Sending single transmission to multiple nodes?

[blebson]

So what I ended up doing was splitting the voltage into two different bytes and then combining them after transmission. It's a bit hackey but it works just fine.

[TomWS]

So what I ended up doing was splitting the voltage into two different bytes and then combining them after transmission. It's a bit hackey but it works just fine.

Uh, how is your 'basestation' implemented?  Is the packet processed by the same type of AVR processor as your node or is it processed by a different type of processor?

Tom

[blebson]

Different processor, it's sending from a Moteino to an ESP8266.

[TomWS]

Different processor, it's sending from a Moteino to an ESP8266.

Ok, you didn't post your code so I can't comment on that, therefore I suggest you do some research on "data alignment within structures" for the various processors you're using.  I think you'll find the answer to your difficulties in that research.

Tom

[blebson]

Thanks for your help!

[syrinxtech]

Good catch Tom....definitely sounds like a packing primitive is going to be in order here.

[TomWS]

Good catch Tom....definitely sounds like a packing primitive is going to be in order here.

Maybe not.  The ESP8266 does not like to have its primitives unaligned.  Reordering maybe...
Actually, on second thought, I'm not 100% sure that the radio.DATA is guaranteed to be aligned on a word although it should be.  OP can research and educate us ;-)

Tom

[CrayBer]

That's easily possible: just send the packet to node address 255 and all nodes will receive. The problem with broadcasts is ACKs which would collide. The typical approach to deal with that weakness is to just send the data redundantly. So instead of one packet you send 3 and hope that at least one makes it to every destination.

joe

Not sure if I'm missing something, but I have set node address to 255 and sent packet 3 times with 40ms delay between, however none of my nodes are receiving anything.

Code Select Expand

#define NODEALL       255                 // ID to send to ALL nodes

Code Select Expand

if (radio.sendWithRetry(NODEALL, (const void*)(&theData), sizeof(theData)))
  {
    Serial.println("ok 1");
  }

Any help appreciated

[Felix]

Actually the BROADCAST_ADDRESS has changed to 0:

https://github.com/LowPowerLab/RFM69/blob/master/RFM69.h#L163

https://github.com/LowPowerLab/RFM69/blob/master/RFM69.cpp#L410