Diff: MMA8451Q_tb.cpp

Revision:

0:7bc6b6007ed1

Child:

1:c6db5b21ad79

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MMA8451Q_tb.cpp	Tue Apr 29 22:26:20 2014 +0000
@@ -0,0 +1,67 @@
+#include "MMA8451Q_tb.h"
+
+#define REG_WHO_AM_I        0x0D
+#define XYZ_DATA_CFG        0x0E
+#define REG_OUT_X_MSB       0x01
+#define REG_OUT_Y_MSB       0x03
+#define REG_OUT_Z_MSB       0x05
+#define REG_SYSMOD          0x0B
+#define REG_CTRL_REG1       0x2A
+
+#define UINT14_MAX          16383
+
+
+MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
+    // activate the peripheral
+    uint8_t data[2] = {REG_CTRL_REG1, 0x01};
+    writeRegs(data, 2);
+}
+
+MMA8451Q::~MMA8451Q() { }
+
+uint8_t MMA8451Q::getWhoAmI() {
+    uint8_t who_am_i = 0;
+    readRegs(REG_WHO_AM_I, &who_am_i, 1);
+    return who_am_i;
+}
+
+float MMA8451Q::getAccX() {
+//divide by 4096 b/c MMA output is 4096 counts per g so this f outputs accelorometer value formatted to g (gravity)
+    return (float(getAccAxis(REG_OUT_X_MSB))/4096.0);
+}
+
+float MMA8451Q::getAccY() {
+    return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0);
+}
+
+float MMA8451Q::getAccZ() {
+    return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0);
+}
+
+void MMA8451Q::getAccAllAxis(float * res) {
+    res[0] = getAccX();
+    res[1] = getAccY();
+    res[2] = getAccZ();
+}
+
+int16_t MMA8451Q::getAccAxis(uint8_t addr) {
+    int16_t acc;
+    uint8_t res[2];
+    readRegs(addr, res, 2);
+
+    acc = (res[0] << 6) | (res[1] >> 2);
+    if (acc > UINT14_MAX/2)
+        acc -= UINT14_MAX;
+
+    return acc;
+}
+
+void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
+    char t[1] = {addr};
+    m_i2c.write(m_addr, t, 1, true);
+    m_i2c.read(m_addr, (char *)data, len);
+}
+
+void MMA8451Q::writeRegs(uint8_t * data, int len) {
+    m_i2c.write(m_addr, (char *)data, len);
+}
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