/**************************************************************************** * * Copyright (c) 2021-2023 PX4 Development Team. 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 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 PX4 nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER 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. * ****************************************************************************/ /** * @file sht3x.cpp * * I2C driver for temperature/humidity sensor SHT3x by senserion * * @author Roman Dvorak * */ #include "sht3x.h" SHT3X::SHT3X(const I2CSPIDriverConfig &config) : I2C(config), ModuleParams(nullptr), I2CSPIDriver(config) { } uint8_t SHT3X::calc_crc(uint8_t data[2]) { uint8_t crc = 0xFF; for (int i = 0; i < 2; i++) { crc ^= data[i]; for (uint8_t bit = 8; bit > 0; --bit) { if (crc & 0x80) { crc = (crc << 1) ^ 0x31u; } else { crc = (crc << 1); } } } return crc; } int SHT3X::set_pointer(uint16_t command) { if (_last_command != command) { uint8_t cmd[2]; cmd[0] = static_cast(command >> 8); cmd[1] = static_cast(command & 0xff); _last_command = command; return transfer(&cmd[0], 2, nullptr, 0); } else { return 0; } } int SHT3X::read_data(uint16_t command, uint8_t *data_ptr, uint8_t length) { set_pointer(command); uint8_t raw_data[length]; transfer(nullptr, 0, &raw_data[0], length); uint8_t crc_err = 0; for (int i = 0; i < length / 3; ++i) { uint8_t crc_data[2] = {raw_data[i * 3], raw_data[i * 3 + 1]}; if (raw_data[i * 3 + 2] != calc_crc(crc_data)) { crc_err ++; } *(data_ptr + i * 2) = raw_data[i * 3]; *(data_ptr + i * 2 + 1) = raw_data[i * 3 + 1]; } return crc_err; } int SHT3X::write_data(uint16_t command, uint8_t buffer[], uint8_t length) { _last_command = command; uint8_t cmd[2 + 3 * length / 2]; cmd[0] = static_cast(command >> 8); cmd[1] = static_cast(command & 0xff); for (int i = 0; i < length / 2; ++i) { cmd[2 + 3 * i] = buffer[2 * i]; cmd[2 + 3 * i + 1] = buffer[2 * i + 1]; uint8_t crc_data[2] = {buffer[2 * i], buffer[2 * i + 1]}; cmd[2 + 3 * i + 2] = calc_crc(crc_data); } return transfer(&cmd[0], sizeof(cmd), nullptr, 0); } void SHT3X::sensor_compouse_msg(bool send) { uint8_t data[4]; int error = read_data(SHT3x_CMD_FETCH_DATA, &data[0], 6); if (error == PX4_OK) { measurement_time = hrt_absolute_time(); measurement_index ++; measured_temperature = (float) 175 * (data[0] << 8 | data[1]) / 65535 - 45; measured_humidity = (float) 100 * (data[2] << 8 | data[3]) / 65535; if (send) { sensor_hygrometer_s msg{}; msg.timestamp = hrt_absolute_time(); msg.timestamp_sample = measurement_time; msg.temperature = measured_temperature; msg.humidity = measured_humidity; msg.device_id = _sht_info.serial_number; _sensor_hygrometer_pub.publish(msg); } } } int SHT3X::probe() { uint8_t type[2]; uint8_t nvalid; nvalid = read_data(SHT3X_CMD_READ_STATUS, &type[0], 3); return (!(nvalid == PX4_OK)); // 0 means I can see sensor } int SHT3X::init() { if (I2C::init() != PX4_OK) { return PX4_ERROR; } _sensor_hygrometer_pub.advertise(); ScheduleOnInterval(50000); return PX4_OK; } int SHT3X::init_sensor() { set_pointer(SHT3X_CMD_CLEAR_STATUS); px4_usleep(2000); // Get sensor serial number uint8_t serial[4]; read_data(SHT3x_CMD_READ_SN, &serial[0], 6); _sht_info.serial_number = ((uint32_t)serial[0] << 24 | (uint32_t)serial[1] << 16 | (uint32_t)serial[2] << 8 | (uint32_t)serial[3]); set_pointer(SHT3x_CMD_PERIODIC_2HZ_MEDIUM); px4_usleep(2000); probe(); PX4_INFO("Connected to SHT3x sensor, SN: %ld", _sht_info.serial_number); // Modify ALERT range values to minimalize ALERT led heating. // def temp(t): // return ((t+45)*(2**16-1))/175 // def hum(h): // return (h/100)*(2**16-1) // // hex((int(hum(80))>>9<<9) | (int(temp(60))>>7)) uint8_t sh[] {0xff, 0xe2}; uint8_t ch[] {0xfb, 0xdc}; uint8_t sl[] {0x00, 0x0e}; uint8_t cl[] {0x04, 0x14}; write_data(SHT3x_CMD_ALERT_W_SET_HIGH, sh, 2); // 100%, 120C write_data(SHT3x_CMD_ALERT_W_CLEAR_HIGH, ch, 2); // 98%, 118C write_data(SHT3x_CMD_ALERT_W_SET_LOW, sl, 2); // 0%, -40C write_data(SHT3x_CMD_ALERT_W_CLEAR_LOW, cl, 2); // 2%, -38C return PX4_OK; } void SHT3X::RunImpl() { switch (_state) { case sht3x_state::INIT: probe(); init_sensor(); _state = sht3x_state::MEASUREMENT; break; case sht3x_state::MEASUREMENT: if ((hrt_absolute_time() - measurement_time) > 200000) { sensor_compouse_msg(1); } if ((hrt_absolute_time() - measurement_time) > 3000000) { _state = sht3x_state::ERROR_READOUT; } break; case sht3x_state::ERROR_GENERAL: case sht3x_state::ERROR_READOUT: { if (_last_state != _state) { PX4_INFO("I cant get new data. The sensor may be disconnected."); } if (probe() == PX4_OK) { _state = sht3x_state::INIT; } } break; } if (_last_state != _state) { _time_in_state = hrt_absolute_time(); _last_state = _state; } } void SHT3X::custom_method(const BusCLIArguments &cli) { switch (cli.custom1) { case 1: { PX4_INFO("Last measured values (%.3fs ago, #%d)", (double)(hrt_absolute_time() - measurement_time) / 1000000.0, measurement_index); PX4_INFO("Temp: %.3f, Hum: %.3f", (double)measured_temperature, (double)measured_humidity); } break; case 2: { _state = sht3x_state::INIT; } break; } } void SHT3X::print_status() { PX4_INFO("SHT3X sensor"); I2CSPIDriverBase::print_status(); PX4_INFO("SN: %ld", _sht_info.serial_number); PX4_INFO("Status: %s", sht_state_names[_state]); } void SHT3X::print_usage() { PRINT_MODULE_DESCRIPTION( R"DESCR_STR( ### Description SHT3x Temperature and Humidity Sensor Driver by Senserion. ### Examples CLI usage example: $ sht3x start -X Start the sensor driver on the external bus $ sht3x status Print driver status $ sht3x values Print last measured values $ sht3x reset Reinitialize senzor, reset flags )DESCR_STR"); PRINT_MODULE_USAGE_NAME("sht3x", "driver"); PRINT_MODULE_USAGE_COMMAND("start"); PRINT_MODULE_USAGE_PARAMS_I2C_SPI_DRIVER(true, false); PRINT_MODULE_USAGE_PARAMS_I2C_ADDRESS(0x44); PRINT_MODULE_USAGE_PARAMS_I2C_KEEP_RUNNING_FLAG(); PRINT_MODULE_USAGE_DEFAULT_COMMANDS(); PRINT_MODULE_USAGE_COMMAND_DESCR("values", "Print actual data"); PRINT_MODULE_USAGE_COMMAND_DESCR("reset", "Reinitialize sensor"); } int sht3x_main(int argc, char *argv[]) { using ThisDriver = SHT3X; BusCLIArguments cli{true, false}; cli.default_i2c_frequency = 400000; cli.i2c_address = 0x44; cli.support_keep_running = true; const char *verb = cli.parseDefaultArguments(argc, argv); if (!verb) { ThisDriver::print_usage(); return -1; } BusInstanceIterator iterator(MODULE_NAME, cli, DRV_HYGRO_DEVTYPE_SHT3X); if (!strcmp(verb, "start")) { return ThisDriver::module_start(cli, iterator); } if (!strcmp(verb, "stop")) { return ThisDriver::module_stop(iterator); } if (!strcmp(verb, "status")) { return ThisDriver::module_status(iterator); } if (!strcmp(verb, "values")) { cli.custom1 = 1; return ThisDriver::module_custom_method(cli, iterator, false); } if (!strcmp(verb, "reset")) { cli.custom1 = 2; return ThisDriver::module_custom_method(cli, iterator, false); } ThisDriver::print_usage(); return -1; }