Arduino UNO R3, MEGA2560 and RS485

Hi, I'm trying to make a project concerning with transfering data between UNO R3 & MEGA2560 via RS485. I've tried all ways that have been posted on the Internet but they can't work correctly. Anyone can help me, please? Furthermore, can i transfer text in this case? Thanks for reading my topic!

I've tried all ways that have been posted on the Internet

Have you? All of them?

The thing is you are doing something wrong because all those methods on the Internet are not wrong. Number 42 and number 1739 methods definitely work.

Number 42 and number 1739 methods, what are they? Can you give me more specific information? Thanks :)

Are you trying to do full duplex or half duplex communication?

nhhoang2812: Can you give me more specific information?

Only if you give me more specific information.

Hint turn your irony filter off.

mikb55: Are you trying to do full duplex or half duplex communication?

Full duplex More detailedly, Master (MEGA560) receives signals from mobile phone via Bluetooth, then it transer them to Slave (UNO R3). Slave, after that, controls 2 motors and takes motor's speed from speed sensor and send it back to Master. Then, Master receives and display it on LCD. That's an overview of my project. I'm now still stuck with RS485...

Grumpy_Mike: Only if you give me more specific information.

Hint turn your irony filter off.

More detailedly, Master (MEGA560) receives signals from mobile phone via module Bluetooth HC-06, then it transer them to Slave (UNO R3). Slave, after that, controls 2 motors and takes motor's speed from speed sensor IR FC-03 and send it back to Master. Then, Master receives and display it on LCD 1602A. That's an overview of my project. I'm now still stuck with RS485 (I use module TTL To RS485). Can you help me, please

Can you help me, please

Only if you ask the question correctly so that I can understand it. Please read this:- How to use this forum It will tell you how to ask a question, and tell you all the things you have to include to ask a question that stands a chance of being answered. The minimum is some code and a schematic with a clear photograph of how you have wired things up Only then does any one have the slightest chance of beginning to guess at what you have done wrong.

The question you asked was rubbish. It did not say what you had done. It just said that you had tried ALL the things on the internet, which is clearly a lie. You might have tried some of them but you never tried all of them.

The fact that you did not understand how very poor your question was, even after the prompting with TWO replies makes me think that you are not going to understand any answer given to you and that I am wasting my time trying to talk to you.

Grumpy_Mike: Only if you ask the question correctly so that I can understand it. Please read this:- How to use this forum It will tell you how to ask a question, and tell you all the things you have to include to ask a question that stands a chance of being answered. The minimum is some code and a schematic with a clear photograph of how you have wired things up Only then does any one have the slightest chance of beginning to guess at what you have done wrong.

The question you asked was rubbish. It did not say what you had done. It just said that you had tried ALL the things on the internet, which is clearly a lie. You might have tried some of them but you never tried all of them.

The fact that you did not understand how very poor your question was, even after the prompting with TWO replies makes me think that you are not going to understand any answer given to you and that I am wasting my time trying to talk to you.

I got it. Thanks for your advice!

nhhoang2812: More detailedly, Master (MEGA560) receives signals from mobile phone via module Bluetooth HC-06, then it transer them to Slave (UNO R3). Slave, after that, controls 2 motors and takes motor's speed from speed sensor IR FC-03 and send it back to Master. Then, Master receives and display it on LCD 1602A. That's an overview of my project. I'm now still stuck with RS485 (I use module TTL To RS485).

Draw a wiring diagram showing the connections between all the pins. In particular show how the DE and RE pins are wired.

Is this how you connect from MEGA to UNO

|500x259

https://arduino-info.wikispaces.com/SoftwareSerialRS485Example