ESP8266 Community Forum

- Fri Dec 12, 2014 11:53 am #4682 So if I have this right; if both devices consider themselves a DCE (Communication Device) then they require the RX and TX to be crossed. If one device is DCE and the other DTE (Terminal Equipment) then a straight-through TX-TX, RX-RX is required for communication.

As both my Arduino and CP2102 USB to UART TTL required "hooking up" in the DCE - DTE formation does this made the Arduino and TTL DCE and the ESP DTE? or do I have it back-to-front?

vilTech, as requested, I have attached an images for my CP2102 USB to UART TTL pin out.

You do not have the required permissions to view the files attached to this post.

Kind Regards,
Harold Clements

ICQ: 621094716

- Fri Dec 12, 2014 1:08 pm #4690

So if I have this right; if both devices consider themselves a DCE (Communication Device) then they require the RX and TX to be crossed. If one device is DCE and the other DTE (Terminal Equipment) then a straight-through TX-TX, RX-RX is required for communication.

Aha, instead of a solution you want to understand the WHAT and HOW, that's admirable

Your theory is IN PRINCIPLE correct, that's the way it should be handled by DTE/DCE equipment providers. Some suppliers still think they are more clever than THE PRINCIPLE, and think they are doing the customer a favor by "crossing" the labeling of TX/RX.

I personally gave up on believing TX/RX labels long time ago, connect the TX/RX lines the way I THINK it should be. If it doesn't work, cross!! Might not now sound very professional, but my solution NEVER fails in the end, trying to understand equipment suppliers DOES.

Good luck and have fun!

- Fri Dec 12, 2014 4:12 pm #4708

So if I have this right; if both devices consider themselves a DCE (Communication Device) then they require the RX and TX to be crossed. If one device is DCE and the other DTE (Terminal Equipment) then a straight-through TX-TX, RX-RX is required for communication.

Aha, instead of a solution you want to understand the WHAT and HOW, that's admirable

Your theory is IN PRINCIPLE correct, that's the way it should be handled by DTE/DCE equipment providers. Some suppliers still think they are more clever than THE PRINCIPLE, and think they are doing the customer a favor by "crossing" the labeling of TX/RX.

I personally gave up on believing TX/RX labels long time ago, connect the TX/RX lines the way I THINK it should be. If it doesn't work, cross!! Might not now sound very professional, but my solution NEVER fails in the end, trying to understand equipment suppliers DOES.

Good luck and have fun!

So true.. I caried a rs232 led box and a shitload of db9/db25 converters for years to find out what is txd or rxd.

Now we got usb ..

- Sat Dec 13, 2014 10:44 am #4749

So true.. I caried a rs232 led box and a shitload of db9/db25 converters for years to find out what is txd or rxd.

Now we got usb ..

Those we're the days Sjaak..... I remember often using 2 db9/db25 converters, some sex-changers, 1 rs232 led box and a selfbuilt db25 cross adapter with shorted handshake lines to get 1 rs232 connection going.

Hardware beats any theory