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opt-3001-sensor.c
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1/*
2 * Copyright (c) 2014, Texas Instruments Incorporated - http://www.ti.com/
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the copyright holder nor the names of its
14 * contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
21 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
28 * OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30/*---------------------------------------------------------------------------*/
31/**
32 * \addtogroup sensortag-cc26xx-opt-sensor
33 * @{
34 *
35 * \file
36 * Driver for the Sensortag Opt3001 light sensor
37 */
38/*---------------------------------------------------------------------------*/
39#include "contiki.h"
40#include "lib/sensors.h"
41#include "opt-3001-sensor.h"
42#include "sys/ctimer.h"
43#include "ti-lib.h"
44#include "board-i2c.h"
45#include "sensor-common.h"
46
47#include <stdint.h>
48#include <stdbool.h>
49#include <string.h>
50#include <stdio.h>
51#include <math.h>
52/*---------------------------------------------------------------------------*/
53#define DEBUG 0
54#if DEBUG
55#define PRINTF(...) printf(__VA_ARGS__)
56#else
57#define PRINTF(...)
58#endif
59/*---------------------------------------------------------------------------*/
60/* Slave address */
61#define OPT3001_I2C_ADDRESS 0x45
62/*---------------------------------------------------------------------------*/
63/* Register addresses */
64#define REG_RESULT 0x00
65#define REG_CONFIGURATION 0x01
66#define REG_LOW_LIMIT 0x02
67#define REG_HIGH_LIMIT 0x03
68
69#define REG_MANUFACTURER_ID 0x7E
70#define REG_DEVICE_ID 0x7F
71/*---------------------------------------------------------------------------*/
72/*
73 * Configuration Register Bits and Masks.
74 * We use uint16_t to read from / write to registers, meaning that the
75 * register's MSB is the variable's LSB.
76 */
77#define CONFIG_RN 0x00F0 /* [15..12] Range Number */
78#define CONFIG_CT 0x0008 /* [11] Conversion Time */
79#define CONFIG_M 0x0006 /* [10..9] Mode of Conversion */
80#define CONFIG_OVF 0x0001 /* [8] Overflow */
81#define CONFIG_CRF 0x8000 /* [7] Conversion Ready Field */
82#define CONFIG_FH 0x4000 /* [6] Flag High */
83#define CONFIG_FL 0x2000 /* [5] Flag Low */
84#define CONFIG_L 0x1000 /* [4] Latch */
85#define CONFIG_POL 0x0800 /* [3] Polarity */
86#define CONFIG_ME 0x0400 /* [2] Mask Exponent */
87#define CONFIG_FC 0x0300 /* [1..0] Fault Count */
88
89/* Possible Values for CT */
90#define CONFIG_CT_100 0x0000
91#define CONFIG_CT_800 CONFIG_CT
92
93/* Possible Values for M */
94#define CONFIG_M_CONTI 0x0004
95#define CONFIG_M_SINGLE 0x0002
96#define CONFIG_M_SHUTDOWN 0x0000
97
98/* Reset Value for the register 0xC810. All zeros except: */
99#define CONFIG_RN_RESET 0x00C0
100#define CONFIG_CT_RESET CONFIG_CT_800
101#define CONFIG_L_RESET 0x1000
102#define CONFIG_DEFAULTS (CONFIG_RN_RESET | CONFIG_CT_100 | CONFIG_L_RESET)
103
104/* Enable / Disable */
105#define CONFIG_ENABLE_CONTINUOUS (CONFIG_M_CONTI | CONFIG_DEFAULTS)
106#define CONFIG_ENABLE_SINGLE_SHOT (CONFIG_M_SINGLE | CONFIG_DEFAULTS)
107#define CONFIG_DISABLE CONFIG_DEFAULTS
108/*---------------------------------------------------------------------------*/
109/* Register length */
110#define REGISTER_LENGTH 2
111/*---------------------------------------------------------------------------*/
112/* Sensor data size */
113#define DATA_LENGTH 2
114/*---------------------------------------------------------------------------*/
115/*
116 * SENSOR_STATE_SLEEPING and SENSOR_STATE_ACTIVE are mutually exclusive.
