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121 lines
3.1 KiB
121 lines
3.1 KiB
/* |
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* Copyright (C) 2014 PHYTEC Messtechnik GmbH |
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* 2017 Freie Universität Berlin |
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* |
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* This file is subject to the terms and conditions of the GNU Lesser |
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* General Public License v2.1. See the file LICENSE in the top level |
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* directory for more details. |
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* |
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*/ |
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/** |
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* @ingroup drivers_hdc1000 |
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* @{ |
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* |
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* @file |
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* @brief Driver for the TI HDC1000 Humidity and Temperature Sensor. |
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* |
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* @author Johann Fischer <j.fischer@phytec.de> |
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* @author Hauke Petersen <hauke.petersen@fu-berlin.de> |
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* |
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* @} |
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*/ |
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#include <string.h> |
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#include "assert.h" |
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#include "xtimer.h" |
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#include "periph/i2c.h" |
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#include "hdc1000.h" |
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#define ENABLE_DEBUG (0) |
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#include "debug.h" |
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#define I2C_SPEED I2C_SPEED_FAST |
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int hdc1000_init(hdc1000_t *dev, const hdc1000_params_t *params) |
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{ |
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uint8_t reg[2]; |
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uint16_t tmp; |
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/* write device descriptor */ |
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memcpy(&dev->p, params, sizeof(hdc1000_params_t)); |
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/* initialize the I2C bus */ |
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i2c_acquire(dev->p.i2c); |
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if (i2c_init_master(dev->p.i2c, I2C_SPEED) < 0) { |
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i2c_release(dev->p.i2c); |
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return HDC1000_NOBUS; |
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} |
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/* try if we can interact with the device by reading its manufacturer ID */ |
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if (i2c_read_regs(dev->p.i2c, dev->p.addr, |
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HDC1000_MANUFACTURER_ID, reg, 2) != 2) { |
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i2c_release(dev->p.i2c); |
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return HDC1000_NOBUS; |
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} |
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tmp = ((uint16_t)reg[0] << 8) | reg[1]; |
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if (tmp != HDC1000_MID_VALUE) { |
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i2c_release(dev->p.i2c); |
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return HDC1000_NODEV; |
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} |
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/* set resolution for both sensors and sequence mode */ |
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tmp = (HDC1000_SEQ_MOD | dev->p.res); |
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reg[0] = (tmp >> 8); |
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reg[1] = tmp; |
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if (i2c_write_regs(dev->p.i2c, dev->p.addr, HDC1000_CONFIG, reg, 2) != 2) { |
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i2c_release(dev->p.i2c); |
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return HDC1000_NOBUS; |
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} |
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i2c_release(dev->p.i2c); |
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/* all set */ |
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return HDC1000_OK; |
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} |
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void hdc1000_trigger_conversion(hdc1000_t *dev) |
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{ |
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assert(dev); |
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i2c_acquire(dev->p.i2c); |
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/* Trigger the measurements by executing a write access |
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* to the address 0x00 (HDC1000_TEMPERATURE). |
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* Conversion Time is 6.50ms for each value for 14 bit resolution. |
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*/ |
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i2c_write_byte(dev->p.i2c, dev->p.addr, HDC1000_TEMPERATURE); |
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i2c_release(dev->p.i2c); |
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} |
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void hdc1000_get_results(hdc1000_t *dev, int16_t *temp, int16_t *hum) |
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{ |
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assert(dev); |
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uint8_t buf[4]; |
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/* first we read the RAW results from the device */ |
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i2c_acquire(dev->p.i2c); |
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i2c_read_bytes(dev->p.i2c, dev->p.addr, buf, 4); |
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i2c_release(dev->p.i2c); |
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/* and finally we convert the values to their physical representation */ |
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if (temp) { |
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uint16_t traw = ((uint16_t)buf[0] << 8) | buf[1]; |
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*temp = (int16_t)((((int32_t)traw * 16500) >> 16) - 4000); |
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} |
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if (hum) { |
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uint16_t hraw = ((uint16_t)buf[2] << 8) | buf[3]; |
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*hum = (int16_t)(((int32_t)hraw * 10000) >> 16); |
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} |
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} |
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void hdc1000_read(hdc1000_t *dev, int16_t *temp, int16_t *hum) |
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{ |
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hdc1000_trigger_conversion(dev); |
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xtimer_usleep(HDC1000_CONVERSION_TIME); |
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hdc1000_get_results(dev, temp, hum); |
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}
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