Comments on: RS232 Communication – The Level Conversion

By: Kansai

Kansai — Mon, 16 Jan 2012 06:35:37 +0000

Hello. Great Tutorial
Thanks for the effort.
I just have a (very) basic question
I built the circuit as you showed, and i am now connecting it to a PC. I want to perform the autotest (pins 13 and 14 connected) to see if it is working, so I run the hyperterminal.
at this point, what is what I should see in the hyperterminal to know it is working or not. COuld you specify please?. I ve tried both cases (pin 13 and 14 connected and disconnected) and the behavior is the same. I just type stuff and it appears in the screen.

By: brian

brian — Wed, 06 Jul 2011 21:09:11 +0000

Hello Avinash,i have a digitizer board (Lectra systeme) manufactured by lockheeds and calcomp,it is designed to plot co-ordinates for clothing design patterns, with the aid of pc software. Unfortunetly i dont have any cables and not quite sure what cable specification should be, after endless searching and buying various cables and adapters i am no further with getting it up and running. If i send more information and photos from the ports can you advise me? thanks brian

By: Tuhin

Tuhin — Tue, 14 Jun 2011 16:51:14 +0000

Hi Avinash, I want to write a c code (instead of using a 3rd pirty software) for serial(rs232) comunication with atmega32. I am using a laptop and it dosen’t have a serial port so I have bought USB to RS232 converter from your website. Can you provide me c code example to do so.

Thank you in advance.

By: avr noob

avr noob — Sun, 05 Jun 2011 08:15:57 +0000

Why??

Had i said something wrong?
Controller Area Network (CAN)

Please sir..i would be highly obliged…

By: Avinash

Avinash — Sun, 05 Jun 2011 03:39:47 +0000

@avr noob

NOT at all !

By: avr noob

avr noob — Sat, 04 Jun 2011 20:07:06 +0000

Can you please mail me the CAN bus tutorial.

By: RS232 Communication – The Basics | eXtreme Electronics

RS232 Communication – The Basics | eXtreme Electronics — Thu, 02 Jun 2011 04:48:39 +0000

[...] RS232 Level Convertor [...]

By: Avinash

Avinash — Sat, 21 May 2011 01:05:41 +0000

@Alex you miss the basic. USB to Serial converters are designed to connect legacy serial peripheral to USB port. Since all serial device works on RS232 levels the commercial USB to Serial convertor (with DB9 connector) also converts USB TTL signal to RS232 using a chip similar to max232 so that legacy devices could accept the signal.

So the POINT is that if you use a USB to Serial Conveter (commercial make with a DB9 connecter) you must use max232 as level convertor.

By: Alex

Alex — Fri, 20 May 2011 21:10:32 +0000

Hi, great tutorial!

I just have a question… If I use a USB to RS232 converter, do I really need to use a level converter (MAX232) ? As usb is already designed to use just 5v.. right?

So I wonder if I can connect my pic directly to my usb to rs232 converter.

Thanks in advance!

By: samuel

samuel — Thu, 05 May 2011 22:47:28 +0000

ya tengo el circuito anterior pero al tecleear en la hiperterminal no me deja a q se debe el circuito ya lo hice como 5 veces y no acabo de entender por que puede ser???

By: Amir

Amir — Sat, 26 Feb 2011 11:18:15 +0000

It was fantastic. Especially the test method
Thank you very much

By: Ali

Ali — Mon, 23 Aug 2010 17:02:26 +0000

Thankyou Avinash!

By: Tomas

Tomas — Thu, 05 Aug 2010 14:25:33 +0000

Excellent tutorial! Thanks for the infos!

By: sekkai

sekkai — Tue, 27 Jul 2010 16:52:43 +0000

thank you all, you were very helpful

By: Avinash

Avinash — Fri, 23 Jul 2010 10:26:15 +0000

@Joaquin

Although not rated but MAX232 works good in low (3.3v) too!

Just use Vcc as 3.6v same as your ATxmega32Ad

By: Joaquin

Joaquin — Fri, 23 Jul 2010 09:14:29 +0000

I am planning to use an UART to RS232 converter, can I use this circuit for that? An by the way, the microcontroller that I will be using is an ATxmega32Ad which has maximum operating voltage at 3.6V, can I still use this circuit?

By: sekkai

sekkai — Wed, 21 Jul 2010 12:45:40 +0000

Dear,

thanks for this great tutorial..

i just wanted to know if i can use the if i can use the internal calibrated rc oscillator instead of external crystal

and what connections i must use for the attiny2313 when testing it

i supose i must connect the two data wires(RXD & TXD), the GND and VCC

By: Avinash

Avinash — Fri, 09 Jul 2010 07:04:51 +0000

@Ashish
For USB To Serial Conversion See this
http://www.dharmanitech.com/search/label/USB%20converter

By: ashish

ashish — Wed, 07 Jul 2010 17:08:49 +0000

hey, thank you for your tutorials, can u also tell how we can make usb to serial port conversion

By: Rohit

Rohit — Mon, 14 Jun 2010 06:19:27 +0000

@Avinash – if the converter is not faulty then why is it not receiving anything? I am using a software called RS232 analyzer to check it – here it shows all signals working except Rx (receive).

In fact I have connected the converter to an external serial device (OBD scanner) – this device can receive signals from the converter (activity LEDs on the scanner flash on receiving valid command) but whatever data the scanner outputs is simply not received. This is consisten with the loopback test (using the above software as well as hyperterminal) – Txed characters are simply not Rxed back.