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Diffstat (limited to 'sensorlib/cm3218.c')
| -rw-r--r-- | sensorlib/cm3218.c | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/sensorlib/cm3218.c b/sensorlib/cm3218.c new file mode 100644 index 0000000..bb2251f --- /dev/null +++ b/sensorlib/cm3218.c @@ -0,0 +1,468 @@ +//*****************************************************************************
+//
+// cm3218.c - Driver for the CM3218 light sensor
+//
+// 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 <math.h>
+#include <stdint.h>
+#include "sensorlib/hw_cm3218.h"
+#include "sensorlib/i2cm_drv.h"
+#include "sensorlib/cm3218.h"
+
+//*****************************************************************************
+//
+//! \addtogroup cm3218_api
+//! @{
+//
+//*****************************************************************************
+
+//*****************************************************************************
+//
+// The states of the CM3218 state machine.
+//
+//*****************************************************************************
+#define CM3218_STATE_IDLE 0
+#define CM3218_STATE_INIT 1
+#define CM3218_STATE_READ 2
+#define CM3218_STATE_WRITE 3
+
+//*****************************************************************************
+//
+// Sensitivity setting to floating point range value lookup table.
+//
+//*****************************************************************************
+const float g_pfSensitivityLookup[4] =
+{
+ 0.02857,
+ 0.01328,
+ 0.00714,
+ 0.003571
+};
+
+//*****************************************************************************
+//
+// The callback function that is called when I2C transations to/from the CM3218
+// have completed.
+//
+//*****************************************************************************
+static void
+CM3218Callback(void *pvCallbackData, uint_fast8_t ui8Status)
+{
+ tCM3218 *psInst;
+
+ //
+ // Convert the instance data into a pointer to a tCM3218 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 = CM3218_STATE_IDLE;
+ }
+
+ //
+ // Determine the current state of the CM3218 state machine.
+ //
+ switch(psInst->ui8State)
+ {
+ //
+ // All states that trivially transition to IDLE, and all unknown
+ // states.
+ //
+ case CM3218_STATE_INIT:
+ case CM3218_STATE_READ:
+ default:
+ {
+ //
+ // The state machine is now idle.
+ //
+ psInst->ui8State = CM3218_STATE_IDLE;
+ break;
+ }
+
+ //
+ // A write has just completed.
+ //
+ case CM3218_STATE_WRITE:
+ {
+ //
+ // Set the integration time to the new integration time. If the
+ // register was not modified, the values will be the same so this
+ // has no effect.
+ //
+ psInst->ui8IntTime = psInst->ui8NewIntTime;
+
+ //
+ // The state machine is now idle.
+ //
+ psInst->ui8State = CM3218_STATE_IDLE;
+
+ //
+ // Done.
+ //
+ break;
+ }
+ }
+
+ //
+ // See if the state machine is now idle and there is a callback function.
+ //
+ if((psInst->ui8State == CM3218_STATE_IDLE) && psInst->pfnCallback)
+ {
+ //
+ // Call the application-supplied callback function.
+ //
+ psInst->pfnCallback(psInst->pvCallbackData, ui8Status);
+ }
+}
+
+//*****************************************************************************
+//
+//! Initializes the CM3218 driver.
+//!
+//! \param psInst is a pointer to the CM3218 instance data.
+//! \param psI2CInst is a pointer to the I2C driver instance data.
+//! \param ui8I2CAddr is the I2C address of the CM3218 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 CM3218 driver, preparing it for operation.
+//!
+//! \return Returns 1 if the CM3218 driver was successfully initialized and 0
+//! if it was not.
+//
+//*****************************************************************************
+uint_fast8_t
+CM3218Init(tCM3218 *psInst, tI2CMInstance *psI2CInst, uint_fast8_t ui8I2CAddr,
+ tSensorCallback *pfnCallback, void *pvCallbackData)
+{
+ //
+ // Initialize the CM3218 instance structure
+ //
+ psInst->psI2CInst = psI2CInst;
+ psInst->ui8Addr = ui8I2CAddr;
+ psInst->ui8State = CM3218_STATE_IDLE;
+ psInst->ui8IntTime = CM3218_CMD_CONFIG_IT_10 >> CM3218_CMD_CONFIG_IT_S;
+ psInst->ui8NewIntTime = CM3218_CMD_CONFIG_IT_10 >> CM3218_CMD_CONFIG_IT_S;
+
+ //
+ // The default settings are ok. Call the callback function if provided.
