grove_accelerometer.cpp

00001 
00002 
00003 #include "suli2.h"
00004 #include "grove_accelerometer.h"
00005 
00006 
00007 
00008 //local functions
00009 static void grove_accelerometer_setmode(I2C_T *i2c, uint8_t mode);
00010 static void grove_accelerometer_setsamplerate(I2C_T *i2c, uint8_t rate);
00011 static void grove_accelerometer_getxyz(I2C_T *i2c, int8_t *x, int8_t *y, int8_t *z);
00012 
00013 //local variables
00014 static unsigned char cmdbuf[2];
00015 
00016 
00017 void grove_accelerometer_init(I2C_T *i2c, int pinsda, int pinscl)
00018 {
00019     suli_i2c_init(i2c, pinsda, pinscl);
00020 }
00021 
00022 bool grove_accelerometer_write_setup(I2C_T *i2c)
00023 {
00024     grove_accelerometer_setmode(i2c, MMA7660_STAND_BY);
00025     grove_accelerometer_setsamplerate(i2c, AUTO_SLEEP_32);
00026     grove_accelerometer_setmode(i2c, MMA7660_ACTIVE);
00027     
00028     return true;
00029 }
00030 
00031 static void grove_accelerometer_setmode(I2C_T *i2c, uint8_t mode)
00032 {
00033     //write(MMA7660_MODE,mode); 
00034     cmdbuf[0] = MMA7660_MODE;
00035     cmdbuf[1] = mode;
00036     suli_i2c_write(i2c, MMA7660_ADDR, cmdbuf, 2);
00037     
00038 }
00039 static void grove_accelerometer_setsamplerate(I2C_T *i2c, uint8_t rate)
00040 {
00041     //write(MMA7660_SR,rate);
00042     cmdbuf[0] = MMA7660_SR;
00043     cmdbuf[1] = rate;
00044     suli_i2c_write(i2c, MMA7660_ADDR, cmdbuf, 2);
00045 }
00046 
00047 /*Function: Get the contents of the registers in the MMA7660*/
00048 /*          so as to calculate the acceleration.            */
00049 static void grove_accelerometer_getxyz(I2C_T *i2c, int8_t *x, int8_t *y, int8_t *z)
00050 {
00051     unsigned char val[3];
00052     val[0] = val[1] = val[2] = 64;
00053 
00054     suli_i2c_read(i2c, MMA7660_ADDR, val, 3);
00055     
00056     *x = ((char)(val[0]<<2))/4;
00057     *y = ((char)(val[1]<<2))/4;
00058     *z = ((char)(val[2]<<2))/4;
00059 }
00060 
00061 bool grove_accelerometer_getacceleration(I2C_T *i2c, float *ax, float *ay, float *az)
00062 {
00063     int8_t x,y,z;
00064     grove_accelerometer_getxyz(i2c, &x,&y,&z);
00065     *ax = x/21.00;
00066     *ay = y/21.00;
00067     *az = z/21.00;
00068     
00069     return true;
00070 }
00071 
00072