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Diffstat (limited to 'sensorlib/ak8963.c')
| -rw-r--r-- | sensorlib/ak8963.c | 666 |
1 files changed, 666 insertions, 0 deletions
diff --git a/sensorlib/ak8963.c b/sensorlib/ak8963.c new file mode 100644 index 0000000..5b605a6 --- /dev/null +++ b/sensorlib/ak8963.c @@ -0,0 +1,666 @@ +//*****************************************************************************
+//
+// ak8963.c - Driver for the AK8963 magnetometer.
+//
+// Copyright (c) 2013-2014 Texas Instruments Incorporated. All rights reserved.
+// Software License Agreement
+//
+// Texas Instruments (TI) is supplying this software for use solely and
+// exclusively on TI's microcontroller products. The software is owned by
+// TI and/or its suppliers, and is protected under applicable copyright
+// laws. You may not combine this software with "viral" open-source
+// software in order to form a larger program.
+//
+// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
+// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
+// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
+// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
+// DAMAGES, FOR ANY REASON WHATSOEVER.
+//
+// This is part of revision 2.1.0.12573 of the Tiva Firmware Development Package.
+//
+//*****************************************************************************
+
+#include <stdint.h>
+#include "sensorlib/hw_ak8963.h"
+#include "sensorlib/i2cm_drv.h"
+#include "sensorlib/ak8963.h"
+
+//*****************************************************************************
+//
+//! \addtogroup ak8963_api
+//! @{
+//
+//*****************************************************************************
+
+//*****************************************************************************
+//
+// The states of the AK8963 state machine.
+//
+//*****************************************************************************
+#define AK8963_STATE_IDLE 0 // State machine is idle
+#define AK8963_STATE_READ 1 // Waiting for read
+#define AK8963_STATE_WRITE 2 // Waiting for write
+#define AK8963_STATE_RMW 3 // Waiting for read-modify-write
+
+//*****************************************************************************
+//
+// The factors used to convert the magnetometer readings from the AK8963 into
+// floating point values in tesla
+//
+//*****************************************************************************
+static const float g_fAK8963Factors[] =
+{
+ 0.0000006, // 14-bit = .6 uT/LSB
+ 0.00000015, // 16-bit = .15 uT/LSB
+};
+
+//*****************************************************************************
+//
+// The callback function that is called when I2C transations to/from the
+// AK8963 have completed.
+//
+//*****************************************************************************
+static void
+AK8963Callback(void *pvCallbackData, uint_fast8_t ui8Status)
+{
+ tAK8963 *psInst;
+
+ //
+ // Convert the instance data into a pointer to a tAK8963 structure.
+ //
+ psInst = pvCallbackData;
+
+ //
+ // If the I2C master driver encountered a failure, force the state machine
+ // to the idle state (which will also result in a callback to propagate
+ // the error).
+ //
+ if(ui8Status != I2CM_STATUS_SUCCESS)
+ {
+ psInst->ui8State = AK8963_STATE_IDLE;
+ }
+
+ //
+ // Determine the current state of the AK8963 state machine.
+ //
+ switch(psInst->ui8State)
+ {
+ //
+ // All states that trivially transition to IDLE, and all unknown
+ // states.
+ //
+ case AK8963_STATE_READ:
+ default:
+ {
+ //
+ // The state machine is now idle.
+ //
+ psInst->ui8State = AK8963_STATE_IDLE;
+
+ //
+ // Done.
+ //
+ break;
+ }
+
+ //
+ // A write has just completed.
+ //
+ case AK8963_STATE_WRITE:
+ {
+ //
+ // Set the bit width to the new value. If the register was not
+ // modified, the values will be the same so this has no effect.
+ //
+ psInst->ui8BitOutput = psInst->ui8NewBitOutput;
+
+ //
+ // The state machine is now idle.
+ //
+ psInst->ui8State = AK8963_STATE_IDLE;
+
+ //
+ // Done.
+ //
+ break;
+ }
+
+ //
+ // A read-modify-write just completed
+ //
+ case AK8963_STATE_RMW:
+ {
+ //
+ // See if the AK8963_O_CNTL2 register was just modified.
