Jos van 't Hof / Mbed 2 deprecated Eavesdropper

Some code for a eavesdropper device.

Dependencies:   FastIO FastPWM mbed

main.cpp@0:050184ab5c0d, 2014-09-02 (annotated)

Committer:
Josvth
Date:
Tue Sep 02 08:20:13 2014 +0000
Revision:
0:050184ab5c0d
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Who changed what in which revision?

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Josvth 0:050184ab5c0d 1 #include "mbed.h"
Josvth 0:050184ab5c0d 2 #include "FastIO.h"
Josvth 0:050184ab5c0d 3 #include "FastPWM.h"
Josvth 0:050184ab5c0d 4
Josvth 0:050184ab5c0d 5 FastOut<LED1> led;
Josvth 0:050184ab5c0d 6
Josvth 0:050184ab5c0d 7 //Pin 29 and 30 are connected to pin 21
Josvth 0:050184ab5c0d 8 FastIn<p29> CAP_2_1_input;
Josvth 0:050184ab5c0d 9 FastIn<p30> CAP_2_0_input;
Josvth 0:050184ab5c0d 10 FastPWM pwm(p21);
Josvth 0:050184ab5c0d 11
Josvth 0:050184ab5c0d 12
Josvth 0:050184ab5c0d 13 Serial pc(USBTX, USBRX); // tx, rx
Josvth 0:050184ab5c0d 14
Josvth 0:050184ab5c0d 15 #define TIM2CR0 LPC_TIM2->CR0
Josvth 0:050184ab5c0d 16 #define TIM2CR1 LPC_TIM2->CR1
Josvth 0:050184ab5c0d 17
Josvth 0:050184ab5c0d 18 //void _cap_2_1_falling() {
Josvth 0:050184ab5c0d 19 // pc.printf("Interrupt: %X\n", LPC_TIM2->IR);
Josvth 0:050184ab5c0d 20 //led = 1;
Josvth 0:050184ab5c0d 21 //}
Josvth 0:050184ab5c0d 22
Josvth 0:050184ab5c0d 23 int main()
Josvth 0:050184ab5c0d 24 {
Josvth 0:050184ab5c0d 25
Josvth 0:050184ab5c0d 26 unsigned int ticks = 226;
Josvth 0:050184ab5c0d 27
Josvth 0:050184ab5c0d 28 // This signal should give a manchester encoded 101010101
Josvth 0:050184ab5c0d 29 pwm.period_ticks(ticks);
Josvth 0:050184ab5c0d 30 pwm.pulsewidth_ticks(ticks / 2);
Josvth 0:050184ab5c0d 31
Josvth 0:050184ab5c0d 32 // Setup TIM2
Josvth 0:050184ab5c0d 33
Josvth 0:050184ab5c0d 34 // SC
Josvth 0:050184ab5c0d 35 LPC_SC->PCONP |= (1<<22); // Power on the Timer2
Josvth 0:050184ab5c0d 36 LPC_SC->PCLKSEL1 &= ~(3<<12); // Select CCLK/4 for TIM2 (whipes previous clock setting)
Josvth 0:050184ab5c0d 37 LPC_SC->PCLKSEL1 |= (1<<12); // Select CCLK for TIM2
Josvth 0:050184ab5c0d 38
Josvth 0:050184ab5c0d 39 // CCR
Josvth 0:050184ab5c0d 40 LPC_TIM2->CCR |= (3 << 1); // Set CAP2.0 on falling edge with interrupt
Josvth 0:050184ab5c0d 41 LPC_TIM2->CCR |= (1 << 3); // Set CAP2.1 on rising edge
Josvth 0:050184ab5c0d 42
Josvth 0:050184ab5c0d 43 pc.printf("CCR: %X\n", LPC_TIM2->CCR);
Josvth 0:050184ab5c0d 44
Josvth 0:050184ab5c0d 45 // TCR
Josvth 0:050184ab5c0d 46 LPC_TIM2->TCR = 0x0002; // Reset TIM2
Josvth 0:050184ab5c0d 47 LPC_TIM2->TCR = 0x0001; // Enable TIM2
Josvth 0:050184ab5c0d 48
Josvth 0:050184ab5c0d 49 bool buffer [16];
Josvth 0:050184ab5c0d 50 int bits = 0;
Josvth 0:050184ab5c0d 51
Josvth 0:050184ab5c0d 52 //NVIC_DisableIRQ(TIMER2_IRQn);
Josvth 0:050184ab5c0d 53 //NVIC_SetVector(TIMER2_IRQn, (uint32_t)&_cap_2_1_falling);
Josvth 0:050184ab5c0d 54 //NVIC_EnableIRQ(TIMER2_IRQn);
Josvth 0:050184ab5c0d 55
Josvth 0:050184ab5c0d 56 while(1) {
Josvth 0:050184ab5c0d 57
