1 | /************************************************************************
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2 | * *
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3 | * Filename: Main.c *
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4 | * Created on 28. Dezember 2017, 17:31 *
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5 | * File Version: 1.0 *
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6 | * *
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7 | * Author: Max *
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8 | * *
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9 | *************************************************************************
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10 | * *
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11 | * Architecture: Mid-range PIC *
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12 | * Processor: 16LF1509 *
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13 | * Compiler: MPLAB XC8 v1.44 (Free mode) *
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14 | * *
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15 | *************************************************************************/
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16 |
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17 | #include "Init.h"
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18 |
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19 | //Functions---------------------------------------------------------------------
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20 | // Initialisation
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21 | void init(void) {
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22 |
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23 | // default value's
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24 | ManDecode.midbit_low = 13;
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25 | ManDecode.midbit_high = 37;
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26 | ManDecode.period_high = 38;
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27 | ManDecode.period_high = 62;
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28 |
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29 | TRISA = 0b111101; // configure RA1 (only) as an output (0 -> output, 1 -> input)
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30 | LATA = 0; // set RA1 low
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31 | ANSELA = 0; // disable analog input mode for all pins
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32 | // --> RA2 is a digital input
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33 | // configure oscillator
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34 | OSCCONbits.SCS1 = 1; // select internal clock -- OSCCON oscillator control register
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35 | OSCCONbits.IRCF = 0b1100; // internal oscillator = 2 MHz
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36 | // configure Timer0
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37 | OPTION_REGbits.TMR0CS = 0; // select timer mode
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38 | OPTION_REGbits.PSA = 1; // if '0' assign's prescaler to Timer0
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39 | // OPTION_REGbits.PS = 0b111; // prescale 1:128
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40 | // -> increment TMR0 every 4 us
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41 | // configure Interrupt on changing edge
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42 | OPTION_REGbits.INTEDG = 1; // interrupt on rising edge
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43 |
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44 | // enable interrupts
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45 | INTCONbits.INTF = 0; // clearing external interrupt flags
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46 | INTCONbits.TMR0IF = 0; // clearing Timer0 flag
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47 | INTCONbits.INTE = 1; // enable external interrupt
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48 | INTCONbits.TMR0IE = 1; // enable Timer0 interrupt
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49 | ei(); // enable global interrupts
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50 |
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51 |
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52 | }
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53 | /***** INTERRUPT SERVICE ROUTINE *****/
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54 | void interrupt isr(void)
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55 | {
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56 | static uint time;
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57 | //*** Service external interrupt
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58 | //
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59 | // Triggered on changing edge on INT pin
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60 | //
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61 | //
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62 |
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63 | if(INTCONbits.INTF && !INTCONbits.TMR0IF) {
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64 | time=TMR0;
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65 | M_Time = time;
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66 | TMR0=0; // start counting
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67 | if (M_Time >= ManDecode.midbit_low) {
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68 | if (M_Time <= ManDecode.midbit_high) {
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69 | // Count Bit in Preamble Buffer
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70 | if(!PreDetect) {
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71 | SetPreCounter();
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72 | }
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73 | else if(PreDetect) {
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74 | // Read Start-/Stopbit and Payload
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75 | GetPayload();
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76 |
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77 | }
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78 | }
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79 | }
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80 | else { // reset Preamble and Payload Buffer
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81 | Preamble = 0b00000000;
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82 | Payload = 0b0000000000000000;
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83 | }
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84 | IntTrigger = ~IntTrigger; // change interrupt to falling/rising edge
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85 | }
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86 | else if (INTCONbits.TMR0IF) { // if Timer overflows -> reset
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87 | INTCONbits.TMR0IF = 0;
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88 | IntTrigger = 1; // change interrupt to rising edge
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89 | Preamble = 0b00000000;
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90 | Payload = 0b0000000000000000;
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91 | }
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92 | INTCONbits.INTF = 0; // clear interrupt flag
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93 |
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94 | }
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95 | void GetPayload(void) {
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96 | Payload <<= 1;
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97 | if(IntTrigger && (Pcounter != 16)) {
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98 | Payload |= 1;
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99 | Pcounter++;
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100 | }
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101 | // Test if Payload is True
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102 | if(Pcounter == 16) {
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103 | // Test if Startbit and Stopbit are sent
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104 | uint check = 0b10000000000000001;
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105 | uint data_complete = 0b10000000000000000;
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106 | if((Payload&check)== data_complete) {
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107 | // wait for guardtime and decode
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108 | data_send = 1;
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109 | // Man_Decode(); /// Not yet implemented
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110 | }
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111 | }
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112 | }
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113 | void SetPreCounter(void) {
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114 | Preamble <<= 1;
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115 | if(IntTrigger) {
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116 | Preamble |= 1;
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117 | if(Preamble == 170) {
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118 | PreDetect = 1;
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119 | }
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120 | }
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121 | }
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122 |
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123 | void main(){
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124 | init();
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125 | if(data_send) {
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126 | // Man_Encode(); Not yet implemented -- decodes received Data
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127 | }
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128 | }
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