PCB design

Questions relating to designing PCBs

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AJITnayak
Posts: 60
Joined: Mon Feb 25, 2013 6:22 am
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PCB design

Post by AJITnayak » Tue Mar 12, 2013 4:54 am

Dear all.

Please let me know where i can get schematic for below requirement.

i wanna create simple schematic where i can take a TTL input and convert in he form RS232/RS485 (both)

example. I wanna read data from arduino board. and interface with RS485 and RS232 communication modules.
i know we can use serial monitor to view data they are in TTL format.SO i wanna create ttl to rs232 , rs232 to rs 485 or ttl to rs485 devices for interface with module so that it reside on main PCB.
But i need circuit where i can take data in TTL format and convert into both format.
INPUT:ttl format
output1:RS232
output2:RS485
Best Regards
Ajit Nayak

Mr.Paul
Posts: 6
Joined: Tue Mar 12, 2013 5:18 pm

Re: PCB design

Post by Mr.Paul » Tue Mar 12, 2013 5:21 pm

http://www.ti.com/lit/ds/symlink/max232.pdf

Should do the trick very nicely. The spec sheet will give you lots of guidance on a circuit.

AJITnayak
Posts: 60
Joined: Mon Feb 25, 2013 6:22 am
Location: DELHI
Contact:

Re: PCB design

Post by AJITnayak » Tue Mar 12, 2013 9:50 pm

If you can post simple circuit diagram , it better me to under stand

Suppose assume i have Arduino board. I wanna read data from serial port which are @ ttl level.
how i should give ttl input max 232 and how output are taken.
is it possible to do full duplex using max 232 .
Best Regards
Ajit Nayak

Mr.Paul
Posts: 6
Joined: Tue Mar 12, 2013 5:18 pm

Re: PCB design

Post by Mr.Paul » Wed Mar 13, 2013 7:34 am

From where you, design wise, I suspect you might be better off with a premade product. If you google RS232 Arduino Shield you will find some shields all made and ready to go. Googling MAX232 Arduino (or RS232 Arduino) will find you some nice hits like http://www.endurance-robotics.com/product.aspx?id=190 for some guidance if you really want to do it yourself.

It is a very straightforward chip to use.

AJITnayak
Posts: 60
Joined: Mon Feb 25, 2013 6:22 am
Location: DELHI
Contact:

Re: PCB design

Post by AJITnayak » Wed Mar 13, 2013 9:31 pm

Mr paul ,

Thanks for pdf data. please let me know how we can do it for ttl to rs485


Mr.Paul wrote:From where you, design wise, I suspect you might be better off with a premade product. If you google RS232 Arduino Shield you will find some shields all made and ready to go. Googling MAX232 Arduino (or RS232 Arduino) will find you some nice hits like http://www.endurance-robotics.com/product.aspx?id=190 for some guidance if you really want to do it yourself.

It is a very straightforward chip to use.
Best Regards
Ajit Nayak

Mr.Paul
Posts: 6
Joined: Tue Mar 12, 2013 5:18 pm

Re: PCB design

Post by Mr.Paul » Sat Mar 16, 2013 4:03 pm

485 Definitely gets tricky, but google can help. For example

http://www.linear.com/product/LTC1334

Looks like it can do both 232 and 485, and can do the voltage conversions as well. The datasheet, linked on that page, has some sample applications. "rs-485 driver chip" has more hits, but I don't have any experience with any of them, so hey, you're on you're own :)

macegr
Posts: 380
Joined: Wed Feb 27, 2008 4:44 pm

Re: PCB design

Post by macegr » Sat Mar 16, 2013 4:41 pm

SN75176 is much simpler for half-duplex (three wire) RS485. Nothing too scary about it.

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