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OP-932 Changes the RFM22 frequency hopping to change channels every Tx period. Also increases the Tx clock period from 8ms to 16ms, and adds a check on calculation the the time delta that it doesn't change the previous estimated time delta by too much. If the delta between the current time delta and the previously estimated time delta is too large it could indicate that there was a delay somewhere that makes the calculated time delta inaccurate.

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Rearanges the packet send priority in the rfm22b driver so that PPM packets are top priority.
This commit is contained in:
Brian Webb 2013-05-20 18:21:07 -07:00
parent 0798d8e330
commit d4a4588011
2 changed files with 81 additions and 68 deletions
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97
flight/pios/common/pios_rfm22b.c
View File

@ -85,7 +85,7 @@
#define MAX_RADIOSTATS_MISS_COUNT 3
// The time between PPM updates
#define PPM_UPDATE_PERIOD_MS 20
#define PPM_UPDATE_PERIOD_MS 30
// this is too adjust the RF module so that it is on frequency
#define OSC_LOAD_CAP 0x7F // cap = 12.5pf .. default
@ -1375,6 +1375,8 @@ static enum pios_radio_event rfm22_init(struct pios_rfm22b_dev *rfm22b_dev)
rfm22b_dev->destination_id = 0xffffffff;
rfm22b_dev->send_status = false;
rfm22b_dev->send_connection_request = false;
rfm22b_dev->send_ack_nack = false;
rfm22b_dev->resend_packet = false;
// Initialize the packets.
rfm22b_dev->rx_packet_len = 0;
@ -1801,12 +1803,29 @@ static enum pios_radio_event radio_txStart(struct pios_rfm22b_dev *radio_dev)
return RADIO_EVENT_RX_MODE;
}
// See if there's a packet ready to send.
if (radio_dev->tx_packet) {
p = radio_dev->tx_packet;
} else {
// Don't send a packet if we're waiting for an ACK
if (radio_dev->prev_tx_packet) {
#ifdef PIOS_PPM_RECEIVER
// Send a PPM packet?
if (radio_dev->send_ppm) {
p = (PHPacketHandle) & (radio_dev->ppm_packet);
radio_dev->send_ppm = false;
}
#endif
// Send an ACK/NACK?
if (!p && radio_dev->send_ack_nack) {
p = (PHPacketHandle) & (radio_dev->ack_nack_packet);
radio_dev->send_ack_nack = false;
}
// Resend a packet?
if (!p && radio_dev->resend_packet) {
p = radio_dev->prev_tx_packet;
radio_dev->prev_tx_packet = NULL;
radio_dev->resend_packet = false;
}
// Don't send another packet if we're waiting for an ACK.
if (!p && radio_dev->prev_tx_packet) {
return RADIO_EVENT_RX_MODE;
}
@ -1816,20 +1835,6 @@ static enum pios_radio_event radio_txStart(struct pios_rfm22b_dev *radio_dev)
radio_dev->send_connection_request = false;
}
#ifdef PIOS_PPM_RECEIVER
// Send a PPM packet?
if (!p && radio_dev->send_ppm) {
p = (PHPacketHandle) & (radio_dev->ppm_packet);
radio_dev->send_ppm = false;
}
#endif
// Send status?
if (!p && radio_dev->send_status) {
p = (PHPacketHandle) & (radio_dev->status_packet);
radio_dev->send_status = false;
}
// Try to get some data to send
if (!p) {
bool need_yield = false;
@ -1848,7 +1853,13 @@ static enum pios_radio_event radio_txStart(struct pios_rfm22b_dev *radio_dev)
p = NULL;
}
}
// Send status?
if (!p && radio_dev->send_status) {
p = (PHPacketHandle) & (radio_dev->status_packet);
radio_dev->send_status = false;
}
if (!p) {
return RADIO_EVENT_RX_MODE;
}
@ -1902,9 +1913,10 @@ static enum pios_radio_event radio_txData(struct pios_rfm22b_dev *radio_dev)
if (radio_dev->rx_packet.header.type == PACKET_TYPE_CON_REQUEST) {
rfm22_setConnectionParameters(radio_dev);
}
} else if ((radio_dev->tx_packet->header.type != PACKET_TYPE_NACK) && (radio_dev->tx_packet->header.type != PACKET_TYPE_PPM) &&
(radio_dev->tx_packet->header.type != PACKET_TYPE_STATUS) && (radio_dev->tx_packet->header.type != PACKET_TYPE_PPM)) {
// We need to wait for an ACK if this packet it not an ACK, NACK, or PPM.
} else if ((radio_dev->tx_packet->header.type != PACKET_TYPE_NACK) &&
(radio_dev->tx_packet->header.type != PACKET_TYPE_PPM) &&
(radio_dev->tx_packet->header.type != PACKET_TYPE_STATUS)) {
// We need to wait for an ACK if this packet it not an ACK, NACK, PPM, or status packet.
radio_dev->prev_tx_packet = radio_dev->tx_packet;
}
radio_dev->tx_packet = 0;
@ -2058,7 +2070,11 @@ static enum pios_radio_event radio_receivePacket(struct pios_rfm22b_dev *radio_d
if (seq_num == (prev_seq_num + 1)) {
