/// build the timing table
static void
tdm_build_timing_table(void)
{
__pdata uint8_t j;
__pdata uint16_t rate;
bool golay_saved = feature_golay;
feature_golay = false;
for (rate=2; rate<256; rate=(rate*3)/2) {
__pdata uint32_t latency_sum=0, per_byte_sum=0;
uint8_t size = MAX_PACKET_LENGTH;
radio_configure(rate);
for (j=0; j<50; j++) {
__pdata uint16_t time_0, time_max, t1, t2;
radio_set_channel(1);
radio_receiver_on();
if (serial_read_available() > 0) {
feature_golay = golay_saved;
return;
}
t1 = timer2_tick();
if (!radio_transmit(0, pbuf, 0xFFFF)) {
break;
}
t2 = timer2_tick();
radio_receiver_on();
time_0 = t2-t1;
radio_set_channel(2);
t1 = timer2_tick();
if (!radio_transmit(size, pbuf, 0xFFFF)) {
if (size == 0) {
break;
}
size /= 4;
j--;
continue;
}
t2 = timer2_tick();
radio_receiver_on();
time_max = t2-t1;
latency_sum += time_0;
per_byte_sum += ((size/2) + (time_max - time_0))/size;
}
if (j > 0) {
printf("{ %u, %u, %u },\n",
(unsigned)(radio_air_rate()),
(unsigned)(latency_sum/j),
(unsigned)(per_byte_sum/j));
}
}
feature_golay = golay_saved;
}
void radio_init()
{
Mirf.spi = &MirfHardwareSpi;
Mirf.init();
Mirf.setRADDR((uint8_t *)RECEIVE_ADDRESS);
Mirf.payload = sizeof(radio_packet_t);
int channel = settings_get_channel();
radio_set_channel(channel, true);
}
int
cmd_handler_cooja(const uint8_t *data, int len)
{
if(data[0] == '!') {
if(data[1] == 'C' && len == 3) {
printf("cooja_cmd: setting channel: %d\n", data[2]);
radio_set_channel(data[2]);
//Enable radio
NETSTACK_RDC.off(1);
return 1;
} else if(data[1] == 'M' && len == 10) {
if(!linkaddr_cmp((linkaddr_t *)(data+2), &linkaddr_null)) {
printf("cooja_cmd: Got MAC\n");
if(linkaddr_cmp(&default_link_addr, &linkaddr_null)) {
linkaddr_copy(&default_link_addr, &linkaddr_node_addr);
}
memcpy(uip_lladdr.addr, data+2, sizeof(uip_lladdr.addr));
linkaddr_set_node_addr((linkaddr_t *) uip_lladdr.addr);
} else {
printf("cooja_cmd: Clear MAC disabled\n");
if(!linkaddr_cmp(&default_link_addr, &linkaddr_null)) {
memcpy(uip_lladdr.addr, &default_link_addr, sizeof(uip_lladdr.addr));
linkaddr_set_node_addr(&default_link_addr);
}
//Stop radio
NETSTACK_RDC.off(0);
}
return 1;
}
} else if(data[0] == '?') {
if(data[1] == 'C' && len == 2) {
uint8_t buf[4];
printf("cooja_cmd: getting channel: %d\n", data[2]);
buf[0] = '!';
buf[1] = 'C';
buf[2] = 0;
cmd_send(buf, 3);
return 1;
}
}
return 0;
}
static void
radio_init(void)
{
__pdata uint32_t freq_min, freq_max;
__pdata uint32_t channel_spacing;
__pdata uint8_t txpower;
// Do generic PHY initialisation
if (!radio_initialise()) {
panic("radio_initialise failed");
}
switch (g_board_frequency) {
case FREQ_433:
freq_min = 433050000UL;
freq_max = 434790000UL;
txpower = 10;
num_fh_channels = 10;
break;
case FREQ_470:
freq_min = 470000000UL;
freq_max = 471000000UL;
txpower = 10;
num_fh_channels = 10;
break;
case FREQ_868:
freq_min = 868000000UL;
freq_max = 869000000UL;
txpower = 10;
