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Topic: RS485 and some Arduinos (Read 3673 times) previous topic - next topic

Cristal

Hello all,

I nedd a good tutorial to connect some Arduinos with RS485, in my interface I am using the max485.

thank you for the help,


Cristal

Thank you very much Igor, that solved my problem.

(PS No problem I speak spanish)

Regards,

pwillard

#3
Jun 22, 2009, 10:34 pm Last Edit: Jun 22, 2009, 10:36 pm by pwillard Reason: 1
I just started working on an RS485 design myself, using newsoftserial9.

I just built an RS232-RS485 adapter for the PC.  I'm looking to string a number of devices together using the multi-drop capabilities of RS485.

I don't speak Spanish... so if you end up doing things you can share... that would be great.

Cristal

pwillard

maybe this can help you

http://gdallaire.net/blog/?p=39

regards,

pwillard

Thanks... but he was being real sketchy about how he got it working...  and for some reason his routines would cause my arduino to reset when used with newsoftserial9.  I didn't have the desire to debug the reason why... so I started over.   (He was an inspiration though).

Igor's stuff is much more interesting.

Igor R

Hi,

If I have some free time, I´ll traduce it.


Regards,



Igor R.

Cristal

"...Igor's stuff is much more interesting."

I agree with you Pwillard and Igor is very, very helpfull.  

I am discussing some ideas with him in the international forum.

Regards,

Igor R

#8
Jun 24, 2009, 08:57 pm Last Edit: Jun 24, 2009, 09:04 pm by igorreal Reason: 1
Hi,

I´ve just finish one example. There are 3 Arduinos, one master and two slaves.
The slaves have a led in their pin 13.
The control of switch on/off is with 2 buttons from Master.

Here you can see a photo:






And the video working:

[media]http://www.youtube.com/watch?v=S9FSQaToVZ4[/media]




A diagram of the protocol:



It´s based on a proffesional machine: http://www.cdautomation.com/download/ENG_L_M_FUJI_RS485_COMM_for_FRENIC-Mini.PDF




It´s important the lenght of the conecttion from transceiver (MAX485 or 75176) to the bus be as short as possible. I always do my connections like the photo (black and white are the bus).








Now, It´s easy do my own functions to control an arduino network. I´ve prefered use something based on a professional machine, because for sure my applications will be easiers.

To see the data in the bus,you can use RealTerm http://realterm.sourceforge.net/. It´s free and you can see hex and ascii data.

You can see the code of this example ==> http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1245014666/15#15



Regards,



Igor R.

Daniel

#9
Jul 02, 2009, 02:32 pm Last Edit: Jul 02, 2009, 02:36 pm by danneman Reason: 1
Igor: Nice Work!

Do you have a schematic view of your 485 converter? I can recognize the max485 and a resistor but what is it on the top right corner? is it a voltageregulator?

Thanks
//Daniel

Igor R

It´s just a jumper to add/remove the resistor...

Regards,


Igor R.

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