root / toolbox / rfid.c @ master
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| 1 | 12ea39cc | Tom Mullins | #include <string.h> |
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| 2 | 6ca98a3f | Tom Mullins | #include <stdint.h> |
| 3 | 9b2b6d91 | Tom Mullins | #include <util/delay.h> |
| 4 | #include "rfid.h" |
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| 5 | #include "serial.h" |
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| 6 | |||
| 7 | 2f795968 | Tom Mullins | #define MF_SELECT_CMD 0x83 |
| 8 | |||
| 9 | static uint8_t select_cmd[] = {0xFF, 0, 1, MF_SELECT_CMD, MF_SELECT_CMD + 1}; |
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| 10 | 6fbe093f | Tom Mullins | |
| 11 | #define FRAME_SIZE(data_size) ((data_size)+4) |
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| 12 | 2f795968 | Tom Mullins | #define RFID_DATA_SIZE (RFID_SERNO_SIZE+2) |
| 13 | #define MAX_FRAME_SIZE FRAME_SIZE(RFID_DATA_SIZE)
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| 14 | 6fbe093f | Tom Mullins | |
| 15 | #define RESP_START 0 |
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| 16 | #define RESP_RESERVED 1 |
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| 17 | #define RESP_LENGTH 2 |
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| 18 | #define RESP_CMD 3 |
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| 19 | #define RESP_DATA 4 |
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| 20 | static uint8_t response[MAX_FRAME_SIZE];
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| 21 | static uint8_t resp_idx;
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| 22 | 9b2b6d91 | Tom Mullins | |
| 23 | 6ca98a3f | Tom Mullins | static uint8_t serno[RFID_SERNO_SIZE];
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| 24 | 9b2b6d91 | Tom Mullins | |
| 25 | static void zero_serno() { |
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| 26 | int i;
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| 27 | for (i = 0; i < RFID_SERNO_SIZE; i++) { |
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| 28 | serno[i] = 0;
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| 29 | } |
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| 30 | } |
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| 31 | |||
| 32 | void rfid_init() {
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| 33 | serial_init(); |
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| 34 | } |
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| 35 | |||
| 36 | bbf2f5ad | Tom Mullins | void rfid_start_read() {
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| 37 | 6fbe093f | Tom Mullins | resp_idx = 0;
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| 38 | bbf2f5ad | Tom Mullins | serial_flush(); |
| 39 | 2f795968 | Tom Mullins | serial_write(select_cmd, sizeof(select_cmd));
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| 40 | 6fbe093f | Tom Mullins | } |
| 41 | |||
| 42 | char parse_response() {
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| 43 | uint8_t sum; |
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| 44 | int resp_csum, i;
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| 45 | |||
| 46 | 2f795968 | Tom Mullins | if (response[RESP_CMD] != MF_SELECT_CMD) {
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| 47 | // invalid response, ignore
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| 48 | 6fbe093f | Tom Mullins | zero_serno(); |
| 49 | return 0; |
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| 50 | } |
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| 51 | |||
| 52 | 2f795968 | Tom Mullins | if (response[RESP_LENGTH] != RFID_DATA_SIZE) {
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| 53 | // wrong response length, assume there's no card
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| 54 | zero_serno(); |
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| 55 | return 1; |
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| 56 | } |
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| 57 | |||
| 58 | 6fbe093f | Tom Mullins | resp_csum = response[RESP_LENGTH] + RESP_CMD; |
| 59 | sum = 0;
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| 60 | for (i = RESP_LENGTH; i < resp_csum; i++) {
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| 61 | sum += response[i]; |
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| 62 | } |
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| 63 | if (response[resp_csum] != sum) {
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| 64 | 2f795968 | Tom Mullins | zero_serno(); |
| 65 | return 0; |
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| 66 | 6fbe093f | Tom Mullins | } |
| 67 | |||
| 68 | memcpy(serno, &response[RESP_DATA+1], RFID_SERNO_SIZE);
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| 69 | return 1; |
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| 70 | 532ba0bd | Tom Mullins | } |
| 71 | |||
| 72 | char rfid_poll() {
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| 73 | int c;
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| 74 | |||
| 75 | 6ca98a3f | Tom Mullins | while ((c = serial_read()) >= 0) { |
| 76 | 532ba0bd | Tom Mullins | |
| 77 | 6fbe093f | Tom Mullins | if (resp_idx < sizeof(response)) { |
| 78 | response[resp_idx] = c; |
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| 79 | 532ba0bd | Tom Mullins | } |
| 80 | 6fbe093f | Tom Mullins | resp_idx++; |
| 81 | 532ba0bd | Tom Mullins | |
| 82 | 6fbe093f | Tom Mullins | if (resp_idx == 1) { |
| 83 | |||
| 84 | // restart if the frame start is invalid
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| 85 | if (response[RESP_START] != 0xFF) { |
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| 86 | resp_idx = 0;
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| 87 | } |
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| 88 | 532ba0bd | Tom Mullins | |
| 89 | 6fbe093f | Tom Mullins | } else if (resp_idx > RESP_LENGTH) { |
| 90 | |||
| 91 | // check if we're done with current packet
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| 92 | if (resp_idx >= FRAME_SIZE(response[RESP_LENGTH])) {
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| 93 | 2f795968 | Tom Mullins | rfid_start_read(); |
| 94 | 6fbe093f | Tom Mullins | if (parse_response()) {
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| 95 | return 1; |
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| 96 | } |
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| 97 | } |
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| 98 | |||
| 99 | } |
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| 100 | 9b2b6d91 | Tom Mullins | } |
| 101 | 532ba0bd | Tom Mullins | |
| 102 | return 0; |
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| 103 | 9b2b6d91 | Tom Mullins | } |
| 104 | |||
| 105 | 6ca98a3f | Tom Mullins | void rfid_get_serno(uint8_t *buf) {
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| 106 | 12ea39cc | Tom Mullins | memcpy(buf, serno, sizeof(serno));
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| 107 | } |