using RFM22 library in framing mode (more than 64bytes packets)

Projects Programming
1

I'm trying to send more than 64 bytes over radio using the RFM22 modules. Now my transmitter looks great but for some reason the receivers fails after several successfully receptions.

I was test the transmitter printing all the data every time that the receivers get a valid frame.

I only want to concat this frame in another to get almost 400 bytes packet.

Now my code:

RF22ReliableDatagram rf22(MyNODEID,CHIP_SS,RFM22_INT);


uint8_t  buffer[500];
uint16_t buffer_index=0;
uint16_t tiempo_ultimo_rx=millis();

void loop(){
    uint8_t buf[RF22_MAX_MESSAGE_LEN+1];
    uint8_t len = sizeof(buf);
    uint8_t from;
    uint8_t to;
    uint8_t id;

    if (buffer_index >= 400){buffer_index=0;}
    
    if(millis() - tiempo_ultimo_rx >= 200) {buffer_index=0;}
    
    if (rf22.recvfromAckTimeout(buf, &len, 1000, &from, &to, &id)){ 
       for (int i=0; i<len; i++){
         buffer[buffer_index+i] = buf[i]; 
         //Serial.write(buf[i]);
         tiempo_ultimo_rx=millis();  
         }
       
    buffer_index = buffer_index +len;
    Serial.println(buffer_index,DEC);
    }
}

This code only concat all the frames into a local buffer, and after this I will proccess it.
500 bytes like buffer is too much for a ATmega 328?
It's realy strange because it work for several receptions and then fails and stay like this.
If I debug how many bytes I get into the buffer:

Right:
127 (1º first frame)
254 (2º first frame)
342 (3º first frame)

When it fails and stay like this:
127 (1º first frame) loads the firts 127 bytes
127 (2º first frame) do not load nothing
88 (3º first frame) loads the rest

I test others ways but the problem still there..

I-D-E-A-S?? :grin:

2

500 bytes like buffer is too much for a ATmega 328?

You have a 500 byte buffer, buffer, and another buffer, buf, that is RF22_MAX_MESSAGE_LEN+1 bytes long. Between them, yes, that may be too much.

What value does RF22_MAX_MESSAGE_LEN have?

    if (buffer_index >= 400){buffer_index=0;}

Doyouhavesomethingagainstspaces?

This allows you to copy up to 100 bytes into a buffer that already contains data.

       for (int i=0; i<len; i++){
         buffer[buffer_index+i] = buf[i];

Here you copy len bytes. Is len less than 100?

3

Hi Paul!
The packet size is the buffer value (500)
And the frame RF22_MAX_MESSAGE_LEN is a 128 byte size.

The data that I'm reading do not have blank spaces, what I see about the transmitter is that it needs more time to send the 3 frames.

I will test is in a mega 128, this have a lot of RAM so I can discard if the problem comes from it.
Other idea is process the data at the incoming frame but I think that some data field is partial from the actual frame to the next, I mean is divided in to different frames.

I will try the same but in a bigger uP or using only datagram and not reliabledatagram

Best Regards!
Frank