+ //
+ if(psInst->uCommand.sReadModifyWriteState.pui8Buffer[0] ==
+ AK8963_O_CNTL2)
+ {
+ //
+ // Extract the AK8963_CNTL2_SRST field
+ //
+ if(psInst->uCommand.sReadModifyWriteState.pui8Buffer[1] &
+ AK8963_CNTL2_SRST)
+ {
+ //
+ // A soft reset has happened. Reset the bitoutput
+ // tracking variable
+ //
+ psInst->ui8BitOutput = 0;
+ }
+ }
+
+ //
+ // See if the AK8963_O_CNTL register was just modified.
+ //
+ if(psInst->uCommand.sReadModifyWriteState.pui8Buffer[0] ==
+ AK8963_O_CNTL)
+ {
+ //
+ // Extract the BITM field
+ //
+ psInst->ui8BitOutput =
+ ((psInst->uCommand.sReadModifyWriteState.pui8Buffer[1] &
+ AK8963_CNTL_BITM_M) >> AK8963_CNTL_BITM_S);
+ }
+
+ //
+ // The state machine is now idle.
+ //
+ psInst->ui8State = AK8963_STATE_IDLE;
+
+ //
+ // Done.
+ //
+ break;
+ }
+ }
+
+ //
+ // See if the state machine is now idle and there is a callback function.
+ //
+ if((psInst->ui8State == AK8963_STATE_IDLE) && psInst->pfnCallback)
+ {
+ //
+ // Call the application-supplied callback function.
+ //
+ psInst->pfnCallback(psInst->pvCallbackData, ui8Status);
+ }
+}
+
+//*****************************************************************************
+//
+//! Initializes the AK8963 driver.
+//!
+//! \param psInst is a pointer to the AK8963 instance data.
+//! \param psI2CInst is a pointer to the I2C master driver instance data.
+//! \param ui8I2CAddr is the I2C address of the AK8963 device.
+//! \param pfnCallback is the function to be called when the initialization has
+//! completed (can be \b NULL if a callback is not required).
+//! \param pvCallbackData is a pointer that is passed to the callback function.
+//!
+//! This function initializes the AK8963 driver, preparing it for operation.
+//!
+//! \return Returns 1 if the AK8963 driver was successfully initialized and 0
+//! if it was not.
+//
+//*****************************************************************************
+uint_fast8_t
+AK8963Init(tAK8963 *psInst, tI2CMInstance *psI2CInst, uint_fast8_t ui8I2CAddr,
+ tSensorCallback *pfnCallback, void *pvCallbackData)
+{
+ //
+ // Initialize the AK8963 instance structure.
+ //
+ psInst->psI2CInst = psI2CInst;
+ psInst->ui8Addr = ui8I2CAddr;
+ psInst->ui8State = AK8963_STATE_IDLE;
+ psInst->ui8BitOutput = AK8963_CNTL_BITM_14BIT >> AK8963_CNTL_BITM_S;
+ psInst->ui8NewBitOutput = AK8963_CNTL_BITM_14BIT >> AK8963_CNTL_BITM_S;
+
+ //
+ // The default settings are ok. Return success and call the callback.
+ //
+ if(pfnCallback)
+ {
+ pfnCallback(pvCallbackData, 0);
+ }
+
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Reads data from AK8963 registers.
+//!
+//! \param psInst is a pointer to the AK8963 instance data.
+//! \param ui8Reg is the first register to read.
+//! \param pui8Data is a pointer to the location to store the data that is
+//! read.
+//! \param ui16Count is the number of data bytes to read.
+//! \param pfnCallback is the function to be called when the data has been read
+//! (can be \b NULL if a callback is not required).
+//! \param pvCallbackData is a pointer that is passed to the callback function.
+//!
+//! This function reads a sequence of data values from consecutive registers in
+//! the AK8963.
+//!
+//! \return Returns 1 if the read was successfully started and 0 if it was
+//! not.
+//
+//*****************************************************************************
+uint_fast8_t
+AK8963Read(tAK8963 *psInst, uint_fast8_t ui8Reg, uint8_t *pui8Data,
+ uint_fast16_t ui16Count, tSensorCallback *pfnCallback,
+ void *pvCallbackData)
+{
+ //
+ // Return a failure if the AK8963 driver is not idle (in other words, there
+ // is already an outstanding request to the AK8963).
+ //
+ if(psInst->ui8State != AK8963_STATE_IDLE)
+ {
+ return(0);
+ }
+
+ //
+ // Save the callback information.
