nfc.c
3.62 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <strings.h>
#include <inttypes.h>
#include "ui.h"
#include "nfc.h"
#include "printx.h"
#define DEVICE1 "/dev/ttyACM0"
#define SPEED B19200
#define NFC_POLLING_TIME 500000
#define WAIT_BEFORE_RETRY 50000
#define NFC_TAG_LENGTH 9
#define GET_DEVICE_MODEL 'A'
#define DEVICE_MODEL_NFC 'B'
#define GET_NFC_STATUS 'C'
#define NO_TAG_DETECTED 'D'
#define PROFESSOR_TAG 'E'
#define STUDENT_TAG 'F'
#define GET_TAG_DETAILS 'H'
// Globals
int serial_fd = -1;
bool stop = false;
struct termios saveterm;
bool init_serial(char* device, int speed)
{
struct termios new;
int fd=open(device,O_RDWR|O_NOCTTY|O_NONBLOCK);
if(fd<0)
return false;
tcgetattr(fd,&saveterm); // save current port settings
bzero(&new,sizeof(new));
new.c_cflag=CLOCAL|CREAD|speed|CS8;
new.c_iflag=0;
new.c_oflag=0;
new.c_lflag=0; // set input mode (non-canonical, no echo,...)
new.c_cc[VTIME]=0; // inter-character timer unused
new.c_cc[VMIN]=1; // blocking read until 1 char received
tcflush(fd, TCIFLUSH);
tcsetattr(fd,TCSANOW,&new);
serial_fd = fd;
sleep(2);
return true;
}
void close_serial()
{
tcsetattr(serial_fd,TCSANOW,&saveterm);
close(serial_fd);
}
unsigned char getData()
{
unsigned char buf;
while(read(serial_fd, &buf, 1) != 1)
usleep(WAIT_BEFORE_RETRY);
return buf;
}
void sendData(unsigned char data)
{
while(write(serial_fd, &data, 1) != 1)
usleep(WAIT_BEFORE_RETRY);
}
bool initNFC()
{
unsigned char data;
printx(DEBUG, NFC, "Connecting to interface 1\n");
if(init_serial(DEVICE1, SPEED))
{
printx(DEBUG, NFC, "Connected to an interface\n");
sendData(GET_DEVICE_MODEL);
printx(DEBUG, NFC, "Sended identification request %02x\n", GET_DEVICE_MODEL);
data = getData();
if(data == DEVICE_MODEL_NFC)
printx(INFO, NFC, "NFC Arduino connected\n");
else
printx(DEBUG, NFC, "NFC Arduino not found, response was %02x\n", data);
}
else
{
printx(WARNING, NFC, "Unable to connect to such interface\n");
return false;
}
return true;
}
bool isTagPresent(char* tag)
{
unsigned char data;
sendData(GET_NFC_STATUS);
data = getData();
if(data == PROFESSOR_TAG)
{
sendData(GET_TAG_DETAILS);
printx(INFO, NFC, "Professor Tag Detected %02x\n", data);
return (read(serial_fd, tag, 6) == 6);
}
else if(data == STUDENT_TAG)
{
sendData(GET_TAG_DETAILS);
printx(INFO, NFC, "Student Tag Detected\n");
tag[0] = getData();
printx(DEBUG, NFC, "Last read %02x\n", tag[0]);
tag[1] = getData();
printx(DEBUG, NFC, "Last read %02x\n", tag[1]);
tag[2] = getData();
printx(DEBUG, NFC, "Last read %02x\n", tag[2]);
tag[3] = getData();
printx(DEBUG, NFC, "Last read %02x\n", tag[3]);
tag[4] = getData();
printx(DEBUG, NFC, "Last read %02x\n", tag[4]);
tag[5] = getData();
printx(DEBUG, NFC, "Last read %02x\n", tag[5]);
tag[6] = getData();
printx(DEBUG, NFC, "Last read %02x\n", tag[6]);
tag[7] = getData();
printx(DEBUG, NFC, "Last read %02x\n", tag[7]);
return true;
}
else if(data == NO_TAG_DETECTED)
{
printx(DEBUG, NFC, "No Tag Detected\n");
return false;
}
else
{
printx(DEBUG, NFC, "Read data did not matched with expected data %02x\n", data);
return false;
}
return true;
}
void* processNFC(void* we)
{
char myTag[NFC_TAG_LENGTH];
char buffer[NFC_TAG_LENGTH];
while(!stop)
{
printx(DEBUG, NFC, "Scanning for tags\n");
if(isTagPresent(buffer))
{
sprintf(myTag, "%s", buffer);
printx(DEBUG, NFC, "Want to send %s as new tag\n", myTag);
setTagName(myTag);
}
usleep(NFC_POLLING_TIME);
}
return NULL;
}