/** * Copyright (c) 2012 - 2019, Nordic Semiconductor ASA * * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form, except as embedded into a Nordic * Semiconductor ASA integrated circuit in a product or a software update for * such product, must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other * materials provided with the distribution. * * 3. Neither the name of Nordic Semiconductor ASA nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * 4. This software, with or without modification, must only be used with a * Nordic Semiconductor ASA integrated circuit. * * 5. Any software provided in binary form under this license must not be reverse * engineered, decompiled, modified and/or disassembled. * * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #include "ds1624.h" #include "twi_master.h" #include "nrf_delay.h" /*lint ++flb "Enter library region" */ #define DS1634_BASE_ADDRESS 0x90 //!< 4 MSBs of the DS1624 TWI address #define DS1624_ONESHOT_MODE 0x01 //!< Bit in configuration register for 1-shot mode #define DS1624_CONVERSION_DONE 0x80 //!< Bit in configuration register to indicate completed temperature conversion static uint8_t m_device_address; //!< Device address in bits [7:1] const uint8_t command_access_memory = 0x17; //!< Reads or writes to 256-byte EEPROM memory const uint8_t command_access_config = 0xAC; //!< Reads or writes configuration data to configuration register const uint8_t command_read_temp = 0xAA; //!< Reads last converted temperature value from temperature register const uint8_t command_start_convert_temp = 0xEE; //!< Initiates temperature conversion. const uint8_t command_stop_convert_temp = 0x22; //!< Halts temperature conversion. /** * @brief Function for reading the current configuration of the sensor. * * @return uint8_t Zero if communication with the sensor failed. Contents (always non-zero) of configuration register (@ref DS1624_ONESHOT_MODE and @ref DS1624_CONVERSION_DONE) if communication succeeded. */ static uint8_t ds1624_config_read(void) { uint8_t config = 0; // Write: command protocol if (twi_master_transfer(m_device_address, (uint8_t*)&command_access_config, 1, TWI_DONT_ISSUE_STOP)) { if (twi_master_transfer(m_device_address | TWI_READ_BIT, &config, 1, TWI_ISSUE_STOP)) // Read: current configuration { // Read succeeded, configuration stored to variable "config" } else { // Read failed config = 0; } } return config; } bool ds1624_init(uint8_t device_address) { bool transfer_succeeded = true; m_device_address = DS1634_BASE_ADDRESS + (uint8_t)(device_address << 1); uint8_t config = ds1624_config_read(); if (config != 0) { // Configure DS1624 for 1SHOT mode if not done so already. if (!(config & DS1624_ONESHOT_MODE)) { uint8_t data_buffer[2]; data_buffer[0] = command_access_config; data_buffer[1] = DS1624_ONESHOT_MODE; transfer_succeeded &= twi_master_transfer(m_device_address, data_buffer, 2, TWI_ISSUE_STOP); } } else { transfer_succeeded = false; } return transfer_succeeded; } bool ds1624_start_temp_conversion(void) { return twi_master_transfer(m_device_address, (uint8_t*)&command_start_convert_temp, 1, TWI_ISSUE_STOP); } bool ds1624_is_temp_conversion_done(void) { uint8_t config = ds1624_config_read(); if (config & DS1624_CONVERSION_DONE) { return true; } else { return false; } } bool ds1624_temp_read(int8_t * temperature_in_celcius, int8_t * temperature_fraction) { bool transfer_succeeded = false; // Write: Begin read temperature command if (twi_master_transfer(m_device_address, (uint8_t*)&command_read_temp, 1, TWI_DONT_ISSUE_STOP)) { uint8_t data_buffer[2]; // Read: 2 temperature bytes to data_buffer if (twi_master_transfer(m_device_address | TWI_READ_BIT, data_buffer, 2, TWI_ISSUE_STOP)) { *temperature_in_celcius = (int8_t)data_buffer[0]; *temperature_fraction = (int8_t)data_buffer[1]; transfer_succeeded = true; } } return transfer_succeeded; } /*lint --flb "Leave library region" */