+ //
+ psInst->pfnCallback = pfnCallback;
+ psInst->pvCallbackData = pvCallbackData;
+
+ //
+ // Move the state machine to the wait for read state.
+ //
+ psInst->ui8State = AK8963_STATE_READ;
+
+ //
+ // Read the requested registers from the AK8963.
+ //
+ psInst->uCommand.pui8Buffer[0] = ui8Reg;
+ if(I2CMRead(psInst->psI2CInst, psInst->ui8Addr,
+ psInst->uCommand.pui8Buffer, 1, pui8Data, ui16Count,
+ AK8963Callback, psInst) == 0)
+ {
+ //
+ // The I2C write failed, so move to the idle state and return a
+ // failure.
+ //
+ psInst->ui8State = AK8963_STATE_IDLE;
+ return(0);
+ }
+
+ //
+ // Success.
+ //
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Writes data to AK8963 registers.
+//!
+//! \param psInst is a pointer to the AK8963 instance data.
+//! \param ui8Reg is the first register to write.
+//! \param pui8Data is a pointer to the data to write.
+//! \param ui16Count is the number of data bytes to write.
+//! \param pfnCallback is the function to be called when the data has been
+//! written (can be \b NULL if a callback is not required).
+//! \param pvCallbackData is a pointer that is passed to the callback function.
+//!
+//! This function writes a sequence of data values to consecutive registers in
+//! the AK8963. The first byte of the \e pui8Data buffer contains the value to
+//! be written into the \e ui8Reg register, the second value contains the data
+//! to be written into the next register, and so on.
+//!
+//! \return Returns 1 if the write was successfully started and 0 if it was
+//! not.
+//
+//*****************************************************************************
+uint_fast8_t
+AK8963Write(tAK8963 *psInst, uint_fast8_t ui8Reg, const uint8_t *pui8Data,
+ uint_fast16_t ui16Count, tSensorCallback *pfnCallback,
+ void *pvCallbackData)
+{
+ //
+ // Return a failure if the AK8963 driver is not idle (in other words, there
+ // is already an outstanding request to the AK8963).
+ //
+ if(psInst->ui8State != AK8963_STATE_IDLE)
+ {
+ return(0);
+ }
+
+ //
+ // Save the callback information.
+ //
+ psInst->pfnCallback = pfnCallback;
+ psInst->pvCallbackData = pvCallbackData;
+
+ //
+ // See if the CNTL2 register is being written.
+ //
+ if((ui8Reg <= AK8963_O_CNTL2) && ((ui8Reg + ui16Count) > AK8963_O_CNTL2))
+ {
+ //
+ // See if a soft reset is being requested.
+ //
+ if(pui8Data[ui8Reg - AK8963_O_CNTL2] & AK8963_CNTL2_SRST)
+ {
+ //
+ // Update the bit width based on the soft reset.
+ //
+ psInst->ui8NewBitOutput = 0;
+ }
+ }
+
+ //
+ // See if the CNTL register is being written.
+ //
+ if((ui8Reg <= AK8963_O_CNTL) && ((ui8Reg + ui16Count) > AK8963_O_CNTL))
+ {
+ //
+ // Extract the new value of the BITM field from the CNTL register
+ // value.
+ //
+ psInst->ui8NewBitOutput = ((pui8Data[ui8Reg - AK8963_O_CNTL] &
+ AK8963_CNTL_BITM_M) >> AK8963_CNTL_BITM_S);
+ }
+
+ //
+ // Move the state machine to the wait for write state.
+ //
+ psInst->ui8State = AK8963_STATE_WRITE;
+
+ //
+ // Write the requested registers to the AK8963.
+ //
+ if(I2CMWrite8(&(psInst->uCommand.sWriteState), psInst->psI2CInst,
+ psInst->ui8Addr, ui8Reg, pui8Data, ui16Count, AK8963Callback,
+ psInst) == 0)
+ {
+ //
+ // The I2C write failed, so move to the idle state and return a
+ // failure.
+ //
+ psInst->ui8State = AK8963_STATE_IDLE;
+ return(0);
+ }
+
+ //
+ // Success.
+ //
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Performs a read-modify-write of an AK8963 register.
+//!
+//! \param psInst is a pointer to the AK8963 instance data.
+//! \param ui8Reg is the register to modify.
+//! \param ui8Mask is the bit mask that is ANDed with the current register
+//! value.
