actually adding BMA280 driver files, oops.

git-svn-id: https://afrodevices.googlecode.com/svn/trunk/baseflight@417 7c89a4a9-59b9-e629-4cfe-3a2d53b20e61

src/drv_bma280.c

@@ -0,0 +1,54 @@
+#include "board.h"
+
+// BMA280, default I2C address mode 0x18
+#define BMA280_ADDRESS     0x18
+#define BMA280_ACC_X_LSB   0x02
+#define BMA280_PMU_BW      0x10
+#define BMA280_PMU_RANGE   0x0F
+
+extern uint16_t acc_1G;
+
+static void bma280Init(sensor_align_e align);
+static void bma280Read(int16_t *accelData);
+
+static sensor_align_e accAlign = CW0_DEG;
+
+bool bma280Detect(sensor_t *acc)
+{
+    bool ack = false;
+    uint8_t sig = 0;
+
+    ack = i2cRead(BMA280_ADDRESS, 0x00, 1, &sig);
+    if (!ack || sig != 0xFB)
+        return false;
+
+    acc->init = bma280Init;
+    acc->read = bma280Read;
+    return true;
+}
+
+static void bma280Init(sensor_align_e align)
+{
+    i2cWrite(BMA280_ADDRESS, BMA280_PMU_RANGE, 0x08); // +-8g range
+    i2cWrite(BMA280_ADDRESS, BMA280_PMU_BW, 0x0E); // 500Hz BW
+
+    acc_1G = 512 * 8;
+
+    if (align > 0)
+        accAlign = align;
+}
+
+static void bma280Read(int16_t *accelData)
+{
+    uint8_t buf[6];
+    int16_t data[3];
+
+    i2cRead(BMA280_ADDRESS, BMA280_ACC_X_LSB, 6, buf);
+
+    // Data format is lsb<5:0><crap><new_data_bit> | msb<13:6>
+    data[0] = (int16_t)((buf[0] >> 2) + (buf[1] << 8));
+    data[1] = (int16_t)((buf[2] >> 2) + (buf[3] << 8));
+    data[2] = (int16_t)((buf[4] >> 2) + (buf[5] << 8));
+
+    alignSensors(data, accelData, accAlign);
+}

src/drv_bma280.h

@@ -0,0 +1,3 @@
+#pragma once
+
+bool bma280Detect(sensor_t *acc);