Josvth 0:050184ab5c0d 58 //pc.printf("Interrupt: %X\n", LPC_TIM2->IR);
Josvth 0:050184ab5c0d 59
Josvth 0:050184ab5c0d 60 // Poll CRO (falling edge) intterupt
Josvth 0:050184ab5c0d 61 if (LPC_TIM2->IR & (1 << 4)) {
Josvth 0:050184ab5c0d 62
Josvth 0:050184ab5c0d 63 led = 1;
Josvth 0:050184ab5c0d 64
Josvth 0:050184ab5c0d 65 wait(100);
Josvth 0:050184ab5c0d 66
Josvth 0:050184ab5c0d 67 led = 0;
Josvth 0:050184ab5c0d 68
Josvth 0:050184ab5c0d 69 int diff = (TIM2CR0 - TIM2CR1) % 0xFFFFFFFF;
Josvth 0:050184ab5c0d 70
Josvth 0:050184ab5c0d 71 if (diff > 90 && diff < 136) { // Check if diff is equal to T=1/848kHz with 20% error
Josvth 0:050184ab5c0d 72 // bit transition
Josvth 0:050184ab5c0d 73
Josvth 0:050184ab5c0d 74 if (bits == 0) { // Start of sequence
Josvth 0:050184ab5c0d 75 buffer[0] = 1;
Josvth 0:050184ab5c0d 76 } else {
Josvth 0:050184ab5c0d 77 buffer[bits] = !buffer[bits-1];
Josvth 0:050184ab5c0d 78 }
Josvth 0:050184ab5c0d 79
Josvth 0:050184ab5c0d 80 pc.printf("Trasition: %u\n", diff);
Josvth 0:050184ab5c0d 81
Josvth 0:050184ab5c0d 82 } else if (diff > 45 && diff < 68) { // Check if diff is equal to T/2
Josvth 0:050184ab5c0d 83 // repeat last bit
Josvth 0:050184ab5c0d 84
Josvth 0:050184ab5c0d 85 if (bits == 0) { // Start of sequence
Josvth 0:050184ab5c0d 86 buffer[0] = 1;
Josvth 0:050184ab5c0d 87 } else {
Josvth 0:050184ab5c0d 88 buffer[bits] = buffer[bits-1];
Josvth 0:050184ab5c0d 89 }
Josvth 0:050184ab5c0d 90
Josvth 0:050184ab5c0d 91 pc.printf("Repeat: %u\n", diff);
Josvth 0:050184ab5c0d 92
Josvth 0:050184ab5c0d 93 } else {
Josvth 0:050184ab5c0d 94 // error, default to 1
Josvth 0:050184ab5c0d 95 pc.printf("Error: %u\n", diff);
Josvth 0:050184ab5c0d 96 }
Josvth 0:050184ab5c0d 97
Josvth 0:050184ab5c0d 98 bits = bits + 1 % 16;
Josvth 0:050184ab5c0d 99
Josvth 0:050184ab5c0d 100 LPC_TIM2->IR |= (1 << 4); // Clear IR by writing a one
Josvth 0:050184ab5c0d 101
Josvth 0:050184ab5c0d 102 }
Josvth 0:050184ab5c0d 103
Josvth 0:050184ab5c0d 104 // if (bits == 0) {
Josvth 0:050184ab5c0d 105 //
Josvth 0:050184ab5c0d 106 // for (int i = 0; i< 16; i++) {
Josvth 0:050184ab5c0d 107 // pc.printf("%u", (int) buffer[i]);
Josvth 0:050184ab5c0d 108 // }
Josvth 0:050184ab5c0d 109 //
Josvth 0:050184ab5c0d 110 // pc.printf("\n");
Josvth 0:050184ab5c0d 111 //
Josvth 0:050184ab5c0d 112 // }
Josvth 0:050184ab5c0d 113
Josvth 0:050184ab5c0d 114 // // Poll CRO (rising edge) intterupt
Josvth 0:050184ab5c0d 115 // if (LCP_TIM2-IR != (1 << 5)) {
Josvth 0:050184ab5c0d 116 //
Josvth 0:050184ab5c0d 117 // int diff = (TIM2CR1 - TIM2CR2) % 0xFFFFFFFF;
Josvth 0:050184ab5c0d 118 //
Josvth 0:050184ab5c0d 119 // // Do checks
Josvth 0:050184ab5c0d 120 //
Josvth 0:050184ab5c0d 121 // // End checks
Josvth 0:050184ab5c0d 122 //
Josvth 0:050184ab5c0d 123 //
Josvth 0:050184ab5c0d 124 // LCP_TIM2->IR &= ~(1 << 5);
Josvth 0:050184ab5c0d 125 // }
Josvth 0:050184ab5c0d 126
Josvth 0:050184ab5c0d 127
Josvth 0:050184ab5c0d 128
Josvth 0:050184ab5c0d 129 }
Josvth 0:050184ab5c0d 130
Josvth 0:050184ab5c0d 131 }