+//! \param ui8Value is the bit mask that is ORed with the result of the AND
+//! operation.
+//! \param pfnCallback is the function to be called when the data has been
+//! changed (can be \b NULL if a callback is not required).
+//! \param pvCallbackData is a pointer that is passed to the callback function.
+//!
+//! This function changes the value of a register in the AK8963 via a
+//! read-modify-write operation, allowing one of the fields to be changed
+//! without disturbing the other fields. The \e ui8Reg register is read, ANDed
+//! with \e ui8Mask, ORed with \e ui8Value, and then written back to the
+//! AK8963.
+//!
+//! \return Returns 1 if the read-modify-write was successfully started and 0
+//! if it was not.
+//
+//*****************************************************************************
+uint_fast8_t
+AK8963ReadModifyWrite(tAK8963 *psInst, uint_fast8_t ui8Reg,
+ uint_fast8_t ui8Mask, uint_fast8_t ui8Value,
+ tSensorCallback *pfnCallback, void *pvCallbackData)
+{
+ //
+ // Return a failure if the AK8963 driver is not idle (in other words, there
+ // is already an outstanding request to the AK8963).
+ //
+ if(psInst->ui8State != AK8963_STATE_IDLE)
+ {
+ return(0);
+ }
+
+ //
+ // Save the callback information.
+ //
+ psInst->pfnCallback = pfnCallback;
+ psInst->pvCallbackData = pvCallbackData;
+
+ //
+ // Move the state machine to the wait for read-modify-write state.
+ //
+ psInst->ui8State = AK8963_STATE_RMW;
+
+ //
+ // Submit the read-modify-write request to the AK8963.
+ //
+ if(I2CMReadModifyWrite8(&(psInst->uCommand.sReadModifyWriteState),
+ psInst->psI2CInst, psInst->ui8Addr, ui8Reg,
+ ui8Mask, ui8Value, AK8963Callback, psInst) == 0)
+ {
+ //
+ // The I2C read-modify-write failed, so move to the idle state and
+ // return a failure.
+ //
+ psInst->ui8State = AK8963_STATE_IDLE;
+ return(0);
+ }
+
+ //
+ // Success.
+ //
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Reads the magnetometer data from the AK8963.
+//!
+//! \param psInst is a pointer to the AK8963 instance data.
+//! \param pfnCallback is the function to be called when the data has been read
+//! (can be \b NULL if a callback is not required).
+//! \param pvCallbackData is a pointer that is passed to the callback function.
+//!
+//! This function initiates a read of the AK8963 data registers. When the
+//! read has completed (as indicated by calling the callback function), the new
+//! readings can be obtained via:
+//!
+//! - AK8963DataMagnetoGetRaw()
+//! - AK8963DataMagnetoGetFloat()
+//!
+//! \return Returns 1 if the read was successfully started and 0 if it was not.
+//
+//*****************************************************************************
+uint_fast8_t
+AK8963DataRead(tAK8963 *psInst, tSensorCallback *pfnCallback,
+ void *pvCallbackData)
+{
+ //
+ // Return a failure if the AK8963 driver is not idle (in other words, there
+ // is already an outstanding request to the AK8963).
+ //
+ if(psInst->ui8State != AK8963_STATE_IDLE)
+ {
+ return(0);
+ }
+
+ //
+ // Save the callback information.
+ //
+ psInst->pfnCallback = pfnCallback;
+ psInst->pvCallbackData = pvCallbackData;
+
+ //
+ // Move the state machine to the wait for data read state.
+ //
+ psInst->ui8State = AK8963_STATE_READ;
+
+ //
+ // Read the data registers from the AK8963.
+ //
+ // ST1 + (HXL + HXH) + (HYL + HYH) + (HZL + HZH) + ST2 = 8 bytes
+ //
+ psInst->pui8Data[0] = AK8963_O_ST1;
+ if(I2CMRead(psInst->psI2CInst, psInst->ui8Addr, psInst->pui8Data, 1,
+ psInst->pui8Data, 8, AK8963Callback, psInst) == 0)
+ {
+ //
+ // The I2C read failed, so move to the idle state and return a failure.
+ //
+ psInst->ui8State = AK8963_STATE_IDLE;
+ return(0);
+ }
+
+ //
+ // Success.
+ //
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Gets the raw magnetometer data from the most recent data read.
+//!
+//! \param psInst is a pointer to the AK8963 instance data.
