src/main/drivers/compass/compass_mpu925x_ak8963.c

   1 /*
   2  * This file is part of Cleanflight.
   3  *
   4  * Cleanflight is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Cleanflight is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <stdbool.h>
  19 #include <stdint.h>
  20
  21 #include "platform.h"
  22
  23 #include "drivers/bus.h"
  24 #include "drivers/sensor.h"
  25 #include "drivers/system.h"
  26 #include "drivers/time.h"
  27
  28 #include "drivers/accgyro/accgyro_mpu.h"
  29
  30 #include "drivers/compass/compass.h"
  31 #include "drivers/compass/compass_ak8963.h"
  32 #include "drivers/compass/compass_mpu925x_ak8963.h"
  33
  34 #if defined(USE_MAG_MPU925X_AK8963)
  35
  36 #define MPU925X_I2C_ADDRESS             0x68
  37 #define AK8963_MAG_I2C_ADDRESS          0x0C
  38 #define MPU9250_BIT_RESET               0x80
  39
  40 static bool mpu925xDeviceDetect(const extDevice_t * dev)
  41 {
  42     busWriteRegister(dev, MPU_RA_PWR_MGMT_1, MPU9250_BIT_RESET);
  43     delay(150);
  44     switch (busReadRegister(dev, MPU_RA_WHO_AM_I)) {
  45         case MPU9250_WHO_AM_I_CONST:
  46         case MPU9255_WHO_AM_I_CONST:
  47             return true;
  48         default:
  49             return false;
  50     }
  51 }
  52
  53 bool mpu925Xak8963CompassDetect(magDev_t * mag)
  54 {
  55     extDevice_t *dev = &mag->dev;
  56     busDeviceRegister(dev);
  57     if (!mpu925xDeviceDetect(dev->bus->busType_u.mpuSlave.master)) {
  58         return false;
  59     }
  60     // set bypass mode on mpu9250
  61     busWriteRegister(dev->bus->busType_u.mpuSlave.master, MPU_RA_INT_PIN_CFG, 0x02);
  62     delay(150);
  63     // now we have ak8963 alike on the bus
  64     dev->busType_u.i2c.address = AK8963_MAG_I2C_ADDRESS;
  65     busDeviceRegister(dev);
  66     if(!ak8963Detect(mag)) {
  67         // if ak8963 is not detected, reset the MPU to disable bypass mode
  68         dev->busType_u.i2c.address = MPU925X_I2C_ADDRESS;
  69         busWriteRegister(dev, MPU_RA_PWR_MGMT_1, MPU9250_BIT_RESET);
  70         return false;
  71     } else {
  72         return true;
  73     }
  74 }
  75
  76 #endif