Added relay role, and tweaked base to work with it

This commit is contained in:
maniacbug 2011-05-12 21:47:16 -07:00
parent d8b2512e0c
commit 2e7ea67093
1 changed files with 124 additions and 8 deletions

View File

@ -67,6 +67,41 @@ const node_info topology[] =
};
const short num_nodes = sizeof(topology)/sizeof(node_info);
/**
* Find where to send a message to reach the target node
*
* Given the @p target_node, find the child or parent of
* the @p current_node which will relay messages for the target.
*
* This is needed in a multi-hop system where the @p current_node
* is not adjacent to the @p target_node in the topology
*/
uint8_t find_node( uint8_t current_node, uint8_t target_node )
{
uint8_t out_node = target_node;
bool found_target = false;
while ( ! found_target )
{
if ( topology[out_node].parent_node == current_node )
{
found_target = true;
}
else
{
out_node = topology[out_node].parent_node;
// If we've made it all the way back to the base without finding
// common lineage with the to_node, we will just send it to our parent
if ( out_node == 0 || out_node == -1 )
{
out_node = topology[current_node].parent_node;
found_target = true;
}
}
}
return out_node;
}
//
// Role management
//
@ -189,24 +224,30 @@ void setup(void)
// Open pipes to other nodes for communication
//
// First listening pipe is #1
uint8_t current_pipe = 1;
// Each leaf node has a talking pipe that it will ping into, and a listening
// pipe that it will listen for the pong. Relay nodes also do this.
if ( role == role_leaf || role == role_relay )
{
// Write on our talking pipe
radio.openWritingPipe(topology[node_address].talking_pipe);
}
// Relay nodes have a special function. They open their listening pipe on pipe
// #0. This will get over-written every time we open a writing pipe. So
// Remember to re-open the reading pipe whenever we start to listen again.
if ( role == role_relay )
{
// Listen on our listening pipe
radio.openReadingPipe(current_pipe++,topology[node_address].listening_pipe);
radio.openReadingPipe(0,topology[node_address].listening_pipe);
}
// The base and relay nodes listens on all their children node's talking pipes
// and sends the pong back on the child node's specific listening pipe.
if ( role == role_base || role == role_relay )
{
// First child listening pipe is #1
uint8_t current_pipe = 1;
// The topology table tells us who our children are
int i = num_nodes;
while (i--)
@ -234,7 +275,7 @@ void setup(void)
if ( role == role_invalid )
{
printf("\n\r*** NO NODE ADDRESS ASSIGNED *** Send 1 through 6 to assign an address\n\r");
printf("\n\r*** NO NODE ADDRESS ASSIGNED *** Send 0 through 5 to assign an address\n\r");
}
}
@ -313,11 +354,16 @@ void loop(void)
// Construct the return payload (pong)
payload_t pong(node_address,ping.from_node,ping.time);
// Find the correct pipe for writing. We can only talk on one of our
// direct children's listening pipes. If the to_node is further out,
// it will get relayed.
uint8_t out_node = find_node(node_address,pong.to_node);
// Open the correct pipe for writing
radio.openWritingPipe(topology[pong.to_node].listening_pipe);
radio.openWritingPipe(topology[out_node].listening_pipe);
// Retain the low 2 bytes to identify the pipe for the spew
uint16_t pipe_id = topology[pong.to_node].listening_pipe & 0xffff;
uint16_t pipe_id = topology[out_node].listening_pipe & 0xffff;
// Send the final one back.
radio.write( &pong, sizeof(payload_t) );
@ -328,6 +374,76 @@ void loop(void)
radio.startListening();
}
}
//
// Relay role. Forward packets to the appropriate destination
//
if ( role == role_relay )
{
// if there is data ready
uint8_t pipe_num;
if ( radio.available(&pipe_num) )
{
// Dump the payloads until we've gotten everything
payload_t payload;
boolean done = false;
while (!done)
{
// Fetch the payload, and see if this was the last one.
done = radio.read( &payload, sizeof(payload_t) );
// Is this for us?
if ( payload.to_node == node_address )
{
// Treat it as a PONG
payload_printf(" ...PONG",payload);
printf(" Round-trip delay: %lu\n\r",millis()-payload.time);
}
else
{
// Relay it
// Spew it
payload_printf("RELAY IN",payload);
printf(" on pipe %u. ",pipe_num);
// Which pipe should we use to get the message to the "to_node"?
// We need to find a node who is OUR CHILD that either IS the to_node
// or has the to_node as one of ITS children. Failing that, we'll just
// send it back to the parent to deal with.
uint8_t out_node = find_node(node_address,payload.to_node);
// First, stop listening so we can talk
radio.stopListening();
// If this node is our child, we talk on it's listening pipe.
uint64_t out_pipe;
if ( topology[out_node].parent_node == node_address )
out_pipe = topology[out_node].listening_pipe;
// Otherwise, it's our parent so we talk on OUR talking pipe
else
out_pipe = topology[node_address].talking_pipe;
// Open the correct pipe for writing.
radio.openWritingPipe(out_pipe);
// Send the payload back out
radio.write( &payload, sizeof(payload_t) );
// Debug spew
uint16_t pipe_id = out_pipe & 0xffff;
printf("OUT on pipe %04x.\n\r",pipe_id);
}
}
// Now, resume listening so we catch the next packets.
radio.openReadingPipe(0,topology[node_address].listening_pipe);
radio.startListening();
}
}
//
// Listen for serial input, which is how we set the address