boolean RF22ReliableDatagram::sendtoWait(uint8_t* buf, uint8_t len, uint8_t address) { // Assemble the message uint8_t thisSequenceNumber = ++_lastSequenceNumber; Timer t; uint8_t retries = 0; while (retries++ <= _retries) { setHeaderId(thisSequenceNumber); setHeaderFlags(0); sendto(buf, len, address); waitPacketSent(3000); // Never wait for ACKS to broadcasts: if (address == RF22_BROADCAST_ADDRESS) return true; if (retries > 1) _retransmissions++; t.start(); unsigned long thisSendTime = t.read_ms(); // Timeout does not include original transmit time // Compute a new timeout, random between _timeout and _timeout*2 // This is to prevent collisions on every retransmit // if 2 nodes try to transmit at the same time uint16_t timeout = _timeout + (_timeout * (rand() % 100) / 100); while (t.read_ms() < (thisSendTime + timeout)) { if (available()) { clearRxBuf(); // Not using recv, so clear it ourselves uint8_t from = headerFrom(); uint8_t to = headerTo(); uint8_t id = headerId(); uint8_t flags = headerFlags(); // Now have a message: is it our ACK? if ( from == address && to == _thisAddress && (flags & RF22_FLAGS_ACK) && (id == thisSequenceNumber)) { // Its the ACK we are waiting for return true; } else if ( !(flags & RF22_FLAGS_ACK) && (id == _seenIds[from])) { // This is a request we have already received. ACK it again acknowledge(id, from); } // Else discard it } // Not the one we are waiting for, maybe keep waiting until timeout exhausted } // Timeout exhausted, maybe retry } return false; }
boolean RF22Datagram::recvfrom(uint8_t* buf, uint8_t* len, uint8_t* from, uint8_t* to, uint8_t* id, uint8_t* flags) { if (from) *from = headerFrom(); if (to) *to = headerTo(); if (id) *id = headerId(); if (flags) *flags = headerFlags(); return recv(buf, len); }
bool RHDatagram::recvfrom(uint8_t* buf, uint8_t* len, uint8_t* from, uint8_t* to, uint8_t* id, uint8_t* flags) { if (_driver.recv(buf, len)) { if (from) *from = headerFrom(); if (to) *to = headerTo(); if (id) *id = headerId(); if (flags) *flags = headerFlags(); return true; } return false; }