Revision 1612
Updated basic receive function and wrote handler dispatch function. The latter doesn't compile, but most of this directory doesn't.
| branches/wireless/code/projects/libwireless/wireless_receive.c | ||
|---|---|---|
| 60 | 60 |
extern uint8_t basic_buf_last; // end of last packet in basic buffer |
| 61 | 61 |
extern uint8_t other_buf_first; // beginning of first packet in other buffer |
| 62 | 62 |
extern uint8_t other_buf_last; // end of last packet in other buffer |
| 63 |
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// the receive functions |
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extern void (*handlers[])(void); // array of pointers to normal-priority packet handlers |
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/** |
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* @addtogroup wireless Wireless |
| ... | ... | |
| 98 | 96 |
**/ |
| 99 | 97 |
int8_t wl_get_basic(char *data, uint8_t length) {
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| 100 | 98 |
uint8_t buf_pos = basic_buf_first; // start at beginning of first (oldest) basic packet |
| 101 |
uint8_t data_length = xbee_basic_buf[buf_pos]; // get packet length |
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uint8_t packet_num; // number of packet (may eventually be used to weed out duplicates) |
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uint8_t data_length = xbee_basic_buf[buf_pos % PACKET_BUFFER_SIZE]; // get packet length |
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| 103 | 100 |
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if (data_length > length) // not enough room for packet in destination
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if (data_length - 3 > length) // not enough room for data in destination
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return WL_ERROR_TOO_SMALL; |
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// packet has not fully arrived yet |
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if (buf_pos + data_length > basic_buf_last // length goes farther than end of buffer |
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&& !(buf_pos >= basic_buf_last && buf_pos + data_length > buf_pos)) |
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/* basic test is Beginning + Length > Buffer End means packet isn't all there yet |
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if end counter overflows, a complete packet's end may still be greater than the buffer end index, |
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but such a packet can be read from the buffer |
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*/ |
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return WL_SUCCESS; // no data written |
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buf_pos++; |
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packet_num = xbee_basic_buf[buf_pos]; // get packet number |
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buf_pos++; |
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buf_pos++; // ignore the group code. it will always be the same. |
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buf_pos++; // ignore the source ID |
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memcpy(data, xbee_basic_buf + buf_pos, data_length); // get the data |
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// copy data to destination, byte by byte to account for circular buffer |
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// don't copy the 3 header bytes. nobody wants those. |
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for (; buf_pos < basic_buf_first + data_length; buf_pos++) |
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memcpy(data + buf_pos - 3, xbee_basic_buf + (buf_pos % PACKET_BUFFER_SIZE), 1); |
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basic_buf_first += data_length; // "free up" this packet's buffer space |
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return 0;
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return data_length;
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} |
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/* |
| ... | ... | |
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* @return error codes (TBD) |
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*/ |
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int8_t wl_dispatch(void) {
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uint8_t buf_pos = other_buf_first; // current position in buffer |
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uint8_t group; // group of packet under consideration |
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void (*handler)(uint8_t *data, uint8_t length, uint8_t source); // handler for group of packet under consideration |
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uint8_t length = xbee_other_buf[buf_pos % PACKET_BUFFER_SIZE]; // length of packet under consideration |
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uint8_t source; // robot ID of sender of packet under consideration |
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return 0; |
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// consider packets one at a time until buffer contains no complete packets |
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while (buf_pos + length <= other_buf_last // length goes farther than end of buffer |
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|| (buf_pos >= other_buf_last && buf_pos + length > buf_pos)) {
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/* basic test is Beginning + Length > Buffer End means packet isn't all there yet |
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if end counter overflows, a complete packet's end may still be greater than the buffer end index, |
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but such a packet can be read from the buffer |
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*/ |
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buf_pos++; |
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group = xbee_other_buf[buf_pos]; // get group from packet |
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if (group >= WL_NUM_PACKET_GROUPS) // invalid group number |
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buf_pos += length - 1 + 1; // go to first byte of next packet |
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else { // valid group number
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handler = handlers[group].FUNC; // get function from handler array |
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buf_pos++; |
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buf_pos++; // ignore 1st byte of ID (will be all 0s) |
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source = xbee_other_buf[buf_pos]; // get sender ID from packet |
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buf_pos++; // now index of beginning of packet data (mod PACKET_BUFFER_SIZE) |
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if (handler) // check whether group is handled |
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(*handler)(xbee_other_buf + (buf_pos & PACKET_BUFFER_SIZE), length - 4, source); |
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// go to next packet |
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buf_pos += length - 4 + 1; // go to first byte of next packet |
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} |
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length = xbee_other_buf[buf_pos & PACKET_BUFFER_SIZE]; // get length of next packet |
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} |
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return WL_SUCCESS; |
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| 126 | 167 |
} |
| 127 | 168 |
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| branches/wireless/code/projects/libwireless/wireless.c | ||
|---|---|---|
| 44 | 44 |
* @{
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**/ |
| 46 | 46 |
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static uint8_t init_flag = INIT_NO; |
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static PacketGroupHandler wl_packet_handlers[MAX_PACKET_GROUPS]; |
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/* holds pointers to all normal-priority packet handlers |
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group handler located at index of group number |
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group numbers with handlers undefined are NULL |
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*/ |
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void (*handlers[WL_NUM_PACKET_GROUPS])(void); |
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/** |
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* initialization function: |
Also available in: Unified diff