+ //
+ if(pfnCallback)
+ {
+ pfnCallback(pvCallbackData, 0);
+ }
+
+ //
+ // Success
+ //
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Reads data from CM3218 registers.
+//!
+//! \param psInst is a pointer to the CM3218 instance data.
+//! \param ui8Reg is the first register to read.
+//! \param pui16Data is a pointer to the location to store the data that is
+//! read.
+//! \param ui16Count the number of register values bytes to read.
+//! \param pfnCallback is the function to be called when data read is complete
+//! (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 CM3218.
+//!
+//! \note The CM3218 does not auto-increment the register pointer, so reads of
+//! more than one value returns the same data.
+//!
+//! \return Returns 1 if the write was successfully started and 0 if it was
+//! not.
+//
+//*****************************************************************************
+uint_fast8_t
+CM3218Read(tCM3218 *psInst, uint_fast8_t ui8Reg, uint16_t *pui16Data,
+ uint_fast16_t ui16Count, tSensorCallback *pfnCallback,
+ void *pvCallbackData)
+{
+ //
+ // Return a failure if the CM3218 driver is not idle (in other words, there
+ // is already an outstanding request to the CM3218).
+ //
+ if(psInst->ui8State != CM3218_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 = CM3218_STATE_READ;
+
+ //
+ // Read the requested registers from the CM3218.
+ //
+ if(I2CMRead16BE(&(psInst->uCommand.sReadState), psInst->psI2CInst,
+ psInst->ui8Addr, ui8Reg, pui16Data, ui16Count,
+ CM3218Callback, psInst) == 0)
+ {
+ //
+ // The I2C write failed, so move to the idle state and return a
+ // failure.
+ //
+ psInst->ui8State = CM3218_STATE_IDLE;
+ return(0);
+ }
+
+ //
+ // Success.
+ //
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Writes data to CM3218 registers.
+//!
+//! \param psInst is a pointer to the CM3218 instance data.
+//! \param ui8Reg is the first register to write.
+//! \param pui16Data is a pointer to the 16-bit register 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 CM3218. The first value in the \e pui16Data buffer contains the data
+//! to be written into the \e ui8Reg register, the second value contains the
+//! data to be written into the next register, and so on.
+//!
+//! \note The CM3218 does not auto-increment the register pointer, so writes of
+//! more than one register are rejected by the CM3218.
+//!
+//! \return Returns 1 if the write was successfully started and 0 if it was
+//! not.
+//
+//*****************************************************************************
+uint_fast8_t
+CM3218Write(tCM3218 *psInst, uint_fast8_t ui8Reg, const uint16_t *pui16Data,
+ uint_fast16_t ui16Count, tSensorCallback *pfnCallback,
+ void *pvCallbackData)
+{
+ //
+ // Return a failure if the CM3218 driver is not idle (in other words, there
+ // is already an outstanding request to the CM3218).
+ //
+ if(psInst->ui8State != CM3218_STATE_IDLE)
+ {
+ return(0);
+ }
+
+ //
+ // Save the callback information.
+ //
+ psInst->pfnCallback = pfnCallback;
+ psInst->pvCallbackData = pvCallbackData;
+
+ //
+ // See if the CMD_CONFIG register is being written.
+ //
+ if((ui8Reg <= CM3218_CMD_CONFIG) &&
+ ((ui8Reg + ui16Count) > CM3218_CMD_CONFIG))
+ {
+ //
+ // Extract the integration time from the CMD_CONFIG register value.
+ //
+ psInst->ui8NewIntTime = ((pui16Data[ui8Reg - CM3218_CMD_CONFIG] &
+ CM3218_CMD_CONFIG_IT_M) >>
+ CM3218_CMD_CONFIG_IT_S);
+ }
+
+ //
+ // Move the state machine to the wait for write state.
