/* * Author: Jon Trulson * Copyright (c) 2016-2017 Intel Corporation. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #pragma once #include #include #include #include #include #include #include #include #include #define DS18B20_DEFAULT_UART 0 namespace upm { /** * @brief DS18B20 1-Wire Temperature Sensor * @defgroup ds18b20 libupm-ds18b20 * @ingroup maxim uart */ /** * @library ds18b20 * @sensor ds18b20 * @comname DS18B20 1-Wire Temperature Sensor * @type uart * @man maxim * @con uart * @web https://www.sparkfun.com/products/11050 * * @brief API for the DS18B20 1-Wire Temperature Sensor * * This driver supports, and was tested with, a DS18B20 with * external power. * * Multiple DS18B20 devices can be connected to this bus. This * module will identify all such devices connected, and allow you * to access them using an index starting at 0. * * Parasitic power is not currently supported due * to the very tight 10us limit on switching a GPIO properly to * supply power during certain operations. For this reason, you * should use external power for your sensors. * * Setting the alarm values (Tl, Th) is also not supported, since * this is only useful when doing a 1-wire device search looking * for devices in an alarm state, a capability not yet supported * in MRAA. In reality, this is trivial to handle yourself in * your application. * * This device requires the use of a TTL level UART (specifically * through the UartOW MRAA context class) to provide access to a * Dallas 1-wire bus. It is important to realize that the UART is * only being used to provide an interface to devices on a Dallas * 1-wire compliant bus. * * A circuit like the following should be used for the UART * interface (ASCII schematic - best viewed in a fixed monospace * font): * * -| * U| (D1) * A| TX---|<--+ * R| | * T| RX-------o--------o >to 1-wire data bus * -| * * * Vcc * | * o------------+ * | | * R1 | * | o(+) * >1-wire------o--------o[DS18B20] * o(-) * | * GND * * D1 = 1N4148 * R1 = 4.7K * * The cathode of D1 is connected to the UART TX. * * @snippet ds18b20.cxx Interesting */ class DS18B20 { public: /** * DS18B20 object constructor * * This method will search the 1-wire bus and store information on * each device detected on the bus. If no devices are found, an * exception is thrown. Once this function completes * successfully, you can use devicesFound() to determine how many * devices were detected. * * @param uart Default UART to use (0 or 1). Default is 0. */ DS18B20(int uart=DS18B20_DEFAULT_UART); /** * DS18B20 object destructor */ ~DS18B20(); /** * @deprecated This method is deprecated. It's functionality is * handled in the constructor now. */ void init(); /** * Update our stored temperature for a device. This method must * be called prior to getTemperature(). * * @param index The device index to access (starts at 0). Specify * -1 to query all detected devices. Default: -1 */ void update(int index=-1); /** * Get the current temperature. update() must have been called * prior to calling this method. * * @param index The device index to access (starts at 0). * @param fahrenheit true to return the temperature in degrees * fahrenheit, false to return the temperature in degrees celsius. * The default is false (degrees Celsius). * @return The last temperature reading in Celsius or Fahrenheit */ float getTemperature(unsigned int index, bool fahrenheit=false); /** * Set the device resolution for a device. These devices support * 9, 10, 11, and 12 bits of resolution, with the default from the * factory at 12 bits. * * @param index The device index to access (starts at 0). * @param res One of the RESOLUTIONS_T values */ void setResolution(unsigned int index, DS18B20_RESOLUTIONS_T res); /** * Copy the device's scratchpad memory to the EEPROM. This * includes the configuration byte (resolution). * * @param index The device index to access (starts at 0). */ void copyScratchPad(unsigned int index); /** * Copy the device's EEPROM memory to the scratchpad. This method * will return when the copy completes. This operation is * performed by the device automatically on power up, so it is * rarely needed. * * @param index The device index to access (starts at 0). */ void recallEEPROM(unsigned int index); /** * This method will return the number of DS18B20 devices that were * found on the bus by init(). * * @return number of DS18B20's that were found on the bus */ int devicesFound() { return ds18b20_devices_found(m_ds18b20); } /** * Return an 8 byte string representing the unique device ID * (1-wire romcode) for a given device index. * * @param index The device index to access (starts at 0). * @return 8 byte string representing the 1-wire device's unique * romcode. */ std::string getId(unsigned int index); protected: ds18b20_context m_ds18b20; private: }; }