Zoltan Hudak / ManchesterUART

Library for Manchester encoding using UART's hardware.

Dependents:   ManchesterUART_Transmitter ManchesterUART_Receiver

Manchester encoding using UART's hardware

This library implements Manchester code using UART. Each data byte is encoded into two bytes representing two nibbles of the original data. UART's hardware is then used to generate the Manchester encoded bit stream. Prior to decoding, the receiver converts the received bit stream to bytes using its UART. Start and stop patterns are sent to identify the boundaries (begin and end) of a data frame.

ACKNOWLEDGEMENT: The library is based on an article published by Adrian Mills.


Import programManchesterUART_Transmitter

Transmitter demo for the Manchester encoding library using UART's hardware.

Last commit 17 Oct 2018 by Zoltan Hudak


Import programManchesterUART_Receiver

Receiver demo for the Manchester encoding library using UART's hardware.

Last commit 17 Oct 2018 by Zoltan Hudak

NOTE: To perform a simple test (without radio link) connect the txPin on transmitter board to the rxPin on the receiver board and make sure that grounds are also connected one another.

ManchesterUART.h@1:b869674fe56e, 2018-07-30 (annotated)

Committer:
hudakz
Date:
Mon Jul 30 09:38:03 2018 +0000
Revision:
1:b869674fe56e
Parent:
0:e076052bcffd 
Preamble length can be modified.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hudakz 0:e076052bcffd 1 /*
hudakz 0:e076052bcffd 2 ******************************************************************************
hudakz 0:e076052bcffd 3 * @file ManchesterUART.h
hudakz 0:e076052bcffd 4 * @author Zoltan Hudak
hudakz 0:e076052bcffd 5 * @version
hudakz 0:e076052bcffd 6 * @date 2017-Nov-22
hudakz 0:e076052bcffd 7 * @brief Manchester code over UART for mbed
hudakz 0:e076052bcffd 8 ******************************************************************************
hudakz 0:e076052bcffd 9 * @attention
hudakz 0:e076052bcffd 10 *
hudakz 0:e076052bcffd 11 * <h2><center>&copy; COPYRIGHT(c) 2017 Zoltan Hudak <hudakz@outlook.com>
hudakz 0:e076052bcffd 12 *
hudakz 0:e076052bcffd 13 * All rights reserved.
hudakz 0:e076052bcffd 14
hudakz 0:e076052bcffd 15 This program is free software: you can redistribute it and/or modify
hudakz 0:e076052bcffd 16 it under the terms of the GNU General Public License as published by
hudakz 0:e076052bcffd 17 the Free Software Foundation, either version 3 of the License, or
hudakz 0:e076052bcffd 18 (at your option) any later version.
hudakz 0:e076052bcffd 19
hudakz 0:e076052bcffd 20 This program is distributed in the hope that it will be useful,
hudakz 0:e076052bcffd 21 but WITHOUT ANY WARRANTY; without even the implied warranty of
hudakz 0:e076052bcffd 22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
hudakz 0:e076052bcffd 23 GNU General Public License for more details.
hudakz 0:e076052bcffd 24
hudakz 0:e076052bcffd 25 You should have received a copy of the GNU General Public License
hudakz 0:e076052bcffd 26 along with this program. If not, see <http://www.gnu.org/licenses/>.
hudakz 0:e076052bcffd 27 */
hudakz 0:e076052bcffd 28 /*
hudakz 1:b869674fe56e 29 * This library implements Manchester code using UART serial connection. Each
hudakz 0:e076052bcffd 30 * data byte is encoded into two bytes representing two nibbles of the original
hudakz 1:b869674fe56e 31 * data byte. These two bytes are then sent over UART serial link connection.
hudakz 0:e076052bcffd 32 * The receiver reconstructs the original data byte from the two bytes received.
hudakz 0:e076052bcffd 33 * A start and stop pattern are sent to signify the begin and end of a message.
hudakz 1:b869674fe56e 34 *
