UART-how can i communicate

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Anonymous
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Hello All

   

As i am working with UART and there is requirement that RX of one device be connected to Tx of other and TX to RX.

   

So , if many devices are to be connected i can only have one  Master talking to all the slaves , but slaves cannot talk among themeselves and can only talk via master.

   

Is it right......

   

I can never have ring , bus or any other topology of communication

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9 Replies
Anonymous
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Hi,

   

     In UART protocol (more precisely RS232), RX of one device (say DTE) is connected to Tx of other device (say DCE). It is one-to-one communication i.e. you can connect UART between only 2 devices. For connecting multiple devices outside the board I would suggest to use USB. If you want to have the connection on the board then I suggest to use I2C for communicating with multiple devices.

   

 

   

You can get more details in some of the websites mentioned below.

   

https://sites.google.com/site/worldinfosharing/Home/technical/uart (It is my site and your comments would be welcomed to improve it)

   

http://en.wikipedia.org/wiki/Universal_asynchronous_receiver/transmitter

   

 

   

Regards,

   

Aniruddha

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Anonymous
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So, UART communication is only good for two devices and is no good for communication beteween multiple devices...

   

I think this is the major disadvantage when compared to any other serial communication protocols like CAN,USB, SPI etc...

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Anonymous
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Yes, but UART is one of the simplest communication. It is much simpler than CAN, USB. Now a days, UART is usually used for debugging purposes.

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Anonymous
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You should use the UART to drive a RS485 driver, which is used for multi drop application. GOOGLE is your friend.

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Anonymous
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Here is a application notes from TI. Hope it helps

   

 

   

http://www.ti.com/lit/an/slla112a/slla112a.pdf

   

 

   

🙂

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Bob_Marlowe
Level 10
Level 10
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UART is a rather old communication, to be more exact a UART was a piece of hardware-chip with some of the properties like the usermodule in the PSoC world. With those UARTs you built an interface. There were standards as TTY (current loop) or RS232, together with some more connector definitions (24-pin, 9 pin) and so on. Traditionally this was a point-to-point connection and not a bus. The UART interfaces on the development kits from Cypress are made for building RS232-connections which are a point-to-point connection as well. Afak only the 485-interface was designed for supporting a bus structure.

   

The principle of master-slave connections usually forbids slaves talking to each other to reduce bus arbitration. When you like to write programs for bus structures you ought to use bus-hardware as I2C, CAN or something similar because these are standards too.

   

The only networking protocoll Cypress offers is built for RF and is the "Star Network Protocol" and is available for PSoC1.

   

Todays commonly used Interfaces you'll find under the communication tab in Cypress's usermodules. Give google a chance to find out where they are used, what they are good for and what are their downgrades.

   

 

   

Happy communications

   

Bob 

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Anonymous
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 I have filed a patent for connecting more than 1 TX to one RX (PSoC in this case). I will let you know after it gets published. You can contact me for rights. I am  filing 6 patents which uses PSoCs in implementation. It is from Capsense to starter over current protection algorithms.  I am an ex-Cypress employee. -PSP  🙂

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mattl_01
Employee
Employee
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Inquiries regarding patents and other third party IP should be directed to the Cypress Legal Department.  Please contact Ryan Seguine (rxi@cypress.com).

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alli_264371
Level 4
Level 4
25 replies posted 10 replies posted 10 questions asked

Thanks for the email, I received a patent on the method of manufacturing touch buttons in the metal panel and would like to offer it a cypress, but the letters that I sent to customer support were ignored ..
Next i send the details to Ryan, but no answer..

   

If anyone want register my patent in her local country for 50-50 with me please contact me

   

Here is the explanation of method http://www.elegatec.com/extracted_buttons.pdf


I cannot confirm email and add messages due to a bug on your site, the email section is not active
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