Olimex Support Forum

ARM => ST => Topic started by: emanuelcsm on November 17, 2014, 06:26:22 pm

Title: STM32-E407 Ethernet Speed
Post by: emanuelcsm on November 17, 2014, 06:26:22 pm
Hello,

I purchased a STM32-E407 that did not arrivied yet, but I'm already writing some codes.
I now that Ethernet speed is 100Mbps, but I'd like to know how fast can I send data to a telnet terminal? In another words, what is the real data rate of ethernet port?

Thanks in advance.
Title: Re: STM32-E407 Ethernet Speed
Post by: JohnS on November 18, 2014, 06:43:24 pm
telnet is by design quite slow.  Try it and see.

John
Title: Re: STM32-E407 Ethernet Speed
Post by: MBR on November 19, 2014, 11:49:33 pm
Yes, the telnel is slow, because is designed for interactivity (low latency), so it sends lots of small packets with a big overhead. If you want to try with some kind of standard protocols, try FTP or HTTP download of big files (e.g. ISO images). Or use netcat, with /dev/zero as the input on the source side and /dev/null as the output on the destination side.
Title: Re: STM32-E407 Ethernet Speed
Post by: emanuelcsm on November 20, 2014, 02:43:10 am
Thanks JohnS and MBR.

I have never transfered data through Ethernet. Only UART using USB/Serial Converters.

What I need to do is read an ADC data and show a graph in a computer (windows unfortunatly), just like an ociloscope.

Can I do it using HTTP on ChibOS? Does any one know where do I find an examples for noob.

PS.: I'm good programmer, not a 100% noob, just don't know anything about Ethernet protocol in embedded aplications.

Thanks in advance
Title: Re: STM32-E407 Ethernet Speed
Post by: JohnS on November 20, 2014, 10:28:22 am
I don't know about the small details of that OS but Ethernet is faster than UARTs etc.  telnet is pretty slow because that's how it is meant to be (yes the small packets etc, it's for a human watching chars echo on screen).

For fast use UDP else use TCP packets.  Easy to do, tons of source on the net.

HTTP if you want, but it's another layer and adds what?  Probably nothing you want.

Er... did you know there's a logic analyser using STM32F4 (with SUMP)?  It's here http://jjmz.free.fr/?p=148
Might give some ideas.

John
Title: Re: STM32-E407 Ethernet Speed
Post by: emanuelcsm on November 24, 2014, 07:21:46 pm
Thanks JohnS

It helped a lot, now I have a solid point to start.

Thanks