MyHelperFunctions.h

/*
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2020 Sensnology AB
 * Full contributor list: https://github.com/mysensors/MySensors/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#ifndef MyHelperFunctions_h
#define MyHelperFunctions_h

/**
* Single character hex conversion
* @param c hex char
* @return byte representation of the paramter
*/
static uint8_t convertH2I(const char c) __attribute__((unused));

/**
* Lower nibble byte to hex conversion
* @param i byte
* @return hex char representation of the parameter
*/
static char convertI2H(const uint8_t i) __attribute__((unused));

/**
 * @brief Do a timing neutral memory comparison.
 *
 * The function behaves similar to memcmp with the difference that it will
 * always use the same number of instructions for a given number of bytes,
 * no matter how the two buffers differ and the response is either 0 or -1.
 *
 * @param a First buffer for comparison.
 * @param b Second buffer for comparison.
 * @param sz The number of bytes to compare.
 * @returns 0 if buffers match, -1 if they do not.
 */
static int timingneutralMemcmp(const void* a, const void* b, size_t sz) __attribute__((unused));

#endif