pjon.h

00001 
00002  /*-O//\         __     __
00003    |-gfo\       |__| | |  | |\ |
00004    |!y°o:\      |  __| |__| | \| v1.0
00005    |y"s§+`\     Giovanni Blu Mitolo 2012 - 2015
00006   /so+:-..`\    gioscarab@gmail.com
00007   |+/:ngr-*.`\
00008   |5/:%&-a3f.:;\     PJON is a device communications bus system that connects up to 255
00009   \+//u/+g%{osv,,\    arduino boards over one wire up to 5.29kB/s data communication speed.
00010     \=+&/osw+olds.\\   Contains acknowledge, collision detection, CRC and encpryption all done
00011        \:/+-.-°-:+oss\  with micros() and delayMicroseconds(), with no use of interrupts or timers.
00012         | |       \oy\\  Pull down resistor on the bus is generally used to reduce interference.
00013         > <
00014   _____-| |-________________________________________________________________________
00015  | BIT_WIDTH 20 | BIT_SPACER 56 | ACCEPTANCE  20 | READ_DELAY 8                     |
00016  |----------------------------------------------------------------------------------|
00017  |Transfer speed: 5.29kB/s     | Absolute bandwidth:  3.23 kB/s                     |
00018  |Baud rate:      42372 baud   | Data throughput:     2.68 kB/s                     |
00019  |__________________________________________________________________________________|
00020 
00021 Copyright (c) 2012-2015, Giovanni Blu Mitolo All rights reserved.
00022 
00023 Redistribution and use in source and binary forms, with or without
00024 modification, are permitted provided that the following conditions are met:
00025 - Redistributions of source code must retain the above copyright
00026    notice, this list of conditions and the following disclaimer.
00027 
00028 -  Redistributions in binary form must reproduce the above copyright
00029    notice, this list of conditions and the following disclaimer in the
00030    documentation and/or other materials provided with the distribution.
00031 
00032 -  All advertising materials mentioning features or use of this software
00033    must display the following acknowledgement:
00034    This product includes PJON software developed by Giovanni Blu Mitolo.
00035 
00036 -  Neither the name of PJON, PJON_ASK nor the
00037    names of its contributors may be used to endorse or promote products
00038    derived from this software without specific prior written permission.
00039 
00040 This software is provided by the copyright holders and contributors"as is"
00041 and any express or implied warranties, including, but not limited to, the
00042 implied warranties of merchantability and fitness for a particular purpose
00043 are disclaimed. In no event shall the copyright holder or contributors be
00044 liable for any direct, indirect, incidental, special, exemplary, or consequential
00045 damages (including, but not limited to, procurement of substitute goods or services;
00046 loss of use, data, or profits; or business interruption) however caused and on any
00047 theory of liability, whether in contract, strict liability, or tort (including
00048 negligence or otherwise) arising in any way out of the use of this software, even if
00049 advised of the possibility of such damage. */
00050 
00051 #ifndef PJON_h
00052   #define PJON_h
00053 
00054   #include "mbed.h"
00055 
00056   /* COMPATIBILITY_MODE set to true:
00057   Run the network with a cautious speed to support all architectures.
00058   8Mhz devices will be able to communicate with 16 or more Mhz devices.