num_fh_channels = 10;
break;
case FREQ_915:
freq_min = 915000000UL;
freq_max = 928000000UL;
txpower = 20;
num_fh_channels = MAX_FREQ_CHANNELS;
break;
default:
freq_min = 0;
freq_max = 0;
txpower = 0;
panic("bad board frequency %d", g_board_frequency);
break;
}
if (param_get(PARAM_NUM_CHANNELS) != 0) {
num_fh_channels = param_get(PARAM_NUM_CHANNELS);
}
if (param_get(PARAM_MIN_FREQ) != 0) {
freq_min = param_get(PARAM_MIN_FREQ) * 1000UL;
}
if (param_get(PARAM_MAX_FREQ) != 0) {
freq_max = param_get(PARAM_MAX_FREQ) * 1000UL;
}
if (param_get(PARAM_TXPOWER) != 0) {
txpower = param_get(PARAM_TXPOWER);
}
// constrain power and channels
txpower = constrain(txpower, BOARD_MINTXPOWER, BOARD_MAXTXPOWER);
num_fh_channels = constrain(num_fh_channels, 1, MAX_FREQ_CHANNELS);
// double check ranges the board can do
switch (g_board_frequency) {
case FREQ_433:
freq_min = constrain(freq_min, 414000000UL, 460000000UL);
freq_max = constrain(freq_max, 414000000UL, 460000000UL);
break;
case FREQ_470:
freq_min = constrain(freq_min, 450000000UL, 490000000UL);
freq_max = constrain(freq_max, 450000000UL, 490000000UL);
break;
case FREQ_868:
freq_min = constrain(freq_min, 849000000UL, 889000000UL);
freq_max = constrain(freq_max, 849000000UL, 889000000UL);
break;
case FREQ_915:
freq_min = constrain(freq_min, 868000000UL, 935000000UL);
freq_max = constrain(freq_max, 868000000UL, 935000000UL);
break;
default:
panic("bad board frequency %d", g_board_frequency);
break;
}
if (freq_max == freq_min) {
freq_max = freq_min + 1000000UL;
}
// get the duty cycle we will use
duty_cycle = param_get(PARAM_DUTY_CYCLE);
duty_cycle = constrain(duty_cycle, 0, 100);
param_set(PARAM_DUTY_CYCLE, duty_cycle);
// get the LBT threshold we will use
lbt_rssi = param_get(PARAM_LBT_RSSI);
if (lbt_rssi != 0) {
// limit to the RSSI valid range
lbt_rssi = constrain(lbt_rssi, 25, 220);
}
param_set(PARAM_LBT_RSSI, lbt_rssi);
// sanity checks
param_set(PARAM_MIN_FREQ, freq_min/1000);
param_set(PARAM_MAX_FREQ, freq_max/1000);
param_set(PARAM_NUM_CHANNELS, num_fh_channels);
channel_spacing = (freq_max - freq_min) / (num_fh_channels+2);
// add half of the channel spacing, to ensure that we are well
// away from the edges of the allowed range
freq_min += channel_spacing/2;
// add another offset based on network ID. This means that
// with different network IDs we will have much lower
// interference
srand(param_get(PARAM_NETID));
if (num_fh_channels > 5) {
freq_min += ((unsigned long)(rand()*625)) % channel_spacing;
}
debug("freq low=%lu high=%lu spacing=%lu\n",
freq_min, freq_min+(num_fh_channels*channel_spacing),
channel_spacing);
// set the frequency and channel spacing
// change base freq based on netid
radio_set_frequency(freq_min);
// set channel spacing
radio_set_channel_spacing(channel_spacing);
// start on a channel chosen by network ID
radio_set_channel(param_get(PARAM_NETID) % num_fh_channels);
// And intilise the radio with them.