117 * SENSOR_STATE_DATA_READY can be ORd with both of the above. For example the
118 * sensor may be sleeping but with a conversion ready to read out.
119 */
120#define SENSOR_STATE_SLEEPING 0
121#define SENSOR_STATE_ACTIVE 1
122#define SENSOR_STATE_DATA_READY 2
123
124static int state = SENSOR_STATE_SLEEPING;
125/*---------------------------------------------------------------------------*/
126/* Wait SENSOR_STARTUP_DELAY for the sensor to be ready - 125ms */
127#define SENSOR_STARTUP_DELAY (CLOCK_SECOND >> 3)
128
129static struct ctimer startup_timer;
130/*---------------------------------------------------------------------------*/
131/**
132 * \brief Select the sensor on the I2C bus
133 */
134static void
136{
137 /* Select slave and set clock rate */
138 board_i2c_select(BOARD_I2C_INTERFACE_0, OPT3001_I2C_ADDRESS);
139}
140/*---------------------------------------------------------------------------*/
141static void
142notify_ready(void *not_used)
143{
144 /*
145 * Depending on the CONFIGURATION.CONVERSION_TIME bits, a conversion will
146 * take either 100 or 800 ms. Here we inspect the CONVERSION_READY bit and
147 * if the reading is ready we notify, otherwise we just reschedule ourselves
148 */
149 uint16_t val;
150
152
153 sensor_common_read_reg(REG_CONFIGURATION, (uint8_t *)&val, REGISTER_LENGTH);
154
155 if(val & CONFIG_CRF) {
156 sensors_changed(&opt_3001_sensor);
157 state = SENSOR_STATE_DATA_READY;
158 } else {
159 ctimer_set(&startup_timer, SENSOR_STARTUP_DELAY, notify_ready, NULL);
160 }
161}
162/*---------------------------------------------------------------------------*/
163/**
164 * \brief Turn the sensor on/off
165 * \param enable TRUE: on, FALSE: off
166 */
167static void
168enable_sensor(bool enable)
169{
170 uint16_t val;
171 uint16_t had_data_ready = state & SENSOR_STATE_DATA_READY;
172
174
175 if(enable) {
176 val = CONFIG_ENABLE_SINGLE_SHOT;
177
178 /* Writing CONFIG_ENABLE_SINGLE_SHOT to M bits will clear CRF bits */
179 state = SENSOR_STATE_ACTIVE;
180 } else {
181 val = CONFIG_DISABLE;
182
183 /* Writing CONFIG_DISABLE to M bits will not clear CRF bits */
184 state = SENSOR_STATE_SLEEPING | had_data_ready;
185 }
186
187 sensor_common_write_reg(REG_CONFIGURATION, (uint8_t *)&val, REGISTER_LENGTH);
188}
189/*---------------------------------------------------------------------------*/
190/**
191 * \brief Read the result register
192 * \param raw_data Pointer to a buffer to store the reading
193 * \return TRUE if valid data
194 */
195static bool
197{
198 bool success;
199 uint16_t val;
200
201 if((state & SENSOR_STATE_DATA_READY) != SENSOR_STATE_DATA_READY) {
202 return false;
203 }
204
206
207 success = sensor_common_read_reg(REG_CONFIGURATION, (uint8_t *)&val,
208 REGISTER_LENGTH);
209
210 if(success) {
211 success = sensor_common_read_reg(REG_RESULT, (uint8_t *)&val, DATA_LENGTH);
212 }
213
214 if(success) {
215 /* Swap bytes */
216 *raw_data = (val << 8) | (val >> 8 & 0xFF);
217 } else {
219 }
220
221 return success;
222}
223/*---------------------------------------------------------------------------*/
224/**
225 * \brief Convert raw data to a value in lux
226 * \param raw_data data Pointer to a buffer with a raw sensor reading
227 * \return Converted value (lux)
228 */
229static float
231{
232 uint16_t e, m;
233
234 m = raw_data & 0x0FFF;
235 e = (raw_data & 0xF000) >> 12;
236
237 return m * (0.01 * exp2(e));
238}
239/*---------------------------------------------------------------------------*/
240/**
241 * \brief Returns a reading from the sensor
242 * \param type Ignored
243 * \return Illuminance in centilux
244 */
245static int
246value(int type)
247{
248 int rv;
250 float converted_val;
251
252 rv = read_data(&raw_val);
253
254 if(rv == false) {
255 return CC26XX_SENSOR_READING_ERROR;
256 }
257
259 PRINTF("OPT: %04X r=%d (centilux)\n", raw_val,
260 (int)(converted_val * 100));
261
262 rv = (int)(converted_val * 100);
263
264 return rv;
265}
266/*---------------------------------------------------------------------------*/
267/**
268 * \brief Configuration function for the OPT3001 sensor.
