Diff: si7210.h

Revision:

2:d85076c18c80

Parent:

1:8cb452601311

Child:

3:beca2e65b1b0

--- a/si7210.h	Thu Sep 14 00:07:17 2017 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,256 +0,0 @@
-/* mbed Microcontroller Library
- * Copyright (c) 2017 AT&T, IIoT Foundry, Plano, TX, USA
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/** \addtogroup drivers */
-
-/** Support for Silicon Labs SI7210: Magnetic field and temperature sensor
- *
- * Example:
- * @code
- *
- * #include "mbed.h"
- * #include "SI7210.h"
- *
- * I2C          i2c(I2C_SDA, I2C_SCL);
- * SI7210<I2C>  si7210(&i2c, SI7210_BASE_ADDR_7BIT);
- *
- * int main() {
- *     si7210_measurements_t  data;
- *     bool                   ok;
- *
- *     ok = si7210.enable() &&
- *          si7210.read(&data) &&
- *          si7210.disable();
- *           
- *     if (ok) {
-            printf("Mag T: %f\r\n", data.mag_T);
-            printf("temp C/F: %f/%f\r\n", data.temp_C, data.temp_C * 9 / 5 + 32);
- *     } else {
- *         printf("si7210 error!\r\n");
- *     }
- * }
- * @endcode
- * @ingroup drivers
- */
-
-#pragma once
-
-#define ARAUTOINC__ARAUTOINC_MASK       0x01
-#define OTP_CTRL__OPT_BUSY_MASK         0x01
-#define OTP_CTRL__OPT_READ_EN_MASK      0x02
-#define POWER_CTRL__SLEEP_MASK          0x01
-#define POWER_CTRL__STOP_MASK           0x02
-#define POWER_CTRL__ONEBURST_MASK       0x04
-#define POWER_CTRL__USESTORE_MASK       0x08
-#define POWER_CTRL__MEAS_MASK           0x80
-#define DSPSIGSEL__MAG_VAL_SEL          0
-#define DSPSIGSEL__TEMP_VAL_SEL         1
-
-/** I2C registers for Si72xx */
-#define SI72XX_OTP_TEMP_OFFSET  0x1D
-#define SI72XX_OTP_TEMP_GAIN    0x1E
-#define SI72XX_HREVID           0xC0
-#define SI72XX_DSPSIGM          0xC1
-#define SI72XX_DSPSIGL          0xC2
-#define SI72XX_DSPSIGSEL        0xC3
-#define SI72XX_POWER_CTRL       0xC4
-#define SI72XX_ARAUTOINC        0xC5
-#define SI72XX_CTRL1            0xC6
-#define SI72XX_CTRL2            0xC7
-#define SI72XX_SLTIME           0xC8
-#define SI72XX_CTRL3            0xC9
-#define SI72XX_A0               0xCA
-#define SI72XX_A1               0xCB
-#define SI72XX_A2               0xCC
-#define SI72XX_CTRL4            0xCD
-#define SI72XX_A3               0xCE
-#define SI72XX_A4               0xCF
-#define SI72XX_A5               0xD0
-#define SI72XX_OTP_ADDR         0xE1
-#define SI72XX_OTP_DATA         0xE2
-#define SI72XX_OTP_CTRL         0xE3
-#define SI72XX_TM_FG            0xE4
-
-#define SI7210_BASE_ADDR_7BIT   0x30
-
-typedef struct {
-    float       mag_T;
-    float       temp_C;
-} si7210_measurements_t;
-
-template <class T>
-class SI7210 {
- public:
-    /**
-    * Constructor
-    *
-    * @param i2c I2C class servicing the strip
-    */
-    SI7210(T * i2c, uint8_t addr_7bit) : _i2c(i2c) {
-        _isTempOffsetAndGainValid = false;
-        _enabled = false;
-        _addr_8bit = ((addr_7bit & 0x3) + SI7210_BASE_ADDR_7BIT) << 1;
-    }
-
-    /**
-    * Activate the sensor (wake if sleeping).
-    *
-    * @returns true (success) or false (failure)
-    */
-    bool enable(void) {
-        bool ok = _i2c_transfer(_addr_8bit, NULL, 0, 0);
-        if (ok)
-            _enabled = true;
-        return ok;
-    }
-
-    /**
-    * Deactivate the sensor (puts it to sleep)
-    *
-    * @returns true (success) or false (failure)
-    */
-    bool disable(void) {
-        bool ok = _write_reg(SI72XX_POWER_CTRL, POWER_CTRL__SLEEP_MASK);
-        if (ok)
-            _enabled = ok;
-        return ok;
-    }
-
-    /**
-    * Read temperature and humidity
-    *
-    * @param data points to struct to store measurements in.  Stucture is
-    *      valid only when function returns success indication.
-    *
-    * @returns true (success) or false (failure)
-    */
-    bool read(si7210_measurements_t * data) {
-        uint16_t    magRaw;
-        uint16_t    tempRaw;
-        
-        bool ok = _write_reg(SI72XX_ARAUTOINC, ARAUTOINC__ARAUTOINC_MASK)