if (!radio_configure(param_get(PARAM_AIR_SPEED)) &&
!radio_configure(param_get(PARAM_AIR_SPEED)) &&
!radio_configure(param_get(PARAM_AIR_SPEED))) {
panic("radio_configure failed");
}
// report the real air data rate in parameters
param_set(PARAM_AIR_SPEED, radio_air_rate());
// setup network ID
radio_set_network_id(param_get(PARAM_NETID));
// setup transmit power
radio_set_transmit_power(txpower);
// report the real transmit power in settings
param_set(PARAM_TXPOWER, radio_get_transmit_power());
#ifdef USE_RTC
// initialise real time clock
rtc_init();
#endif
// initialise frequency hopping system
fhop_init(param_get(PARAM_NETID));
// initialise TDM system
tdm_init();
}
/// main loop for time division multiplexing transparent serial
///
void
tdm_serial_loop(void)
{
__pdata uint16_t last_t = timer2_tick();
__pdata uint16_t last_link_update = last_t;
_canary = 42;
for (;;) {
__pdata uint8_t len;
__pdata uint16_t tnow, tdelta;
__pdata uint8_t max_xmit;
if (_canary != 42) {
panic("stack blown\n");
}
if (pdata_canary != 0x41) {
panic("pdata canary changed\n");
}
// give the AT command processor a chance to handle a command
at_command();
// display test data if needed
if (test_display) {
display_test_output();
test_display = 0;
}
if (seen_mavlink && feature_mavlink_framing && !at_mode_active) {
seen_mavlink = false;
MAVLink_report();
}
// set right receive channel
radio_set_channel(fhop_receive_channel());
// get the time before we check for a packet coming in
tnow = timer2_tick();
// see if we have received a packet
if (radio_receive_packet(&len, pbuf)) {
// update the activity indication
received_packet = true;
fhop_set_locked(true);
// update filtered RSSI value and packet stats
statistics.average_rssi = (radio_last_rssi() + 7*(uint16_t)statistics.average_rssi)/8;
statistics.receive_count++;
// we're not waiting for a preamble
// any more
transmit_wait = 0;
if (len < 2) {
// not a valid packet. We always send
// two control bytes at the end of every packet
continue;
}
// extract control bytes from end of packet
memcpy(&trailer, &pbuf[len-sizeof(trailer)], sizeof(trailer));
len -= sizeof(trailer);
if (trailer.window == 0 && len != 0) {
// its a control packet
if (len == sizeof(struct statistics)) {
memcpy(&remote_statistics, pbuf, len);
}
// don't count control packets in the stats
statistics.receive_count--;
} else if (trailer.window != 0) {
// sync our transmit windows based on
// received header
sync_tx_windows(len);
last_t = tnow;
if (trailer.command == 1) {
handle_at_command(len);
} else if (len != 0 &&
!packet_is_duplicate(len, pbuf, trailer.resend) &&
!at_mode_active) {
// its user data - send it out
// the serial port
//printf("rcv(%d,[", len);
LED_ACTIVITY = LED_ON;
serial_write_buf(pbuf, len);
LED_ACTIVITY = LED_OFF;
//printf("]\n");
}
}
continue;
}
// see how many 16usec ticks have passed and update
// the tdm state machine. We re-fetch tnow as a bad
// packet could have cost us a lot of time.
tnow = timer2_tick();
tdelta = tnow - last_t;
tdm_state_update(tdelta);
last_t = tnow;
// update link status every 0.5s
if (tnow - last_link_update > 32768) {
link_update();
last_link_update = tnow;
}
if (lbt_rssi != 0) {
// implement listen before talk
if (radio_current_rssi() < lbt_rssi) {
lbt_listen_time += tdelta;
} else {
lbt_listen_time = 0;
if (lbt_rand == 0) {
lbt_rand = ((uint16_t)rand()) % lbt_min_time;
}
}
if (lbt_listen_time < lbt_min_time + lbt_rand) {
// we need to listen some more
continue;
}
}
// we are allowed to transmit in our transmit window
// or in the other radios transmit window if we have
// bonus ticks
#if USE_TICK_YIELD
if (tdm_state != TDM_TRANSMIT &&
!(bonus_transmit && tdm_state == TDM_RECEIVE)) {
// we cannot transmit now
continue;
}
#else
if (tdm_state != TDM_TRANSMIT) {
continue;
}
#endif
if (transmit_yield != 0) {
// we've give up our window
continue;
}
if (transmit_wait != 0) {
// we're waiting for a preamble to turn into a packet
continue;
}
if (!received_packet &&
radio_preamble_detected() ||
radio_receive_in_progress()) {
// a preamble has been detected. Don't
// transmit for a while
transmit_wait = packet_latency;
continue;
}
// sample the background noise when it is out turn to
// transmit, but we are not transmitting,
// averaged over around 4 samples
statistics.average_noise = (radio_current_rssi() + 3*(uint16_t)statistics.average_noise)/4;
if (duty_cycle_wait) {
// we're waiting for our duty cycle to drop
continue;
}
// how many bytes could we transmit in the time we
// have left?
