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crc calculation contributed by Carlo Alberto Buano + some refactoring.

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This commit is contained in:
nvt-se 2008-11-11 12:24:43 +00:00
parent 93b32243d0
commit 90691eb6a2
1 changed files with 67 additions and 21 deletions
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88
platform/msb430/dev/cc1020.c
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@ -57,11 +57,14 @@ Berlin, 2006
#include "cc1020-internal.h"
#include "cc1020.h"
#include "lib/random.h"
#include "lib/crc16.h"
#include "net/rime/rimestats.h"
#include "dev/irq.h"
#include "dev/dma.h"
#include "energest.h"
#define CRC_LEN 2 // CHECKSUM
static int cc1020_calibrate(void);
static int cc1020_setupTX(int);
static int cc1020_setupRX(int);
@ -113,6 +116,20 @@ dma_callback(void)
dma_done = 1;
}
static
reset_receiver(void)
{
// reset receiver
cc1020_rxlen = 0;
if ((cc1020_state & CC1020_TURN_OFF) && (cc1020_txlen == 0)) {
cc1020_off();
} else {
CC1020_SET_OPSTATE(CC1020_RX | CC1020_RX_SEARCHING);
ENABLE_RX_IRQ();
}
}
void
cc1020_init(const uint8_t *config)
{
@ -214,8 +231,10 @@ cc1020_set_power(uint8_t pa_power)
int
cc1020_send(const void *buf, unsigned short len)
{
int try;
int try;
int normal_header = HDRSIZE + len;
uint16_t rxcrc = 0xFFFF; // For checksum purposes
if (cc1020_state == CC1020_OFF)
return -2;
@ -226,16 +245,29 @@ cc1020_send(const void *buf, unsigned short len)
cc1020_txlen = PREAMBLESIZE + SYNCWDSIZE;
// header
cc1020_txbuf[cc1020_txlen++] = 0x00;
cc1020_txbuf[cc1020_txlen++] = HDRSIZE + len;
cc1020_txbuf[cc1020_txlen++] = 0x00;
cc1020_txbuf[cc1020_txlen++] = normal_header + CRC_LEN;
// Adding the checksum on header and data
rxcrc = crc16_add((uint8_t) (normal_header & 0xff), rxcrc);
rxcrc = crc16_add((uint8_t) ((normal_header >> 8)& 0xff), rxcrc);
int i=0;
for(i=0;i<len;i++){
rxcrc = crc16_add((uint8_t) ((char*)buf)[i], rxcrc);
}
// data to send
memcpy((char *)cc1020_txbuf + cc1020_txlen, buf, len);
cc1020_txlen += len;
// Send checksum
memcpy((char *)cc1020_txbuf + cc1020_txlen, &rxcrc, CRC_LEN);
cc1020_txlen += CRC_LEN;
// suffix
cc1020_txbuf[cc1020_txlen++] = TAIL;
cc1020_txbuf[cc1020_txlen++] = TAIL;
cc1020_txbuf[cc1020_txlen++] = TAIL;
// Wait for the medium to become idle.
if (cc1020_carrier_sense()) {
@ -292,15 +324,7 @@ cc1020_read(void *buf, unsigned short size)
memcpy(buf, (char *)cc1020_rxbuf + HDRSIZE, len);
RIMESTATS_ADD(llrx);
// reset receiver
cc1020_rxlen = 0;
if ((cc1020_state & CC1020_TURN_OFF) && (cc1020_txlen == 0)) {
cc1020_off();
} else {
CC1020_SET_OPSTATE(CC1020_RX | CC1020_RX_SEARCHING);
ENABLE_RX_IRQ();
}
reset_receiver();
return len;
}
@ -370,10 +394,30 @@ PROCESS_THREAD(cc1020_receiver_process, ev, data)
while(1) {
ev = PROCESS_EVENT_NONE;
PROCESS_YIELD_UNTIL(ev == PROCESS_EVENT_POLL);
PROCESS_YIELD_UNTIL(ev == PROCESS_EVENT_POLL);
if(receiver_callback != NULL) {
receiver_callback(&cc1020_driver);
// CHECKSUM CHECK
uint16_t expected_crc = 0xffff;
uint16_t actual_crc = -1;
memcpy(&actual_crc, &cc1020_rxbuf[cc1020_rxlen - CRC_LEN], CRC_LEN);
cc1020_rxlen -= CRC_LEN;
expected_crc = crc16_add((uint8_t) (cc1020_rxlen & 0xff), expected_crc);
expected_crc = crc16_add((uint8_t) ((cc1020_rxlen >> 8) & 0xff),
expected_crc);
int i = 0;
for(i = HDRSIZE; i < cc1020_rxlen; i++){
expected_crc = crc16_add(cc1020_rxbuf[i], expected_crc);
}
if(expected_crc == actual_crc){
receiver_callback(&cc1020_driver);
} else {
RIMESTATS_ADD(badcrc);
reset_receiver();
}
}
}
@ -430,9 +474,10 @@ interrupt(UART0RX_VECTOR) cc1020_rxhandler(void)
} else {
return;
}
/* Update RSSI.
TODO: add sampling/averaging of several RSSI to get
more reliable RSSI values
/*
* Update RSSI.
* TODO: add sampling/averaging of several RSSI to get
* more reliable RSSI values.
*/
rssi = cc1020_read_reg(CC1020_RSS);
CC1020_SET_OPSTATE(CC1020_RX | CC1020_RX_RECEIVING);
@ -452,6 +497,7 @@ interrupt(UART0RX_VECTOR) cc1020_rxhandler(void)
}
cc1020_rxlen++;
if (cc1020_rxlen == HDRSIZE) {
pktlen = ((struct cc1020_header *)cc1020_rxbuf)->length;
if (pktlen == 0 || pktlen > sizeof (cc1020_rxbuf)) {