269 *
270 * \param type Activate, enable or disable the sensor. See below
271 * \param enable
272 *
273 * When type == SENSORS_HW_INIT we turn on the hardware
274 * When type == SENSORS_ACTIVE and enable==1 we enable the sensor
275 * When type == SENSORS_ACTIVE and enable==0 we disable the sensor
276 */
277static int
278configure(int type, int enable)
279{
280 int rv = 0;
281
282 switch(type) {
283 case SENSORS_HW_INIT:
284 /*
285 * Device reset won't reset the sensor, so we put it to sleep here
286 * explicitly
287 */
288 enable_sensor(0);
289 rv = 0;
290 break;
291 case SENSORS_ACTIVE:
292 if(enable) {
293 enable_sensor(1);
294 ctimer_set(&startup_timer, SENSOR_STARTUP_DELAY, notify_ready, NULL);
295 rv = 1;
296 } else {
297 ctimer_stop(&startup_timer);
298 enable_sensor(0);
299 rv = 0;
300 }
301 break;
302 default:
303 break;
304 }
305 return rv;
306}
307/*---------------------------------------------------------------------------*/
308/**
309 * \brief Returns the status of the sensor
310 * \param type ignored
311 * \return The state of the sensor SENSOR_STATE_xyz
312 */
313static int
314status(int type)
315{
316 switch(type) {
317 case SENSORS_ACTIVE:
318 case SENSORS_READY:
319 default:
320 break;
321 }
322 return state;
323}
324/*---------------------------------------------------------------------------*/
325SENSORS_SENSOR(opt_3001_sensor, "OPT3001", value, configure, status);
326/*---------------------------------------------------------------------------*/
327/** @} */
Header file for the Sensortag I2C Driver.
Header file for the Sensortag Opt3001 light sensor.
Header file for the callback timer.
void ctimer_stop(struct ctimer *c)
Stop a pending callback timer.
Definition ctimer.c:138
static void ctimer_set(struct ctimer *c, clock_time_t t, void(*f)(void *), void *ptr)
Set a callback timer.
Definition ctimer.h:137
static bool read_data()
Take readings from the sensor.
void board_i2c_select(uint8_t new_interface, uint8_t address)
Select an I2C slave.
Definition board-i2c.c:310
static int value(int type)
Returns a reading from the sensor.
static float convert(uint16_t raw_data)
Convert raw data to a value in lux.
static int status(int type)
Returns the status of the sensor.
static void enable_sensor(bool enable)
Turn the sensor on/off.
static void select_on_bus(void)
Select the sensor on the I2C bus.
static int configure(int type, int enable)
Configuration function for the OPT3001 sensor.
void sensor_common_set_error_data(uint8_t *buf, uint8_t len)
Fill a result buffer with dummy error data.
bool sensor_common_read_reg(uint8_t addr, uint8_t *buf, uint8_t len)
Reads a sensor's register over I2C.
bool sensor_common_write_reg(uint8_t addr, uint8_t *buf, uint8_t len)
Write to a sensor's register over I2C.
Header file for the Sensortag Common sensor utilities.
Header file with macros which rename TI CC26xxware functions.