hudakz 0:e076052bcffd 35 * The library is based on the article published by Adrian Mills:
hudakz 1:b869674fe56e 36 * http://www.quickbuilder.co.uk/qb/articles/Manchester_encoding_using_RS232.pdf
hudakz 0:e076052bcffd 37 */
hudakz 0:e076052bcffd 38 #ifndef MANCHESTERUART_H
hudakz 0:e076052bcffd 39 #define MANCHESTERUART_H
hudakz 0:e076052bcffd 40
hudakz 0:e076052bcffd 41 #include "mbed.h"
hudakz 0:e076052bcffd 42 #include "ManchesterMsg.h"
hudakz 0:e076052bcffd 43
hudakz 1:b869674fe56e 44 #define START 0xF0 // start pattern
hudakz 0:e076052bcffd 45
hudakz 1:b869674fe56e 46 #define STOP 0x0F // stop pattern
hudakz 0:e076052bcffd 47 class ManchesterUART
hudakz 0:e076052bcffd 48 {
hudakz 0:e076052bcffd 49 enum Error
hudakz 0:e076052bcffd 50 {
hudakz 0:e076052bcffd 51 NO_ERROR,
hudakz 0:e076052bcffd 52 ILLEGAL_CODE,
hudakz 0:e076052bcffd 53 RX_TIMEOUT,
hudakz 0:e076052bcffd 54 BUF_OVERRUN
hudakz 0:e076052bcffd 55 };
hudakz 0:e076052bcffd 56 public:
hudakz 0:e076052bcffd 57 /**
hudakz 0:e076052bcffd 58 * @brief Creates a ManchesterUART object
hudakz 0:e076052bcffd 59 * @note
hudakz 0:e076052bcffd 60 * @param txPin Pin name of transmitter line
hudakz 1:b869674fe56e 61 * @param rxPin Pin name of receiver line
hudakz 1:b869674fe56e 62 * @param preamble Number of start patterns at the begin of each transmission
hudakz 1:b869674fe56e 63 * @param baudrate Communication bit rate in bits per second. Defaults to 115200bps
hudakz 1:b869674fe56e 64 * @param timeout Receive timeout in seconds. Defaults to 5 seconds.
hudakz 0:e076052bcffd 65 * @retval
hudakz 0:e076052bcffd 66 */
hudakz 1:b869674fe56e 67 ManchesterUART
hudakz 1:b869674fe56e 68 (
hudakz 1:b869674fe56e 69 PinName txPin,
hudakz 1:b869674fe56e 70 PinName rxPin,
hudakz 1:b869674fe56e 71 int baudrate = 9600, /* bits/sec */
hudakz 1:b869674fe56e 72 uint8_t preamble = 8, /* number of start patterns */
hudakz 1:b869674fe56e 73 float rxTimeout = 5 /* seconds */
hudakz 1:b869674fe56e 74 ) :
hudakz 1:b869674fe56e 75 _serial(txPin, rxPin, baudrate),
hudakz 1:b869674fe56e 76 _rxTimeout(rxTimeout),
hudakz 1:b869674fe56e 77 _preamble(preamble),
hudakz 1:b869674fe56e 78 _error(NO_ERROR)
hudakz 1:b869674fe56e 79 { }
hudakz 0:e076052bcffd 80
hudakz 1:b869674fe56e 81 ~ ManchesterUART(void) { }
hudakz 0:e076052bcffd 82 void transmit(ManchesterMsg& msg);
hudakz 1:b869674fe56e 83 void attach(Callback<void ()> func, SerialBase::IrqType type = SerialBase::RxIrq) { _serial.attach(func, type); }
hudakz 0:e076052bcffd 84 bool receive(ManchesterMsg& msg);
hudakz 1:b869674fe56e 85 bool readable() { return _serial.readable(); }
hudakz 1:b869674fe56e 86 void baud(int baudrate) { _serial.baud(baudrate); }
hudakz 1:b869674fe56e 87 void setPreamble(uint8_t length) { _preamble = length; }
hudakz 1:b869674fe56e 88 void setRxTimeout(int seconds) { _rxTimeout = seconds; }
hudakz 1:b869674fe56e 89 Error lastError() { return _error; }
hudakz 0:e076052bcffd 90 private:
hudakz 0:e076052bcffd 91 Serial _serial;
hudakz 1:b869674fe56e 92 char* _data; // data array
hudakz 1:b869674fe56e 93 size_t _len; // data length in bytes
hudakz 1:b869674fe56e 94 size_t _maxLen; // data maximum length
hudakz 1:b869674fe56e 95 Timeout _timeout; // timeout
hudakz 1:b869674fe56e 96 float _rxTimeout; // timeout time in seconds
hudakz 1:b869674fe56e 97 uint8_t _preamble; // number of start patterns
hudakz 1:b869674fe56e 98 Error _error; // error flag
hudakz 0:e076052bcffd 99 void rxTimeout(void);
hudakz 0:e076052bcffd 100 void transmitByte(uint8_t data);
hudakz 0:e076052bcffd 101 uint8_t receiveByte(void);
hudakz 0:e076052bcffd 102 uint8_t getNibble(uint8_t nibble);
hudakz 0:e076052bcffd 103 };
hudakz 0:e076052bcffd 104 #endif // MANCHESTERUART_H