portTickType local_rx_time = radio_dev->rx_complete_ticks;
portTickType remote_tx_time = radio_dev->rx_packet.header.prev_tx_time;
portTickType time_delta = remote_tx_time - local_rx_time;
portTickType time_delta_delta = (time_delta > radio_dev->time_delta) ? (time_delta - radio_dev->time_delta) : (radio_dev->time_delta - time_delta);
if (time_delta_delta <= 2) {
radio_dev->time_delta = remote_tx_time - local_rx_time;
}
} else if (seq_num > prev_seq_num) {
// Add any missed packets into the stats.
uint16_t missed_packets = seq_num - prev_seq_num - 1;
@ -2130,8 +2146,8 @@ static enum pios_radio_event radio_rxData(struct pios_rfm22b_dev *radio_dev)
*/
static void rfm22_sendStatus(struct pios_rfm22b_dev *rfm22b_dev)
{
// Don't send if a status is already queued.
if (rfm22b_dev->send_status) {
// Don't send if a status is already queued or if we're the coordinator and not connected.
if (rfm22b_dev->send_status || (rfm22b_dev->coordinator && !rfm22_isConnected(rfm22b_dev))) {
return;
}
@ -2205,7 +2221,7 @@ static enum pios_radio_event rfm22_sendAck(struct pios_rfm22b_dev *rfm22b_dev)
aph->header.destination_id = rfm22b_dev->destination_id;
aph->header.type = PACKET_TYPE_ACK;
aph->header.data_size = PH_ACK_NACK_DATA_SIZE(aph);
rfm22b_dev->tx_packet = (PHPacketHandle)aph;
rfm22b_dev->send_ack_nack = true;
}
return RADIO_EVENT_TX_START;
}
@ -2220,10 +2236,13 @@ static enum pios_radio_event rfm22_sendNack(struct pios_rfm22b_dev *rfm22b_dev)
{
PHAckNackPacketHandle aph = (PHAckNackPacketHandle)(&(rfm22b_dev->ack_nack_packet));
// We don't NACK PPM or status packets.
if ((rfm22b_dev->rx_packet.header.type != PACKET_TYPE_PPM) && (rfm22b_dev->rx_packet.header.type != PACKET_TYPE_STATUS)) {
aph->header.destination_id = rfm22b_dev->destination_id;
aph->header.type = PACKET_TYPE_NACK;
aph->header.data_size = PH_ACK_NACK_DATA_SIZE(aph);
rfm22b_dev->tx_packet = (PHPacketHandle)aph;
rfm22b_dev->send_ack_nack = true;
}
return RADIO_EVENT_TX_START;
}
@ -2462,9 +2481,6 @@ static void rfm22_setConnectionParameters(struct pios_rfm22b_dev *rfm22b_dev)
*/
static enum pios_radio_event rfm22_acceptConnection(struct pios_rfm22b_dev *rfm22b_dev)
{
// Set our connection state to connected
rfm22b_dev->stats.link_state = OPLINKSTATUS_LINKSTATE_CONNECTED;
// Copy the connection packet
PHConnectionPacketHandle cph = (PHConnectionPacketHandle)(&(rfm22b_dev->rx_packet));
PHConnectionPacketHandle lcph = (PHConnectionPacketHandle)(&(rfm22b_dev->con_packet));
@ -2509,11 +2525,9 @@ static portTickType rfm22_coordinatorTime(struct pios_rfm22b_dev *rfm22b_dev, po
static bool rfm22_timeToSend(struct pios_rfm22b_dev *rfm22b_dev)
{
portTickType time = rfm22_coordinatorTime(rfm22b_dev, xTaskGetTickCount());
// Divide time into 8ms blocks. Coordinator sends in firs 2 ms, and remote send in 5th and 6th ms.
bool tts = (rfm22b_dev->coordinator) ? ((time & 0x06) == 0) : (((time + 4) & 0x06) == 0);
// Noone starts a transmit just prior to a channel change.
return tts && ((time & 0x7e) < 0x7b);
// Divide time into 8ms blocks. Coordinator sends in first 2 ms, and remote send in 5th and 6th ms.
// Channel changes occur in the last 2 ms.
return (rfm22b_dev->coordinator) ? ((time & 0x0C) == 0) : (((time + 8) & 0x0C) == 0);
}
/**
@ -2524,13 +2538,10 @@ static bool rfm22_timeToSend(struct pios_rfm22b_dev *rfm22b_dev)
static uint8_t rfm22_calcChannel(struct pios_rfm22b_dev *rfm22b_dev)
{
portTickType time = rfm22_coordinatorTime(rfm22b_dev, xTaskGetTickCount());
// We change channels every 128 ms.
uint16_t n = (time >> 7) & 0xffff;
// The channel is calculated using the 16 bit CRC as the pseudo random number generator.
n = PIOS_CRC16_updateByte(n, 0);
float num_channels = rfm22b_dev->num_channels;
return (uint8_t)(num_channels * (float)n / (float)0xffff);
// Divide time into 8ms blocks. Coordinator sends in first 2 ms, and remote send in 5th and 6th ms.
// Channel changes occur in the last 2 ms.
uint8_t n = (((time + 0x0C) >> 4) & 0xff);
return PIOS_CRC_updateByte(0, n) % rfm22b_dev->num_channels;
}
/**

2
flight/pios/inc/pios_rfm22b_priv.h
View File

@ -794,6 +794,8 @@ struct pios_rfm22b_dev {
bool send_status;
bool send_ppm;
bool send_connection_request;
bool send_ack_nack;
bool resend_packet;
// The initial frequency
uint32_t init_frequency;