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1 | 6 | kaklik | /*! \file edpdefs.h \brief Emerald Data Protocol Defines and Constants. */ |
2 | //***************************************************************************** |
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3 | // |
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4 | // File Name : 'edpdefs.h' |
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5 | // Title : Emerald Data Protocol Defines and Constants |
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6 | // Author : Pascal Stang - Copyright (C) 2003 |
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7 | // Created : 09/08/2003 |
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8 | // Revised : 09/08/2003 |
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9 | // Version : 0.1 |
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10 | // Target MCU : Atmel AVR Series |
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11 | // Editor Tabs : 4 |
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12 | // |
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13 | // This code is distributed under the GNU Public License |
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14 | // which can be found at http://www.gnu.org/licenses/gpl.txt |
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15 | // |
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16 | //***************************************************************************** |
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17 | |||
18 | #ifndef EDPDEFS_H |
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19 | #define EDPDEFS_H |
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20 | |||
21 | // **** Constant Definitions ***** |
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22 | // ---- Message Size, etc ---- |
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23 | // Standard defines for various message format parameters |
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24 | #define I2C_MAX_COMMAND_LENGTH 127 // [param1]...[param127] (does not include Command, From |
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25 | // or Chk) Note that this an absolute maximum, |
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26 | // subsystems/nodes are free to set lower maximum lengths |
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27 | // For versions pre rev5, this was fixed at 5. |
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28 | #define I2C_MAX_DATA_PACKET_LENGTH 127 // Raw Data: [data1]...[data126][Chk] (includes Chk for |
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29 | |||
30 | |||
31 | // ---- Communication OK (value all uppercase ('A'-'Z') |
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32 | #define EDP_RESP_ACK 'A' // indicates the command (to_send) was sent but has no return value. |
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33 | #define EDP_RESP_DATA_REPLY 'R' // command valid and has return, examine reply and length for details |
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34 | |||
35 | // ---- Communication Error (values all lowercase ('a'-'z')) |
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36 | #define EDP_RESP_UNKWN_CMD 'u' // given command is unrecognized by the subsystem at that address |
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37 | #define EDP_RESP_CMD_CHK_ERROR 'c' // checksum error sending command |
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38 | #define EDP_RESP_DATA_CHK_ERROR 'd' // checksum error receiving data |
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39 | #define EDP_RESP_SEQUENCE_ERROR 's' // read/write out of order |
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40 | #define EDP_RESP_READ_BEFORE_WRITE 'b' // requested read before writting associated Command |
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41 | #define EDP_RESP_TOO_LONG 'l' // The command sent exceeds the maximum command length for node |
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42 | #define EDP_RESP_TOO_FEW_PARAMS 'p' // The command sent has too few parameters |
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43 | #define EDP_RESP_INCORRECT_PARAM 'i' // Parameters are incorrect (but there are the right number) |
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44 | #define EDP_RESP_BUSY 'b' // The subsystem is still alive, but too busy to reply (AVOID USING) |
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45 | #define EDP_RESP_NOT_ALLOWED 'n' // The command is recognized, but not allowed in the current |
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46 | // operating mode. Try another command, or try again later |
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47 | #define EDP_RESP_OTHER_ERROR 'e' // unspecified EDP/I2C error |
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48 | |||
49 | // ---- Check Sum ---- |
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50 | /* The Checksum that is used is a rolling 8-bit sum from the [From] to the last parameter byte of a command |
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51 | packet and from the [Length] to the last data byte of a Data packet. This sum is then 1-complemented |
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52 | (~, not) and passed as [Chk]. This prevents a series of 0x00 replys from passing the correct check sum. |
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53 | Because of the inversion, a packet with all zeros should have a checksum of 0xFF. |
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54 | |||
55 | The other nice feature of this checksum, is that no matter what the data is, if you add the checksum |
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56 | ([Chk]) to the final sum, you should get 0xFF. |
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57 | |||
58 | To make it even cleaner, you can start the rolling checksum at 0x01 such that when you add in all of the |
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59 | data bytes and the [Chk] byte, you get 0x00. This effectively makes the whole operation a twos complement |
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60 | */ |
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61 | #define EDP_CHECKSUM_INIT 0x01 |
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62 | |||
63 | // -------- Reserved I2C commands --------- |
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64 | // Define a short list of reserved commands. Subsystems can choose whether or |
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65 | // not to implement these commands, but if they are implemented, they must |
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66 | // function as described below. |
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67 | |||
68 | //Reserved Commands |
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69 | #define EDP_CMD_SET_TIME ':' //0x3A Set the subsystem time, realtime.h format |
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70 | #define EDP_CMD_RESERVED_1 ';' //0x3B Reserved for future command |
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71 | #define EDP_CMD_ROM_WRITE '<' //0x3C Write to program ROM (uploadable code) |
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72 | #define EDP_CMD_RESERVED_2 '=' //0x3D Reserved for future command |
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73 | #define EDP_CMD_MEM_READ '>' //0x3E Read from program ROM (check program) |
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74 | #define EDP_CMD_HELP '?' //0x3F Return human readable help string(s) |
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75 | #define EDP_CMD_STATUS '@' //0x40 Get subsystem status |
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76 | |||
77 | |||
78 | #define I2C_DATA_CONTINUE_MASK 0x80 // If MSB of length is set, then the data continues beyond |
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79 | // this data packet |
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80 | |||
81 | |||
82 | #endif |
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