+//! \param pui16MagnetoX is a pointer to the value into which the raw X-axis
+//! magnetometer data is stored.
+//! \param pui16MagnetoY is a pointer to the value into which the raw Y-axis
+//! magnetometer data is stored.
+//! \param pui16MagnetoZ is a pointer to the value into which the raw Z-axis
+//! magnetometer data is stored.
+//!
+//! This function returns the raw magnetometer data from the most recent data
+//! read. The data is not manipulated in any way by the driver. If any of the
+//! output data pointers are \b NULL, the corresponding data is not provided.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+AK8963DataMagnetoGetRaw(tAK8963 *psInst, uint_fast16_t *pui16MagnetoX,
+ uint_fast16_t *pui16MagnetoY,
+ uint_fast16_t *pui16MagnetoZ)
+{
+ //
+ // Return the raw magnetometer values.
+ //
+ if(pui16MagnetoX)
+ {
+ *pui16MagnetoX = (psInst->pui8Data[2] << 8) | psInst->pui8Data[1];
+ }
+ if(pui16MagnetoY)
+ {
+ *pui16MagnetoY = (psInst->pui8Data[4] << 8) | psInst->pui8Data[3];
+ }
+ if(pui16MagnetoZ)
+ {
+ *pui16MagnetoZ = (psInst->pui8Data[6] << 8) | psInst->pui8Data[5];
+ }
+}
+
+//*****************************************************************************
+//
+//! Gets the magnetometer data from the most recent data read.
+//!
+//! \param psInst is a pointer to the AK8963 instance data.
+//! \param pfMagnetoX is a pointer to the value into which the X-axis
+//! magnetometer data is stored.
+//! \param pfMagnetoY is a pointer to the value into which the Y-axis
+//! magnetometer data is stored.
+//! \param pfMagnetoZ is a pointer to the value into which the Z-axis
+//! magnetometer data is stored.
+//!
+//! This function returns the magnetometer data from the most recent data read,
+//! converted into tesla. If any of the output data pointers are \b NULL, the
+//! corresponding data is not provided.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+AK8963DataMagnetoGetFloat(tAK8963 *psInst, float *pfMagnetoX,
+ float *pfMagnetoY, float *pfMagnetoZ)
+{
+ float fFactor;
+
+ //
+ // Get the conversion factor for the current data format.
+ //
+ fFactor = g_fAK8963Factors[psInst->ui8BitOutput];
+
+ //
+ // Convert the magnetometer values into floating-point tesla values.
+ //
+ if(pfMagnetoX)
+ {
+ *pfMagnetoX = ((float)(int16_t)((psInst->pui8Data[2] << 8) |
+ psInst->pui8Data[1]) * fFactor);
+ }
+ if(pfMagnetoY)
+ {
+ *pfMagnetoY = ((float)(int16_t)((psInst->pui8Data[4] << 8) |
+ psInst->pui8Data[3]) * fFactor);
+ }
+ if(pfMagnetoZ)
+ {
+ *pfMagnetoZ = ((float)(int16_t)((psInst->pui8Data[6] << 8) |
+ psInst->pui8Data[5]) * fFactor);
+ }
+}
+
+//*****************************************************************************
+//
+//! Gets the status registers from the most recent data read.
+//!
+//! \param psInst is a pointer to the AK8963 instance data.
+//! \param pui8Status1 is a pointer to the value into which the ST1 data is
+//! stored.
+//! \param pui8Status2 is a pointer to the value into which the ST2 data is
+//! stored.
+//!
+//! This function returns the magnetometer status registers from the most
+//! recent data read. If any of the output data pointers are \b NULL, the
+//! corresponding data is not be provided.
+//!
+//! Note that the AKM comp routines require ST1 and ST2, so we read them for
+//! that reason.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+AK8963DataGetStatus(tAK8963 *psInst, uint_fast8_t *pui8Status1,
+ uint_fast8_t *pui8Status2)
+{
+ //
+ // Return the status registers
+ //
+ if(pui8Status1)
+ {
+ *pui8Status1 = psInst->pui8Data[0];
+ }
+ if(pui8Status2)
+ {
+ *pui8Status2 = psInst->pui8Data[7];
+ }
+}
+
+//*****************************************************************************
+//
+// Close the Doxygen group.
+//! @}
+//
+//*****************************************************************************
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