Diff: MMA8652/MMA8652.cpp

Revision:

0:f77369cabd75

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA8652/MMA8652.cpp	Sun Dec 18 08:16:01 2022 +0000
@@ -0,0 +1,118 @@
+/* Copyright (c) 2010-2011 mbed.org, MIT License
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+* and associated documentation files (the "Software"), to deal in the Software without
+* restriction, including without limitation the rights to use, copy, modify, merge, publish,
+* distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in all copies or
+* substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include "MMA8652.h"
+#define UINT14_MAX        16383
+  
+MMA8652::MMA8652(PinName sda, PinName scl) : _i2c(sda, scl) {
+ 
+    begin();
+}
+
+
+MMA8652::~MMA8652() { }
+
+              
+void MMA8652::RegRead( char reg, char * d, int len)
+{
+    char cmd[1];
+    cmd[0] = reg;
+char i2c_addr = MMA8652_SLAVE_ADDR;
+_i2c.write( i2c_addr, cmd, 1, true);
+_i2c.read ( i2c_addr, d, len);
+}
+
+void MMA8652::begin(void)
+{
+    char data[2];
+    // write 0000 0000 = 0x00 to accelerometer control register 1 to place MMA8652 into
+    // standby
+    // [7-1] = 0000 000
+    // [0]: active=0
+    data[0] = MMA8652_CTRL_REG1;
+    data[1] = 0x00;
+    _i2c.write( MMA8652_SLAVE_ADDR, data, 2);
+    
+    // write 0000 0001= 0x01 to XYZ_DATA_CFG register
+    // [7]: reserved
+    // [6]: reserved
+    // [5]: reserved
+    // [4]: hpf_out=0
+    // [3]: reserved
+    // [2]: reserved
+    // [1-0]: fs=00 for accelerometer range of +/-2g range with 0.244mg/LSB
+    data[0] = MMA8652_XYZ_DATA_CFG;
+    data[1] = 0x00;
+    _i2c.write( MMA8652_SLAVE_ADDR, data, 2);
+
+    // write 0000 1101 = 0x0D to accelerometer control register 1
+    // [7-6]: aslp_rate=00
+    // [5-3]: dr=100 for 50Hz data rate
+    // [2]: 0
+    // [1]: 0
+    // [0]: active=1 to take the part out of standby and enable sampling
+    data[0] = MMA8652_CTRL_REG1;
+    data[1] = 0x21;
+    _i2c.write( MMA8652_SLAVE_ADDR, data, 2);
+}
+
+char  MMA8652::getWhoAmI(void)
+{
+    static char d;
+    RegRead( /*MMA8652_WHOAMI*/ 0x0d, &d, 1);
+    return(d);
+}
+
+void MMA8652::ReadXYZ(float * a)
+{
+    char d[7];
+    int16_t t[6];
+
+    RegRead( MMA8652_STATUS, d, 7);
+    t[0] = ((d[1] * 256) + ((unsigned short) d[2]));
+    t[1] = ((d[3] * 256) + ((unsigned short) d[4]));
+    t[2] = ((d[5] * 256) + ((unsigned short) d[6]));
+
+    a[0] = (float) t[0] / 16384.0;
+    a[1] = (float) t[1] / 16384.0;
+    a[2] = (float) t[2] / 16384.0;
+  
+}
+
+
+void MMA8652::ReadXYZraw(int16_t * d)
+{
+char res[6];
+int16_t acc;
+    RegRead( MMA8652_OUT_X_MSB, res, 6);
+
+    acc = (res[0] << 6) | (res[1] >> 2);
+    if (acc > UINT14_MAX/2)
+        acc -= UINT14_MAX;
+    d[0] = acc;
+    acc = (res[2] << 6) | (res[3] >> 2);
+    if (acc > UINT14_MAX/2)
+        acc -= UINT14_MAX;
+    d[1] = acc;
+    acc = (res[4] << 6) | (res[5] >> 2);
+    if (acc > UINT14_MAX/2)
+        acc -= UINT14_MAX;
+    d[2] = acc;
+}
+  
+   
\ No newline at end of file