All,
What kind of performance (in general) should I expect roundtripping a small packet (<20 bytes) from a pc to my Uno via the W5100 using the stock Arduino ethernet library? Currently I'm only seeing 250-500 milli-second times which seems VERY slow. Are my expectations out of wack? What are y'all seeing?
My application is remote control of a tethered robot over cat5. With those kinds of response times, it's too laggy to be reasonable.
If others of you out there are seeing much better performance, please let me know your configuration and I'll start digging more into my setup. If I'm stuck with this lag, I'll probably just move to 485 and be done with it.... Who knows, it's probably Windows messing me up again. (grin)
Thanks in advance for everyone's help.
What is the ping time for your setup? For my arduino connected to my router he time is below.
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.
C:\Documents and Settings\zoomkat>ping 192.168.1.102
Pinging 192.168.1.102 with 32 bytes of data:
Reply from 192.168.1.102: bytes=32 time=6ms TTL=128
Reply from 192.168.1.102: bytes=32 time=2ms TTL=128
Reply from 192.168.1.102: bytes=32 time=3ms TTL=128
Reply from 192.168.1.102: bytes=32 time=2ms TTL=128
Ping statistics for 192.168.1.102:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 2ms, Maximum = 6ms, Average = 3ms
C:\Documents and Settings\zoomkat>
Yes, I'm getting good performance on ping as well. Basically, on the Windows side, the entire delay is waiting for a response on the wire. On the. arduino side, everything from the point I get the message off SPI to the response is also fast. Frankly, I just can't figure it. On the windows side, I'm waiting hundreds of milli seconds.
Is anyone else out there getting fast round trips? Anything special about that setup? Anyone else seen these slow speeds and found where exactly its slow?
Thanks all.
Mark