David Khosravi / Mbed 2 deprecated MTi-1_example_LPC1768

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Dependencies:   mbed-rtos mbed Xbus

Fork of MTi-1_example by Xsens

xbus/xbusparser.c@10:18a6661b7e59, 2015-05-13 (annotated)

Committer:
Alex Young
Date:
Wed May 13 17:42:38 2015 +0200
Revision:
10:18a6661b7e59
Parent:
9:e4dc986e59f6
Child:
14:155f9a55ec51
Add basic support for formatting xbus messages.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Alex Young 3:abc451d82b88 1 /*!
Alex Young 3:abc451d82b88 2 * \file
Alex Young 3:abc451d82b88 3 * \copyright
Alex Young 3:abc451d82b88 4 * Copyright (C) Xsens Technologies B.V., 2015. All rights reserved.
Alex Young 3:abc451d82b88 5 *
Alex Young 3:abc451d82b88 6 * This source code is intended for use only by Xsens Technologies BV and
Alex Young 3:abc451d82b88 7 * those that have explicit written permission to use it from
Alex Young 3:abc451d82b88 8 * Xsens Technologies BV.
Alex Young 3:abc451d82b88 9 *
Alex Young 3:abc451d82b88 10 * THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
Alex Young 3:abc451d82b88 11 * KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
Alex Young 3:abc451d82b88 12 * IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
Alex Young 3:abc451d82b88 13 * PARTICULAR PURPOSE.
Alex Young 3:abc451d82b88 14 */
Alex Young 3:abc451d82b88 15
Alex Young 3:abc451d82b88 16 #include "xbusparser.h"
Alex Young 10:18a6661b7e59 17 #include "xbusdef.h"
Alex Young 3:abc451d82b88 18 #include <stdlib.h>
Alex Young 3:abc451d82b88 19
Alex Young 3:abc451d82b88 20 enum XbusParserState
Alex Young 3:abc451d82b88 21 {
Alex Young 3:abc451d82b88 22 XBPS_Preamble, /*!< \brief Looking for preamble. */
Alex Young 3:abc451d82b88 23 XBPS_BusId, /*!< \brief Waiting for bus ID. */
Alex Young 3:abc451d82b88 24 XBPS_MessageId, /*!< \brief Waiting for message ID. */
Alex Young 3:abc451d82b88 25 XBPS_Length, /*!< \brief Waiting for length. */
Alex Young 3:abc451d82b88 26 XBPS_ExtendedLengthMsb, /*!< \brief Waiting for extended length MSB*/
Alex Young 3:abc451d82b88 27 XBPS_ExtendedLengthLsb, /*!< \brief Waiting for extended length LSB*/
Alex Young 3:abc451d82b88 28 XBPS_Payload, /*!< \brief Reading payload. */
Alex Young 3:abc451d82b88 29 XBPS_Checksum /*!< \brief Waiting for checksum. */
Alex Young 3:abc451d82b88 30 };
Alex Young 3:abc451d82b88 31
Alex Young 3:abc451d82b88 32 struct XbusParser
Alex Young 3:abc451d82b88 33 {
Alex Young 3:abc451d82b88 34 struct XbusParserCallback callbacks;
Alex Young 3:abc451d82b88 35 uint8_t* messageBuffer;
Alex Young 3:abc451d82b88 36 uint16_t currentMessageLength;
Alex Young 3:abc451d82b88 37 uint16_t payloadReceived;
Alex Young 3:abc451d82b88 38 uint8_t currentMessageId;
Alex Young 3:abc451d82b88 39 uint8_t checksum;
Alex Young 3:abc451d82b88 40 enum XbusParserState state;
Alex Young 3:abc451d82b88 41 };
Alex Young 3:abc451d82b88 42
Alex Young 3:abc451d82b88 43 size_t XbusParser_mem(void)
Alex Young 3:abc451d82b88 44 {
Alex Young 3:abc451d82b88 45 return sizeof(struct XbusParser);