if (tdm_state_remaining < packet_latency) {
// none ....
continue;
}
max_xmit = (tdm_state_remaining - packet_latency) / ticks_per_byte;
if (max_xmit < PACKET_OVERHEAD) {
// can't fit the trailer in with a byte to spare
continue;
}
max_xmit -= PACKET_OVERHEAD;
if (max_xmit > max_data_packet_length) {
max_xmit = max_data_packet_length;
}
// ask the packet system for the next packet to send
if (send_at_command &&
max_xmit >= strlen(remote_at_cmd)) {
// send a remote AT command
len = strlen(remote_at_cmd);
memcpy(pbuf, remote_at_cmd, len);
trailer.command = 1;
send_at_command = false;
} else {
// get a packet from the serial port
memset(pbuf, 0x40, 16);
len = packet_get_next(max_xmit-16, pbuf+16) + 16;
trailer.command = packet_is_injected();
if (len == 16)
len = 0;
}
if (len > max_data_packet_length) {
panic("oversized tdm packet");
}
trailer.bonus = (tdm_state == TDM_RECEIVE);
trailer.resend = packet_is_resend();
if (tdm_state == TDM_TRANSMIT &&
len == 0 &&
send_statistics &&
max_xmit >= sizeof(statistics)) {
// send a statistics packet
send_statistics = 0;
memcpy(pbuf, &statistics, sizeof(statistics));
len = sizeof(statistics);
// mark a stats packet with a zero window
trailer.window = 0;
trailer.resend = 0;
} else {
// calculate the control word as the number of
// 16usec ticks that will be left in this
// tdm state after this packet is transmitted
trailer.window = (uint16_t)(tdm_state_remaining - flight_time_estimate(len+sizeof(trailer)));
}
// set right transmit channel
radio_set_channel(fhop_transmit_channel());
memcpy(&pbuf[len], &trailer, sizeof(trailer));
if (len != 0 && trailer.window != 0) {
// show the user that we're sending real data
LED_ACTIVITY = LED_ON;
}
if (len == 0) {
// sending a zero byte packet gives up
// our window, but doesn't change the
// start of the next window
transmit_yield = 1;
}
// after sending a packet leave a bit of time before
// sending the next one. The receivers don't cope well
// with back to back packets
transmit_wait = packet_latency;
// if we're implementing a duty cycle, add the
// transmit time to the number of ticks we've been transmitting
if ((duty_cycle - duty_cycle_offset) != 100) {
transmitted_ticks += flight_time_estimate(len+sizeof(trailer));
}
// start transmitting the packet
if (!radio_transmit(len + sizeof(trailer), pbuf, tdm_state_remaining + (silence_period/2)) &&
len != 0 && trailer.window != 0 && trailer.command == 0) {
packet_force_resend();
}
if (lbt_rssi != 0) {
// reset the LBT listen time
lbt_listen_time = 0;
lbt_rand = 0;
}
// set right receive channel
radio_set_channel(fhop_receive_channel());
// re-enable the receiver
radio_receiver_on();
if (len != 0 && trailer.window != 0) {
LED_ACTIVITY = LED_OFF;
}
}
}