+ //
+ psInst->ui8State = CM3218_STATE_WRITE;
+
+ //
+ // Write the requested registers to the CM3218.
+ //
+ if(I2CMWrite16BE(&(psInst->uCommand.sWriteState), psInst->psI2CInst,
+ psInst->ui8Addr, ui8Reg, pui16Data, ui16Count,
+ CM3218Callback, psInst) == 0)
+ {
+ //
+ // The I2C write failed, so move to the idle state and return a
+ // failure.
+ //
+ psInst->ui8State = CM3218_STATE_IDLE;
+ return(0);
+ }
+
+ //
+ // Success.
+ //
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Reads the light data from the CM3218.
+//!
+//! \param psInst is a pointer to the CM3218 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 CM3218 data registers. When the read
+//! has completed (as indicated by calling the callback function), the new
+//! readings can be obtained via:
+//!
+//! - CM3218DataLightVisibleGetRaw()
+//! - CM3218DataLightVisibleGetFloat()
+//!
+//! \return Returns 1 if the read was successfully started and 0 if it was not.
+//
+//*****************************************************************************
+uint_fast8_t
+CM3218DataRead(tCM3218 *psInst, tSensorCallback *pfnCallback,
+ void *pvCallbackData)
+{
+ //
+ // Return a failure if the CM3218 driver is not idle (in other words, there
+ // is already an outstanding request to the CM3218).
+ //
+ if(psInst->ui8State != CM3218_STATE_IDLE)
+ {
+ return(0);
+ }
+
+ //
+ // Save the callback information.
+ //
+ psInst->pfnCallback = pfnCallback;
+ psInst->pvCallbackData = pvCallbackData;
+
+ //
+ // Move the state machine to the wait for data read
+ //
+ psInst->ui8State = CM3218_STATE_READ;
+
+ //
+ // Read the ambient light data from the CM3218.
+ //
+ psInst->uCommand.pui8Buffer[0] = CM3218_CMD_ALS_DATA;
+ if(I2CMRead(psInst->psI2CInst, psInst->ui8Addr,
+ psInst->uCommand.pui8Buffer, 1, psInst->pui8Data, 2,
+ CM3218Callback, psInst) == 0)
+ {
+ //
+ // The I2C read failed, so move to the idle state and return a failure.
+ //
+ psInst->ui8State = CM3218_STATE_IDLE;
+ return(0);
+ }
+
+ //
+ // Success.
+ //
+ return(1);
+}
+
+//*****************************************************************************
+//
+//! Gets the raw measurement data from the most recent data read.
+//!
+//! \param psInst is a pointer to the CM3218 instance data.
+//! \param pui16Visible is a pointer to the value into which the raw visible
+//! light data is stored.
+//!
+//! This function returns the raw measurement data from the most recent data
+//! read. The data is not manipulated in any way by the driver.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+CM3218DataLightVisibleGetRaw(tCM3218 *psInst, uint16_t *pui16Visible)
+{
+ //
+ // Return the raw Light value.
+ //
+ *pui16Visible = (psInst->pui8Data[1] << 8) | psInst->pui8Data[0];
+}
+
+//*****************************************************************************
+//
+//! Gets the measurement data from the most recent data read.
+//!
+//! \param psInst is a pointer to the CM3218 instance data.
+//! \param pfVisibleLight is a pointer to the value into which the light
+//! data is stored as floating point lux.
+//!
+//! This function returns the light data from the most recent data read,
+//! converted into lux.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+CM3218DataLightVisibleGetFloat(tCM3218 *psInst, float *pfVisibleLight)
+{
+ uint16_t ui16Light;
+ float fSensitivity;
+
+ //
+ // Get the raw light data from the instance structure
+ //
+ CM3218DataLightVisibleGetRaw(psInst, &ui16Light);
+
+ //
+ // Get the floating point values for sensitivity
+ //
+ fSensitivity = g_pfSensitivityLookup[psInst->ui8IntTime];
+
+ //
+ // Calculate light reading in lux.
+ //
+ *pfVisibleLight = ((float)ui16Light) * fSensitivity;
+}
+
+//*****************************************************************************
+//
+// Close the Doxygen group.
+//! @}
+//
+//*****************************************************************************
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