/* * Author: Nandkishor Sonar * Copyright (c) 2014 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 /** * @file * @brief Analog input/output * * AIO is the anlog input & output interface to libmraa. It is used to read or * set the voltage applied to an AIO pin. * * @snippet analogin_a0.c Interesting */ #ifdef __cplusplus extern "C" { #endif #include <stdio.h> #include <unistd.h> #include <stdint.h> #include "common.h" #include "gpio.h" /** * Opaque pointer definition to the internal struct _aio. This context refers * to one single AIO pin on the board. */ typedef struct _aio* mraa_aio_context; /** * Initialise an Analog input device, connected to the specified pin * * @param pin Channel number to read ADC inputs * @returns aio context or NULL */ mraa_aio_context mraa_aio_init(unsigned int pin); /** * Read the input voltage. By default mraa will shift * the raw value up or down to a 10 bit value. * * @param dev The AIO context * @returns The current input voltage. */ unsigned int mraa_aio_read(mraa_aio_context dev); /** * Read the input voltage and return it as a normalized float (0.0f-1.0f). * * @param dev The AIO context * @returns The current input voltage as a normalized float (0.0f-1.0f) */ float mraa_aio_read_float(mraa_aio_context dev); /** * Close the analog input context, this will free the memory for the context * * @param dev The AIO context * @return Result of operation */ mraa_result_t mraa_aio_close(mraa_aio_context dev); /** * Set the bit value which mraa will shift the raw reading * from the ADC to. I.e. 10bits * @param dev the analog input context * @param bits the bits the return from read should be i.e 10 * * @return mraa result type */ mraa_result_t mraa_aio_set_bit(mraa_aio_context dev, int bits); /** * Gets the bit value mraa is shifting the analog read to. * @param dev the analog input context * * @return bit value mraa is set return from the read function */ int mraa_aio_get_bit(mraa_aio_context dev); #ifdef __cplusplus } #endif