Alex Young 3:abc451d82b88 46 }
Alex Young 3:abc451d82b88 47
Alex Young 3:abc451d82b88 48 struct XbusParser* XbusParser_create(struct XbusParserCallback const* callback)
Alex Young 3:abc451d82b88 49 {
Alex Young 3:abc451d82b88 50 void* mem = malloc(XbusParser_mem());
Alex Young 3:abc451d82b88 51 if (mem)
Alex Young 3:abc451d82b88 52 {
Alex Young 3:abc451d82b88 53 return XbusParser_init(mem, callback);
Alex Young 3:abc451d82b88 54 }
Alex Young 3:abc451d82b88 55 return NULL;
Alex Young 3:abc451d82b88 56 }
Alex Young 3:abc451d82b88 57
Alex Young 3:abc451d82b88 58 void XbusParser_destroy(struct XbusParser* parser)
Alex Young 3:abc451d82b88 59 {
Alex Young 3:abc451d82b88 60 free(parser);
Alex Young 3:abc451d82b88 61 }
Alex Young 3:abc451d82b88 62
Alex Young 3:abc451d82b88 63 struct XbusParser* XbusParser_init(void* parserMem, struct XbusParserCallback const* callback)
Alex Young 3:abc451d82b88 64 {
Alex Young 3:abc451d82b88 65 struct XbusParser* parser = (struct XbusParser*)parserMem;
Alex Young 3:abc451d82b88 66 parser->state = XBPS_Preamble;
Alex Young 3:abc451d82b88 67 parser->callbacks.allocateBuffer = callback->allocateBuffer;
Alex Young 3:abc451d82b88 68 parser->callbacks.handleMessage = callback->handleMessage;
Alex Young 3:abc451d82b88 69 return parser;
Alex Young 3:abc451d82b88 70 }
Alex Young 3:abc451d82b88 71
Alex Young 3:abc451d82b88 72 static void prepareForPayload(struct XbusParser* parser)
Alex Young 3:abc451d82b88 73 {
Alex Young 3:abc451d82b88 74 parser->messageBuffer = parser->callbacks.allocateBuffer(parser->currentMessageLength);
Alex Young 3:abc451d82b88 75 parser->payloadReceived = 0;
Alex Young 3:abc451d82b88 76 }
Alex Young 3:abc451d82b88 77
Alex Young 3:abc451d82b88 78 void XbusParser_parseByte(struct XbusParser* parser, const uint8_t byte)
Alex Young 3:abc451d82b88 79 {
Alex Young 3:abc451d82b88 80 switch (parser->state)
Alex Young 3:abc451d82b88 81 {
Alex Young 3:abc451d82b88 82 case XBPS_Preamble:
Alex Young 3:abc451d82b88 83 if (byte == XBUS_PREAMBLE)
Alex Young 3:abc451d82b88 84 {
Alex Young 3:abc451d82b88 85 parser->checksum = 0;
Alex Young 3:abc451d82b88 86 parser->state = XBPS_BusId;
Alex Young 3:abc451d82b88 87 }
Alex Young 3:abc451d82b88 88 break;
Alex Young 3:abc451d82b88 89
Alex Young 3:abc451d82b88 90 case XBPS_BusId:
Alex Young 3:abc451d82b88 91 parser->checksum += byte;
Alex Young 3:abc451d82b88 92 parser->state = XBPS_MessageId;
Alex Young 3:abc451d82b88 93 break;
Alex Young 3:abc451d82b88 94
Alex Young 3:abc451d82b88 95 case XBPS_MessageId:
Alex Young 3:abc451d82b88 96 parser->checksum += byte;
Alex Young 3:abc451d82b88 97 parser->currentMessageId = byte;
Alex Young 3:abc451d82b88 98 parser->state = XBPS_Length;
Alex Young 3:abc451d82b88 99 break;
Alex Young 3:abc451d82b88 100
Alex Young 3:abc451d82b88 101 case XBPS_Length:
Alex Young 3:abc451d82b88 102 parser->checksum += byte;
Alex Young 3:abc451d82b88 103 if (byte == XBUS_NO_PAYLOAD)
Alex Young 3:abc451d82b88 104 {
Alex Young 9:e4dc986e59f6 105 parser->currentMessageLength = byte;
