Comments on: Using the USART of AVR Microcontrollers : Reading and Writing Data

By: Suheb Naik

Suheb Naik — Fri, 03 Feb 2012 07:25:53 +0000

Hello sir,
i am very grateful for valuable information you have shared with us. However Our project is about encryption n decryption. and we are trying for PC-PC communication. First we will encrypt the msg & through the RF link pass it to another PC. There we will decrypt & then display. its wireless communication. Coding we are trying 2 do through Twofish algorithm. & the software for coding we are suppose 2 use is MATLAB. can you please guide us about coding part?

By: manfred

manfred — Wed, 01 Feb 2012 21:11:59 +0000

Thank you soooo much.Very Helpful.Very Good. Greetings Manfred

By: abhishek

abhishek — Sun, 25 Dec 2011 07:14:56 +0000

Hello Sir,
I am totally thankful for ur tutorials ,but i have a question,I have got ur CP2102 Based Module,which has successfully worked on Windows ,I have project to be implemented in Linux so would u please hint me about its use in Linux.Atlest some refrences,thanks .

By: Avinash

Avinash — Wed, 05 Oct 2011 03:46:13 +0000

@Shahgufta,

To send 32 bit int using USART, use following snippet.

uint32_t value=11998652; //32 bit unsigned int value

USARTWriteChar(value);
USARTWriteChar(value>>8);
USARTWriteChar(value>>16);
USARTWriteChar(value>>24);

on receiving side. Write

uint32_t USARTReadUINT32();
{
uint8_t b1,b2,b3,b4;

b1=USARTReadChar();
b2=USARTReadChar();
b3=USARTReadChar();
b4=USARTReadChar();

return ((b4< <24)|(b3<<16)|(b2<<8)|(b1));
}

for furthur discussion please use the forum.
http://forum.extremeelectronics.co.in/

By: Shahgufta

Shahgufta — Tue, 04 Oct 2011 15:19:44 +0000

Hai…
Great work sir. Iam doing a project to send 32 bit data from atmega32 to pc using RS232 serial communication. I know to transfer 8 bit data but I dont know how to transfer 32 bit data. Please help me.

Regards,
Shahgufta

By: jk bawa

jk bawa — Thu, 25 Aug 2011 09:26:25 +0000

hi, avinash.
we are planing to make pressure horn melody, in the market many people make it, can you let us know how can we load songs in processor, that trigers the 6 relays and relays switch on the air pressure controllers.
pls mail me the details

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By: interfacing PC(MATLAB) with AT89C51

interfacing PC(MATLAB) with AT89C51 — Sat, 28 May 2011 05:51:43 +0000

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By: Nikunj

Nikunj — Thu, 19 May 2011 05:55:49 +0000

Hi,
Can You tell me how to use the output given by USART into another program like in a c++ or c# program?

By: Jithu Sunny

Jithu Sunny — Sat, 30 Apr 2011 11:14:44 +0000

Fixed it. Sent data by prefixing a symbol(.). Sorry that I dint read your RF comm tut completely. Another query is regarding multithreading on Atmega8. How can it be done? Any pointers?

Thanks

By: Jithu Sunny

Jithu Sunny — Sun, 17 Apr 2011 17:45:37 +0000

Hi Avinash,
Thanks once again for this simply wonderful tutorial series(I’m afraid you’ll get bored by seeing appreciation being crowded in your site..!)

I request you to please see the following & give me some pointers on how to proceed,

I have successfully loop-back tested your code using a CP2102 & an Atmega8.

Then I added a 433 Mhz TX & RX pair in between this loop back(Of course another MCU to take output from). Now the problem is that in addition to the intended data, I’m getting continuous junk values interspersed with it.

What is to be done to solve this?
Interrupts? Else how?

By: kholis

kholis — Mon, 11 Apr 2011 13:51:31 +0000

Dear Avinash,

this is awesome.. I’ve tried using serial Attiny2313 with ACM(Abstract Communication Mode).
It works in Windows and Ubuntu. But it doesn’t work in Linux Angstrom. I use Beagleboard with Linux Angstrom in it. So that, I can’t use that communication in Beagleboard.
Is this serial CP2102 module using ACM?

Thanks for your kindness

By: Avinash

Avinash — Fri, 08 Apr 2011 10:32:34 +0000

@Sandeep

Which Side the USB Side or the UART Side?

I don’t like technical people ask question which requires me to as a question in return!

You had a risk of me deleting the comment straight away.

By: Sandeep

Sandeep — Fri, 08 Apr 2011 10:19:10 +0000

Dear Avinash,
Thanks for nice tutorial. I want to know the maximum length of cable that can be supported for data transfer if we use CP2102 module.

By: vishwanath

vishwanath — Tue, 25 Jan 2011 19:01:01 +0000

sir,
your tutorials have once again proved invaluable to me.however i have a small problem.if i need to control a motor using arrow keys from serial port,i ant do so,because,arrow keys dont have ascii values.please,i request you to help me out.

By: jose albuja

jose albuja — Mon, 17 Jan 2011 19:15:17 +0000

hola les hago una pregunta quiero enviar comandos AT a un atmega32 por comunicación serial..!!! como los puedo enviar tengo algo asi pero no me esta funcionando:
printf(“AT+CMGF=1″);
putchar(13);

By: Avinash

Avinash — Fri, 14 Jan 2011 04:54:01 +0000

@SJ

The USB to Serial Adaptors (Virtual Com Ports) has a TTL to RS232 convertor in them. Which makes their i/o RS232 from the TTL voltage of USB. So again you need one for RS232 to TTL Convertor as you require on a real com port.

By: SJ

SJ — Sat, 08 Jan 2011 10:55:36 +0000

Hi, thanks for your write up.

In your explanation you mention that the virtual com port also require RS232 to TTL converter. If the virtual com port is USB based converter isn’t necessary as the maximum voltage of USB protocol is +5V.

By: kaba

kaba — Fri, 07 Jan 2011 16:01:34 +0000

AVR and USART
Project with ATMEGA8 and PC software.
In the project is convert character to integer or single…
http://openthermmonitor.ic.cz/