ 16 times
+    // per display output. If this is too much averaging, one can always reduce the display duty cycle
+    
+    temperature = (float)bmp180.BMP180GetTemperature()/10.0f;  // Get temperature from BMP-180 in degrees C
+    temppress += (float)bmp180.BMP180GetPressure();            // Get pressure from BMP-180 in Pa
+    tempcount++;
+
+    // Serial print and/or display at 0.5 s rate independent of data rates
+    delt_t = t.read_ms() - count;
+    if (delt_t > 500) { // update LCD once per half-second independent of read rate
+
+    myled=!myled;
+   
+    pressure = temppress/tempcount;  // use average pressure for reading to get ultra-high resolution
+    temperature = temperature*9.0f/5.0f + 32.0f;                          // convert to Fahrenheit
+    altitude = 44330.0f*( 1.0f - pow((pressure/101325.0f), (1.0f/5.255f))); // Calculate altitude in meters
+   
+    led.writeFloat(display1, temperature, 1);             // display temperature in degrees Fahrenheit to bubble display
+    led.writeFloat(display2, pressure/1000, 2);           // display pressure in mPa to bubble display
+    led.writeFloat(display3, altitude, 1);                // display altitude in meters to bubble display
+    led.writeFloat(display4, altitude*3.281f, 1);          // display altitude in feet to bubble display
+
+    pc.printf("Temperature is  %.1f C\n\r", temperature); 
+    pc.printf("Pressure is  %.3f mPa\n\r", pressure/1000.0f); 
+    pc.printf("Altitude is  %.1f m\n\r", altitude);
+    pc.printf("Altitude is  %.1f ft\n\r", altitude*3.2810f); 
+    pc.printf("\n\r");
+  
+                
+    count = t.read_ms();  
+    temppress = 0;
+    tempcount = 0;
+    }
+    }
+}
+