/* * Author: Jon Trulson * Copyright (c) 2016 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 #ifdef __cplusplus extern "C" { #endif /** * @file otp538u.h * @library otp538u * @brief C API for the OTP538U IR Temperature Sensor * * @include otp538u.c */ /** * device context */ typedef struct _otp538u_context { mraa_aio_context aioA; mraa_aio_context aioO; bool debug; float internalVRef; float aref; int vResistance; float offsetVoltage; int adcResolution; } *otp538u_context; /** * OTP538U constructor * * @param pinA Analog pin to use for the ambient temperature * @param pinO Analog pin to use for the object temperature * @param aref Analog reference voltage * @return intialized context, or NULL if error */ otp538u_context otp538u_init(int pinA, int pinO, float aref); /** * OTP538U destructor * * @param dev Device context */ void otp538u_close(otp538u_context dev); /** * Gets the ambient temperature in Celsius * * @param dev Device context * @param temp Ambient temperature * @return UPM status */ upm_result_t otp538u_get_ambient_temperature(const otp538u_context dev, float *temperature); /** * Gets the object temperature in Celsius * * @param dev Device context * @param temp Object temperature * @return UPM status */ upm_result_t otp538u_get_object_temperature(const otp538u_context dev, float *temperature); /** * Sets the offset voltage * * The Seeed Studio wiki gives an example of calibrating the sensor * and calculating the offset voltage to apply. Currently, the * default value is set, but you can use the function to set one * of your own. * * @param dev Device context * @param vOffset Desired offset voltage */ void otp538u_set_voltage_offset(const otp538u_context dev, float offset); /** * Sets the output resistance value * * The Seeed Studio wiki example uses a value of 2,000,000 in one of * the equations used to calculate voltage. The value is the * resistance of a resistor they use in the output stage of their * SIG2 output. This was 'decoded' by looking at the EAGLE* files * containing their schematics for this device. * * @param dev Device context * @param outResistance Value of the output resistor; default is 2M Ohm */ void otp538u_set_output_resistence(const otp538u_context dev, int resistance); /** * Sets the reference voltage of the internal Seeed Studio voltage * regulator on the sensor board. * * The Seeed Studio wiki example uses a value of 2.5 in one of the * equations used to calculate the resistance of the ambient * thermistor. The value is the voltage of an internal voltage * regulator used on the sensor board. This was 'decoded' by * looking at the EAGLE files containing their schematics for this * device. * * @param dev Device context * @param vref Reference voltage of the internal sensor; default * is 2.5 */ void otp538u_set_ivref(const otp538u_context dev, float vref); /** * Enable debugging output (linux platforms only). * * @param dev Device context * @param enable true to enable some debug output, false otherwise */ void otp538u_set_debug(const otp538u_context dev, bool enable); #ifdef __cplusplus } #endif