Alex Young 3:abc451d82b88 106 parser->state = XBPS_Checksum;
Alex Young 3:abc451d82b88 107 }
Alex Young 3:abc451d82b88 108 else if (byte < XBUS_EXTENDED_LENGTH)
Alex Young 3:abc451d82b88 109 {
Alex Young 3:abc451d82b88 110 parser->currentMessageLength = byte;
Alex Young 3:abc451d82b88 111 prepareForPayload(parser);
Alex Young 3:abc451d82b88 112 parser->state = XBPS_Payload;
Alex Young 3:abc451d82b88 113 }
Alex Young 3:abc451d82b88 114 else
Alex Young 3:abc451d82b88 115 {
Alex Young 3:abc451d82b88 116 parser->state = XBPS_ExtendedLengthMsb;
Alex Young 3:abc451d82b88 117 }
Alex Young 3:abc451d82b88 118 break;
Alex Young 3:abc451d82b88 119
Alex Young 3:abc451d82b88 120 case XBPS_ExtendedLengthMsb:
Alex Young 3:abc451d82b88 121 parser->checksum += byte;
Alex Young 3:abc451d82b88 122 parser->currentMessageLength = ((uint16_t)byte) << 8;
Alex Young 3:abc451d82b88 123 parser->state = XBPS_ExtendedLengthLsb;
Alex Young 3:abc451d82b88 124 break;
Alex Young 3:abc451d82b88 125
Alex Young 3:abc451d82b88 126 case XBPS_ExtendedLengthLsb:
Alex Young 3:abc451d82b88 127 parser->checksum += byte;
Alex Young 3:abc451d82b88 128 parser->currentMessageLength |= byte;
Alex Young 3:abc451d82b88 129 prepareForPayload(parser);
Alex Young 3:abc451d82b88 130 parser->state = XBPS_Payload;
Alex Young 3:abc451d82b88 131 break;
Alex Young 3:abc451d82b88 132
Alex Young 3:abc451d82b88 133 case XBPS_Payload:
Alex Young 3:abc451d82b88 134 parser->checksum += byte;
Alex Young 3:abc451d82b88 135 if (parser->messageBuffer)
Alex Young 3:abc451d82b88 136 {
Alex Young 3:abc451d82b88 137 parser->messageBuffer[parser->payloadReceived] = byte;
Alex Young 3:abc451d82b88 138 }
Alex Young 3:abc451d82b88 139 if (++parser->payloadReceived == parser->currentMessageLength)
Alex Young 3:abc451d82b88 140 {
Alex Young 3:abc451d82b88 141 parser->state = XBPS_Checksum;
Alex Young 3:abc451d82b88 142 }
Alex Young 3:abc451d82b88 143 break;
Alex Young 3:abc451d82b88 144
Alex Young 3:abc451d82b88 145 case XBPS_Checksum:
Alex Young 3:abc451d82b88 146 parser->checksum += byte;
Alex Young 3:abc451d82b88 147 if ((parser->checksum == 0) && parser->messageBuffer)
Alex Young 3:abc451d82b88 148 {
Alex Young 3:abc451d82b88 149 parser->callbacks.handleMessage(parser->currentMessageId,
Alex Young 3:abc451d82b88 150 parser->currentMessageLength,
Alex Young 3:abc451d82b88 151 parser->messageBuffer);
Alex Young 3:abc451d82b88 152 }
Alex Young 3:abc451d82b88 153 parser->state = XBPS_Preamble;
Alex Young 3:abc451d82b88 154 break;
Alex Young 3:abc451d82b88 155 }
Alex Young 3:abc451d82b88 156 }
Alex Young 3:abc451d82b88 157
Alex Young 3:abc451d82b88 158 void XbusParser_parseBuffer(struct XbusParser* parser, uint8_t const* buf, size_t bufSize)
Alex Young 3:abc451d82b88 159 {
Alex Young 3:abc451d82b88 160 for (size_t i = 0; i < bufSize; ++i)
Alex Young 3:abc451d82b88 161 {
Alex Young 3:abc451d82b88 162 XbusParser_parseByte(parser, buf[i]);
Alex Young 3:abc451d82b88 163 }
Alex Young 3:abc451d82b88 164 }
Alex Young 3:abc451d82b88 165