Diff: ACCEL_ADXL345.cpp

Revision:

0:82a02991476c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ACCEL_ADXL345.cpp	Sat Sep 08 20:40:58 2012 +0000
@@ -0,0 +1,104 @@
+#include "ACCEL_ADXL345.h"
+#include "mbed.h"
+
+void accel_ISR() {
+    accelRdy = true;
+    accelTime = timer.read_us();
+    updateAccel();
+}
+
+void updateAccel() {
+  
+    __disable_irq();// if we are interrupted here i could mean we get accel data from 2 different samples
+    _cs = 0;
+    _spi.write(0xF2);   // Read X out reg and have it continue for 6 bytes
+    xraw0 =  _spi.write(0x0);
+    xraw1 =  _spi.write(0x0);
+    yraw0 =  _spi.write(0x0);
+    yraw1 =  _spi.write(0x0);
+    zraw0 =  _spi.write(0x0);
+    zraw1 =  _spi.write(0x0);
+    _cs = 1;
+    __enable_irq();
+    
+    //pc.printf(" X1=%i, X0=%i, Y1=%i, Y0=%i, Z1=%i, Z0=%i, \n",xraw1,xraw0,yraw1,yraw0,zraw1,zraw0);
+
+    //   pc.printf("%d %d %d",xaxis,yaxis,zaxis);
+}
+
+void convertAccel(){
+  xaxis = (float)(xraw0 | (xraw1 << 8))/250.0;//(((xraw1 & 0x01) | ((xraw1&0x01)<<3) )<< 8));
+  yaxis = (float)(yraw0 | (yraw1 << 8))/250.0;//(((yraw1 & 0x01) | ((yraw1&0x01)<<3) ) << 8));
+  zaxis = (float)(zraw0 | (zraw1 << 8))/250.0;//(((zraw1 & 0x01) | ((zraw1&0x01)<<3) ) << 8));
+
+}
+
+
+void initAccel() {
+
+    // Taken from datasheet
+    // 8 bit data
+    // High steady state clock
+    // Second edge capture
+    _spi.format(8,3);
+
+    // 5MHz clock rate
+    _spi.frequency(1000000);
+
+    // Select the device, active low chip select
+    _cs = 0;
+
+    _spi.write(0x31); // set data_format to 0b00000001 to turn on 4 wire mode with act high interrupts,10 bit mode and +- 4g operation
+    _spi.write(0x0B);
+    // end this transfer
+    _cs = 1;
+
+
+    wait (0.01); //this is stupid, get rid of it
+
+
+// new transfer
+    _cs = 0;
+
+    _spi.write(0x5D); // start writing at 0x1D but turn on sequential writes so we can set everything in one fowl swoop
+
+    _spi.write(0xFF);  // set THRESH_TAP - only used when corresponding interrupt is enabled
+    _spi.write(0x00); // set OFSX
+    _spi.write(0x00); // set OFSY
+    _spi.write(0x00); // set OFSZ
+    _spi.write(0xFF); // set DUR (min duration to be considered a TAP event)
+    _spi.write(0x00); // set Latent (max duration between TAP events)
+    _spi.write(0x00); // set Window (max time after a Latency to be in the same TAP window)
+    _spi.write(0x00); // set THRESH_ACT - only used when corresponding interrupt is enabled
+    _spi.write(0x00); // set THRESH_INACT - only used when corresponding interrupt is enabled
+    _spi.write(0xFF); // set TIME_INACT - only used when corresponding interrupt is enabled
+    _spi.write(0x00); // set ACT_INACT_CTL - AC/DC coupling for activity registers + enabling/disabling in x,y.z - only used when corresponding interrupt is enabled
+    _spi.write(0xFF); // set THRESH_FF (free fall) - only used when corresponding interrupt is enabled
+    _spi.write(0xFF); // set TIME_FF (free fall)
+    _spi.write(0x00); // set TAP_AXES (with 0x00 we are disabling all tap detection)
+    // end this transfer
+    _cs = 1;
+
+// start another multiple byte transfer
+    _cs = 0;
+    _spi.write(0x6C); // another sequential write starting at 0x2C
+    _spi.write(0x0E); // set BW_RATE to disable low power and turn on max bandwidth
+    _spi.write(0x0B); // set // set PWR_CTRL to start measurments, and not be asleep , and to do 8hz measurements if asleep
+    _spi.write(0x00); // set INT_ENABLE
+    _spi.write(0x00); // set INT_MAP - send all interrupts to INT1 but doesnt really matter because we wont use this (yet)
+    _cs = 1;
+
+    // start new transfer
+    _cs = 0;
+    _spi.write(0x38); // FIFO_CTL
+    _spi.write(0x00); // disable the FIFO
+    _cs = 1;
+
+    _cs = 0;
+    _spi.write(0x80);
+    wait(.1);
+    devid = _spi.write(0x0);
+    _cs  = 1;
+    accel.attach_us(&accel_ISR, 625);
+    accelRdy = false;
+}