enhancement

[GoogleCodeExporter]

What steps will reproduce the problem?

I tried to send information without stopping , (I need to send data each 
milliseconds or less),then I tested with this loop.
for (;;) 
  {
        xbee_conTx(xbee, con,"1");
  }

If log enabled,this is, xbee_logSetLevel(1) or more, I can send data but 
receive this error:
 [io.c:218] xbee_io_writeRawByte() 0x8aac008: Error detected (Resource temporarily unavailable)
When log is disabled, can't send data properly.

To fix that i set, #define XBEE_IO_RETRIES_WARN 0 
Now, with or without log i can send data  properly and receiving this at 
3000byts/second 

But the main problem is that while the program is running, memory is allocated, 
then comes a time when the computer crashes.I do not know how to release memory.

I'm using Xbee Series2,Ubuntu 11.10,tested most of baud rates, now 57600.

Original issue reported on code.google.com by Samuz...@gmail.com on 10 Jan 2012 at 2:57

[GoogleCodeExporter]

Hi Victor

The steps you outline will indeed fill up the computer's memory.

Calling xbee_conTx() will simply queue the packet to be sent and return.
If you want it to wait until confirmation that the packet has been set before 
returning, then please enable the 'waitForAck' option for the connection.

Use the code snippet below:

struct xbee_conOptions opts;
/* enable waitForAck... this allows us to see if the packet was sent 
successfully! */
xbee_conOptions(xbee, con, &opts, NULL);
opts.waitForAck = 1;
xbee_conOptions(xbee, con, NULL, &opts);

Please implement this and report back.

Original comment by attie@attie.co.uk on 10 Jan 2012 at 8:25

[GoogleCodeExporter]

Ok, now the memory is not affected.
however, i'm receiving data about 800 bytes/seconds. Xbee manual says 240kbps 
wifi and 115200 serial maximum.
but, working perfectly!
the checksum are implement?
if there are problems sending, I get the error log automatically?
Thanks!

Original comment by Samuz...@gmail.com on 10 Jan 2012 at 11:09

[GoogleCodeExporter]

Glad to hear that it sorted the memory,

You will see a lower transfer rate. This is because the message is now being 
sent, and then libxbee is waiting for a response from the remote node before 
continuing. If no response is received then the transmission will timeout, and 
xbee_conTx() returns an error (this can take a short while).

The data rates you mention are the raw interface rates.

The ~240kbps refers to kilo-bits per second (30kBps - kilo-BYTES per second). 
This is the limiting factor in the communications. It is also worth noting that 
it isn't 'WiFi', but another protocol. If you consider the overhead for this 
protocol (say the size of the payload) then you can expect a maximum rate of 
about 15kBps. In reality this is still a generous estimate - you measured 3kBps.

The checksum is implemented, yes. If there is a problem sending then your call 
to xbee_conTx() will return an error (because you enabled waitForAck).

The maximum of 115200 baud, is again kilo-bits per second. This is just the 
speed at which you can communicate with the processor on the XBee module.
This is noted in the Series 1 XBee manual to be unstable, and is actually 
111,111 baud. This is why I tend to use 57600.

It is also possible that before you were suffering from data loss, which would 
have gone un-noticed because you were sending the same single byte payload each 
time. Retry your test with a rolling byte, and then ensure that the data at the 
other end is correct.

You may have unearthed an issue with my implementation of hardware flow 
control, so I will investigate this.

Original comment by attie@attie.co.uk on 11 Jan 2012 at 8:08

• Changed state: Accepted

[GoogleCodeExporter]

Please retry your original program (without waitForAck enabled) with the latest 
commit (f40f89087b4c).

Your program will still over-consume memory and crash, but the 'errors' should 
have disappeared.

Original comment by attie@attie.co.uk on 11 Jan 2012 at 8:16

• Changed state: Started

[GoogleCodeExporter]

Yes, errors disappear.
When i said "wifi" was trying to say "over the air", In Brazil it can mean wifi.
I have not forgotten conversion, is what I expected something around 10kBps.
But now, seems working good!

Original comment by Samuz...@gmail.com on 11 Jan 2012 at 5:15

[GoogleCodeExporter]

Great! Thanks for confirming that.

I just wanted to keep things straight :) In the UK WiFi is used all the time 
for 802.11 wireless networking.

Original comment by attie@attie.co.uk on 11 Jan 2012 at 11:21

• Changed state: Fixed