Diff: main.cpp

Revision:

0:d847fd15f903

diff -r 000000000000 -r d847fd15f903 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat May 12 14:27:40 2012 +0000
@@ -0,0 +1,150 @@
+/*
+Gyroscope Interfacing
+After recieving 16bit from Gyro if 15th bit is zero, the instruction is accepted
+*/
+
+#include "mbed.h"
+SPI spi(p5, p6, p7); // mosi, miso, sclk
+DigitalOut csGyro(p8);
+Serial pc(USBTX, USBRX); // tx, rx
+
+void activateADC()
+{
+    unsigned int data1, data2;
+    csGyro=0;
+    spi.write(0x93); // 0b10010100
+    /*Check if instruction recieved i.e  */
+    //Send 2 dymmy byte of any combination
+    data1 = spi.write(0x00);
+    data2 = spi.write(0x00);
+    wait_us(200);
+    csGyro=1;
+    
+    if(data1 & 0x80) /*0b10000000*/
+    {
+        pc.printf("\nInstruction not recieved %d %d", &data1, &data2);
+    }
+    else
+        pc.printf("\n ADC activated  ");
+}
+
+void sleepADC()
+{
+	unsigned int data1, data2;
+	csGyro=0;
+    spi.write(0x90); // 0b10010000
+    /*Check if instruction recieved i.e  */
+    //Send 2 dymmy byte of any combination
+    data1 = spi.write(0x00);
+    data2 = spi.write(0x00);
+    wait_us(200);
+    csGyro=1;
+    
+    if(data1 & 0x80) /*0b10000000*/
+    {
+        pc.printf("\nInstruction not recieved %d %d", &data1, &data2);
+    }
+    else
+        pc.printf("\n ADC in sleep ");
+}
+
+unsigned int getAngularRate()
+{
+    unsigned int result=0, data1, data2;
+    csGyro=0;
+    spi.write(0x94); /* 0b10010100 Send SPI ADCC for Angular Rate (CHAN bit = 0)*/
+    /*Check if instruction recieved*/
+    //Send 2 dymmy byte of any combination
+    data1 = spi.write(0x00);
+    data2 = spi.write(0x00);
+    wait_us(200);
+    csGyro=1;
+    
+    if(data1 & 0x80 ) /*0b10000000*/
+    {
+        pc.printf("\nInstruction not recieved");
+    }
+
+    csGyro=0;
+    spi.write(0x80); /* 0b10000000 Send SPI ADCR Instruction*/
+    /*Send 2 dymmy byte*/
+    data1 = spi.write(0x00);
+    data2 = spi.write(0x00);
+    wait_us(200);
+    csGyro=1;
+    
+    /*Check if instruction recieved*/
+    if(!(data1 & 0x80))
+    {
+        while(!(data1 & 0x20)); // Wait while EOC is 0
+        result = ((data1 & 0x0F) << 7) + (data2>>1);
+    }
+    return result;
+   
+}
+
+unsigned int getTemperature()
+{
+    unsigned int result=0, data1, data2;
+    csGyro=0;
+    spi.write(0x9C); /* 0b10011100 Send SPI ADCC for Temperature (CHAN bit = 1)*/
+    /*Check if instruction recieved*/
+    //Send 2 dymmy byte of any combination
+    data1 = spi.write(0x00);
+    data2 = spi.write(0x00);
+    wait_us(200);
+    csGyro=1;
+    
+    if(data1 & 0x80 ) /*0b10000000*/
+    {
+        pc.printf("\nInstruction not recieved");
+    }
+
+    csGyro=0;
+    spi.write(0x80); /* 0b10000000 Send SPI ADCR Instruction*/
+    /*Send 2 dymmy byte*/
+    data1 = spi.write(0x00);
+    data2 = spi.write(0x00);
+    wait_us(200);
+    csGyro=1;
+    
+    /*Check if instruction accepted*/
+    if(!(data1 & 0x80))
+    {
+        while(!(data1 & 0x20)); // Wait while EOC is 0
+        result = ((data1 & 0x0F) << 7) + (data2>>1);
+    }
+    return result;
+}
+
+int adcToAngularRate(unsigned int result)
+{
+    int conversion = (result * 25/12)+400;
+    signed int offset = 2500;
+    return (conversion - offset)/6.67; /*from the data sheet, R2 version is 6.67 E2 is 13.33 and N2 is 26.67 mV/deg change accordingly.*/
+}
+
+int adcToTemperature(unsigned int result)
+{
+    
+    int conversion = (result * 25/16)+300;
+    signed int offset = 2500;
+    return 25 + ((conversion - offset)/10); /* from the data sheet factor is 10mV/K */
+}
+
+int main()
+{
+    unsigned int angle, temper;
+    spi.format(8,3);
+    spi.frequency(1000000);
+    while(1){
+    activateADC();
+    
+    angle=getAngularRate();
+    temper=getTemperature();
+    pc.printf("\nAngular Rate %d",adcToAngularRate(angle));
+    pc.printf("\nTemperature %d",adcToTemperature(temper));
+    sleepADC();
+    wait(1);
+    }
+}
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