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Topic: Wiport serial to wifi interfacing problem (Read 875 times) previous topic - next topic

hamlet

Nov 12, 2008, 03:20 pm Last Edit: Nov 12, 2008, 03:21 pm by hamlet Reason: 1
Hi,

I'm trying to hook up Arduino with a serial<->wifi port, the Lantronix Wiport (www.lantronix.com/device-networking/embedded-device-servers/wiport.html) , my original thought was to use the TWI on arduino (The TX/RX pin, or Pin 0 & 1) to interface with the serial port on the Wiport. According to the spec the Wiport supports a 3.3v CMOS level serial.
So here's the problem, there's a TXD and RXD pins on the board, and it tolerates up to 5V. So I just give it a try and connect the TX pin from Arduino to the RXD pin of the Wiport, and the same for the RX pin. I'm sure the baud rate is right, but nothing happens, any idea? Would a simple level shifter do the job? Or I'm just mismatching the concepts for all these RS232/CMOS/5/3.3V/TWI/TTL?

Thanks!

Cheers,
Hamlet

Grumpy_Mike

Check that TX and RX actually mean what you think they mean. You need to connect an input to an output and depending on if the equipment is defined as data terminal equipment (DTE) or  data communicating equipment (DCE) the TX might be an input or an output. Look up RS232 on Wikipedia.

http://en.wikipedia.org/wiki/RS232

hamlet

Hi friends,

It's working now, well..half of it.
I forgot to common ground them.

Now the data from Arduino is flooding from the UDP port (using the nice UDP library + processing). But when I send messages through the UDP port, Arduino doesn't response. I guess it is because the 3.3V output from Wiport is n't a good feed for Arduino.

Any suggestion for a simple pull up ic/chip? Or any thread about this?

Cheers,
Hamlet

A picture of the wires
http://farm4.static.flickr.com/3175/3024577055_3a287ed7b8.jpg?v=0

Tuckie

you could always just use something like this: http://www.futurlec.com/Mini_Logic.shtml

hamlet

Is it possible to just use a transistor and utilize the 5V supply from arduino to do the conversion?



chrisrobin28

Data Sheet for 74LVC126A is here:

http://www.datasheetcatalog.org/datasheets/134/375818_DS.pdf

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