Revision 336
Updated wireless to use a circular buffer instead of a queue using malloc. Tested on both the computer and robots with a token ring, and was successful.
| xbee.c | ||
|---|---|---|
| 54 | 54 |
#include <stdlib.h> |
| 55 | 55 |
#include <string.h> |
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|
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#include <queue.h> |
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|
|
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#define XBEE_FRAME_START 0x7E |
| 60 | 58 |
|
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/*Frame Types*/ |
| ... | ... | |
| 108 | 106 |
pthread_t* xbee_listen_thread; |
| 109 | 107 |
#endif |
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|
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Queue* xbee_queue; |
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// TODO: is this a good size? |
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#define XBEE_BUFFER_SIZE 256 |
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// a buffer for data received from the XBee |
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char arrival_buf[XBEE_BUFFER_SIZE]; |
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// location of last unread byte in buffer |
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volatile int buffer_last = 0; |
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// first unread byte in buffer |
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volatile int buffer_first = 0; |
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|
|
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//used to store packets as they are read |
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char xbee_buf[128]; |
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int currentBufPos = 0; |
| ... | ... | |
| 127 | 133 |
|
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/** |
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* Interrupt for the robot. Adds bytes received from the xbee |
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* to the queue.
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* to the buffer.
|
|
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**/ |
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#ifndef FIREFLY |
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ISR(USART1_RX_vect) |
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{
|
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char c = UDR1; |
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queue_add(xbee_queue, (void*)(int)c); |
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arrival_buf[buffer_last] = c; |
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int t = buffer_last + 1; |
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if (t == XBEE_BUFFER_SIZE) |
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t = 0; |
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if (t == buffer_first) |
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{
|
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WL_DEBUG_PRINT("Out of space in buffer.\n");
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} |
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buffer_last = t; |
|
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} |
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#else |
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SIGNAL(SIG_USART0_RECV) |
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{
|
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char c = UDR0; |
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queue_add(xbee_queue, (void*)(int)c); |
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arrival_buf[buffer_last] = c; |
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int t = buffer_last + 1; |
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if (t == XBEE_BUFFER_SIZE) |
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t = 0; |
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if (t == buffer_first) |
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{
|
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WL_DEBUG_PRINT("Out of space in buffer.\n");
|
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} |
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buffer_last = t; |
|
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} |
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#endif |
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|
| ... | ... | |
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while (1) |
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{
|
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xbee_read(&c, 1); |
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queue_add(xbee_queue, (void*)(int)c); |
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arrival_buf[buffer_last] = c; |
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int t = buffer_last + 1; |
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if (t == XBEE_BUFFER_SIZE) |
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t = 0; |
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if (t == buffer_first) |
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{
|
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WL_DEBUG_PRINT("Out of space in buffer.\n");
|
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} |
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buffer_last = t; |
|
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} |
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return 0; |
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} |
| ... | ... | |
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**/ |
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int xbee_lib_init(void) |
| 168 | 198 |
{
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xbee_queue = queue_create(); |
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if (xbee_queue == NULL) {
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return -1; |
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} |
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|
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arrival_buf[0] = 'A'; |
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arrival_buf[1] = 'A'; |
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arrival_buf[2] = 'A'; |
|
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#ifdef ROBOT |
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|
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//enable the receiving interrupt |
| ... | ... | |
| 255 | 283 |
lockf(xbee_stream, F_ULOCK, 0); |
| 256 | 284 |
close(xbee_stream); |
| 257 | 285 |
#endif |
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queue_destroy(xbee_queue); |
|
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} |
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|
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/** |
| ... | ... | |
| 366 | 393 |
char* curr = s; |
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while (curr - s < len) |
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{
|
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if (queue_is_empty(xbee_queue)) |
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// check if buffer is empty |
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if (buffer_last == buffer_first) |
|
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continue; |
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char c = (char)(int)queue_remove(xbee_queue); |
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char c = arrival_buf[buffer_first++]; |
|
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if (buffer_first == XBEE_BUFFER_SIZE) |
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buffer_first = 0; |
|
| 372 | 402 |
if (c == *curr) |
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curr++; |
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else |
| ... | ... | |
| 576 | 606 |
if (currentBufPos == 0) |
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{
|
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do |
| 579 |
if (queue_is_empty(xbee_queue)) |
|
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{
|
|
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if (buffer_first == XBEE_BUFFER_SIZE) |
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buffer_first = 0; |
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// check if buffer is empty |
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if (buffer_first == buffer_last) |
|
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return -1; |
| 581 |
while ((char)(int)queue_remove(xbee_queue) != XBEE_FRAME_START); |
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} |
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while (arrival_buf[buffer_first++] != XBEE_FRAME_START); |
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if (buffer_first == XBEE_BUFFER_SIZE) |
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buffer_first = 0; |
|
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xbee_buf[0] = XBEE_FRAME_START; |
| 583 | 620 |
currentBufPos++; |
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} |
| ... | ... | |
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return -1; |
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} |
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} |
| 603 |
if (queue_is_empty(xbee_queue)) |
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// check if buffer is empty |
|
| 641 |
if (buffer_first == buffer_last) |
|
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return -1; |
| 605 |
xbee_buf[currentBufPos++] = (char)(int)queue_remove(xbee_queue); |
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xbee_buf[currentBufPos++] = arrival_buf[buffer_first++]; |
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if (buffer_first == XBEE_BUFFER_SIZE) |
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buffer_first = 0; |
|
| 606 | 646 |
} |
| 607 | 647 |
|
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currentBufPos = 0; |
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