critical uint16_t mac_send(uint8_t packet[], uint16_t length, uint16_t dst_addr) {
// check length
if (length>PACKET_LENGTH_MAX) {
PRINTF("mac_send length error\n");
return 2;
}
// check state
if (txframe.length != 0) {
PRINTF("mac_send already sending\n");
// already sending, can't do anything
return 1;
}
// prepare header
txframe.length = length + HEADER_LENGTH;
txframe.type = TYPE_DATA;
txframe.dst_addr[0] = dst_addr>>8;
txframe.dst_addr[1] = dst_addr & 0xFF;
txframe.src_addr[0] = node_addr>>8;
txframe.src_addr[1] = node_addr & 0xFF;
// copy packet to the local variable
memcpy(txframe.payload, packet, length);
// try to send
delay_count = 0;
tx_delay();
return 0;
}
static uint16_t retest(void)
{
stat_add(STAT_MAC_RETRY_ACK_TIMEOUT);
count_as_retry = 1;
tx_delay();
return 0;
}
static uint16_t tx_try(void) {
uint8_t status;
if (txframe.length == 0) {
PRINTF("tx_try no packet error\n");
return rx_set();
}
// if radio not in RX, delay
status = cc1101_status() & 0x70;
if ( status != 0x10) {
PRINTF("try sending radio state error (%x)\n", status);
tx_delay();
return rx_set();
}
// if there are some weird bytes in TX FIFO, flush everything
if (cc1101_status_txbytes()!=0) {
PRINTF("mac had to flush\n");
cc1101_cmd_idle();
cc1101_cmd_flush_tx();
cc1101_cmd_flush_rx();
}
// try to send
cc1101_cmd_tx();
// get chip status
status = cc1101_status() & 0x70;
// if status is not RX
if ( status != 0x10) {
// put data in fifo
cc1101_fifo_put((uint8_t*)&txframe, txframe.length+1);
cc1101_gdo0_register_callback(tx_done);
} else {
tx_delay();
rx_set();
}
return 0;
}