-               && _write_reg(SI72XX_DSPSIGSEL, DSPSIGSEL__MAG_VAL_SEL)      //capture mag field measurement
-               && _write_reg(SI72XX_POWER_CTRL, POWER_CTRL__ONEBURST_MASK)
-               && _read_regs(SI72XX_DSPSIGM, 2, &magRaw)
-               && _write_reg(SI72XX_DSPSIGSEL, DSPSIGSEL__TEMP_VAL_SEL)     //capture temp measurement
-               && _write_reg(SI72XX_POWER_CTRL, POWER_CTRL__ONEBURST_MASK)
-               && _read_regs(SI72XX_DSPSIGM, 2, &tempRaw);
-
-        if (ok && !_isTempOffsetAndGainValid) {
-            char otpTempOffset;
-            char otpTempGain;
-            
-            ok = _read_otp(SI72XX_OTP_TEMP_OFFSET, &otpTempOffset)
-              && _read_otp(SI72XX_OTP_TEMP_GAIN, &otpTempGain);
-            if (ok) {
-                _tempOffset = (float)otpTempOffset / 16;
-                _tempGain = 1 + (float)otpTempGain / 2048;
-                _isTempOffsetAndGainValid = true;
-            }
-        }
-        
-        if (ok) {
-            magRaw = ((magRaw >> 8) & 0xff) + ((magRaw & 0xff) << 8);
-            tempRaw = ((tempRaw >> 8) & 0xff) + ((tempRaw & 0xff) << 8);
-            ok = (magRaw & 0x8000) && (tempRaw & 0x8000);
-            data->mag_T = (float)(magRaw - 0xC000) * 0.00125F;
-            data->temp_C = (float)((tempRaw & ~0x8000) >> 3);
-            data->temp_C = _tempGain * (-3.83e-6F * data->temp_C * data->temp_C + 0.16094F * data->temp_C - 279.80F - 0.222F * 3.0F) + _tempOffset;
-        }
-        
-        return ok;
-    }
-
- protected:
-
-    /**
-    * I2C read/write helper function
-    *
-    * @param address is the register to read/write
-    * @param buff holds the data to write and recieves the data to read
-    * @param writeSize is the number of bytes to write to register
-    * @param readSize is the number of bytes to retrieve from device
-    *
-    * @returns true (success) or false (failure)
-    */
-    bool _i2c_transfer(int address, void * buff, size_t writeSize, size_t readSize) {
-        bool ok;
-        bool expect_response = (readSize != 0);
-    
-        ok = !_i2c->write(address, (char*)buff, writeSize, expect_response);
-        if (ok && expect_response)
-            ok = !_i2c->read(address, (char*)buff, readSize);
-    
-        return ok;
-    }
-
-    /**
-    * Write to an I2C register
-    *
-    * @param reg sensor register to write
-    * @param val value to write
-    *
-    * @returns true (success) or false (failure)
-    */
-    bool _write_reg(char reg, char val) {
-        char out[2] = {reg, val};
-        return 0 == _i2c->write(_addr_8bit, out, 2);
-    }
-
-    /**
-    * Read multiple sensor registers
-    *
-    * @param start_reg first sensor register to be read
-    * @param count number of registers to be read
-    * @param buff pointer to buffer where to store the register values
-    *
-    * @returns true (success) or false (failure)
-    */
-    bool _read_regs(char start_reg, char count, void * buff) {
-        bool ok;
-        ok = (0 == _i2c->write(_addr_8bit, &start_reg, 1, true))
-             && (0 == _i2c->read(_addr_8bit, (char *)buff, count));
-        return ok;
-    }
-
-    /**
-    * Read sensor OTP
-    *
-    * @param otpAddr OTP address to be read
-    * @param *data where to store the OTP data
-    *
-    * @returns true (success) or false (failure)
-    */
-    bool _read_otp(uint8_t otpAddr, void *data) {
-        uint8_t optCtrl;
-        
-        bool ok = _read_regs(SI72XX_OTP_CTRL, 1, &optCtrl)
-               && !(optCtrl & OTP_CTRL__OPT_BUSY_MASK)
-               && _write_reg(SI72XX_OTP_ADDR, otpAddr)
-               && _write_reg(SI72XX_OTP_CTRL, OTP_CTRL__OPT_READ_EN_MASK)
-               && _read_regs(SI72XX_OTP_DATA, 1, data);
-        
-        return ok;
-    }
-
-    bool    _isTempOffsetAndGainValid;
-    float   _tempOffset;
-    float   _tempGain;
-    bool    _enabled;
-    int     _addr_8bit;
-    T      *_i2c;
-};
-