00059      COMPATIBILITY_MODE set to false:
00060   Run the network at full speed with the best performances, but is
00061   indicated only for networks made by a group of devices with the
00062   same architecture / processor (for example 10 Arduino Uno) */
00063 
00064   #define  COMPATIBILITY_MODE true
00065 
00066 //mbed (needs tweaking)
00067 /*
00068       #define BIT_WIDTH 52
00069       #define BIT_SPACER 121
00070       #define ACCEPTANCE 51
00071       #define READ_DELAY 29
00072   */
00073        #define BIT_WIDTH 45
00074       #define BIT_SPACER 113
00075       #define ACCEPTANCE 45
00076       #define READ_DELAY 23    
00077   /* The following constants setup are quite conservative and determined only
00078      with a huge amount of time and blind testing (without oscilloscope)
00079      tweaking values and analysing results. Theese can be changed to obtain
00080      faster speed. Probably you need experience, time and an oscilloscope. */
00081 
00082   #if defined(__AVR_ATmega88__) || defined(__AVR_ATmega168__) || defined(__AVR_ATmega328__) || defined(__AVR_ATmega328P__)
00083     #if (F_CPU == 16000000 && !COMPATIBILITY_MODE)
00084       #define BIT_WIDTH 20
00085       #define BIT_SPACER 56
00086       #define ACCEPTANCE 20
00087       #define READ_DELAY 8
00088     #endif
00089     #if (F_CPU == 8000000 || COMPATIBILITY_MODE)
00090       #define BIT_WIDTH 40
00091       #define BIT_SPACER 112
00092       #define ACCEPTANCE 40
00093       #define READ_DELAY 16
00094     #endif
00095   #endif
00096 
00097   #if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
00098     #if (F_CPU == 16000000 && !COMPATIBILITY_MODE)
00099       /* Mega has shorter values than Duemianove / Uno because
00100       micros() produces longer delays on ATmega1280/2560 */
00101       #define BIT_WIDTH 18
00102       #define BIT_SPACER 54
00103       #define ACCEPTANCE 18
00104       #define READ_DELAY 8
00105     #endif
00106     #if (F_CPU == 8000000 || COMPATIBILITY_MODE)
00107       /* Mega has shorter values than Duemianove / Uno because
00108       micros() produces longer delays on ATmega1280/2560 */
00109       #define BIT_WIDTH 38
00110       #define BIT_SPACER 110
00111       #define ACCEPTANCE 38
00112       #define READ_DELAY 16
00113     #endif
00114   #endif
00115 
00116   #if defined(__AVR_ATtiny45__) || defined(__AVR_ATtiny85__)
00117     #if (F_CPU == 8000000 || COMPATIBILITY_MODE) // Internal clock
00118       /* ATtiny has shorter values than Duemianove / Uno because
00119       micros() produces longer delays on ATtiny45/85 */
00120       #define BIT_WIDTH 35
00121       #define BIT_SPACER 108
00122       #define ACCEPTANCE 35
00123       #define READ_DELAY 16
00124     #endif
00125   #endif
00126 
00127 #endif
00128 
00129 // Protocol symbols
00130 #define ACK        6
00131 #define NAK        21
00132 #define FAIL       0x100
00133 #define BUSY       666
00134 #define BROADCAST  124
00135 #define TO_BE_SENT 74
00136 
00137 // Errors
00138 #define CONNECTION_LOST 101
00139 #define PACKETS_BUFFER_FULL 102
00140 #define MEMORY_FULL 103
00141 
00142 // Maximum sending attempts before throwing CONNECTON_LOST error
00143 #define MAX_ATTEMPTS 250
00144 
00145 // Packets buffer length, if full PACKET_BUFFER_FULL error is thrown
00146 #define MAX_PACKETS 10
00147 
00148 // Max packet length, higher if necessary (affects memory)
00149 #define PACKET_MAX_LENGTH 50
00150 
00151 struct packet {
00152   uint8_t attempts;
00153   uint8_t device_id;
00154   char *content;
00155   uint8_t length;
00156   uint32_t registration;
00157   int state;
00158   uint32_t timing;
00159 };
00160 
00161 typedef void (* receiver)(uint8_t length, uint8_t *payload);
00162 typedef void (* pjon_error)(uint8_t code, uint8_t data);
00163 
00164 static void dummy_error_handler(uint8_t code, uint8_t data) {
00165     DigitalOut myled(LED1);
00166     myled = 1;
00167     };
00168 
00169 class PJON {
00170 
00171   public:
00172     PJON(PinName input_pin);
00173     PJON(PinName input_pin, uint8_t id);
00174 
00175     void initialize();
00176 
00177     void set_id(uint8_t id);
00178     void set_receiver(receiver r);
00179     void set_error(pjon_error e);
00180 
00181     int receive_byte();
00182     int receive();
00183     int receive(unsigned long duration);
00184 
00185     void send_bit(uint8_t VALUE, int duration);
00186     void send_byte(uint8_t b);
00187     int  send_string(uint8_t id, char *string, uint8_t length);
00188     int  send(uint8_t id, char *packet, uint8_t length, unsigned long timing = 0);
00189 
00190     void update();
00191     void remove(int id);
00192 
00193     uint8_t read_byte();
00194     bool can_start();
00195 
00196     uint8_t syncronization_bit();
00197 
00198     uint8_t data[PACKET_MAX_LENGTH];
00199     packet  packets[MAX_PACKETS];
00200 
00201   private:
00202     DigitalInOut _input_pin;
00203     uint8_t   _device_id;
00204     //int       _input_pin;
00205     receiver  _receiver;
00206     pjon_error     _error;
00207     Timer _reg_timer;
00208 };