How to read ATmega128RFA1 via UART-USB connected to the PC using HTerm?

You should set the UBRR0 Register BEFORE you Enable RX and TX.

anyone wrote:
> I'm not profitient in c. But at least You should try
>
> char str[]= "Hello world\0";
This is not necessary because the quotation marks already define a 
0-Termitated string in C. The \0 is appended automatically. So
char str[] = "1234" is 5 bytes long 0x31,0x32,0x33,0x34,0x00.

ektor wrote:
> I have a ATmega128RFA1 via UART-USB connected to the PC
Do you have a USB=> RS232 (with RS232 voltage levels) or a USB => UART 
(TTL) converter. You can't connect the Atmega UART to the RS232 directly 
since it has different voltage levels. Then you need a Level Converter 
IC like MAX232 or Max3232. And of cause you should check the right 
connection of Tx(AVR)=>Rx(PC) and vice versa

Beside wiring issues, a common point for UART failures are fuse -, 
clock settings and the choice of F_CPU.

Also check if hardware flow control is disabled in the terminal program.

Debug Hint: Write a endless loop in a test programm that transmits 
permanent, e.g. letter "A" and then configure the terminal until you see 
the "A".

And you're sure that you connected Pin1 of the Converter to Pin 47 and 
Pin4 of the Converter to Pin 46 of the Atmega? And of cause the ground 
(Pin6) to your target board GND?

The link to the USB converter is broken.
What hardware do you use at all (e.g. which RFA1 PCB, a comercial one or 
a home-brew)?

I don't have the RFA1. But as USB => UART TTL Converter this one works 
great: http://www.ebay.de/itm/400414654693

If your USB TTL converter is based on a FTDI Chip, of cause you have to 
install the drivers first (from here 
http://www.dresden-elektronik.de/funktechnik/service/downloads/software/?L=0 
or http://www.ftdichip.com/Drivers/VCP.htm )
After you did that you plug in your USB UART Converter and a virtual 
COM-Port should appear in the device manager like here: 
http://www.ladyada.net/images/arduino/devicemanager.jpg
Behind the name you see the assigned COM-Port number (e.g. COM12).
In hterm you connect to this COM-Port with the baudrate and 
configuration you also set in your atmega such as 9600 8N1.
Thats it.

Until now you didn't answered my question
Timmo H. wrote:
> And you're sure that you connected Pin1 of the Converter to Pin 47 and
> Pin4 of the Converter to Pin 46 of the Atmega? And of cause the ground
> (Pin6) to your target board GND?
Are you sure you checked the right connection?!

ektor wrote:
> The C code that I enclose is correct?
Now your code has changed since you last post. To use "printf" you have 
to do a little bit more:
http://www.mikrocontroller.net/articles/AVR-GCC-Tutorial#Die_Nutzung_von_sprintf_und_printf

But you can use your sendestring function which seems to be correct.
And you really should set the UBRR0 BEFORE you enable the tx and rx as I 
said before.

Hello¡¡

Timmo H. wrote:
> Until now you didn't answered my question

Sorry, I thought that with the picture was ok, I think all is correctly 
connected because it already design by deRFbreakout Board for pluggable 
radio 
modules(http://www.dresden-elektronik.de/funktechnik/products/boards-and-kits/development-boards/derfbreakout-board/description/?L=1).
In this case Pin1 of the Converter to Pin 28 and
Pin4 of the Converter to Pin 26 of the deRFbreakout Board.GND is aswell 
good coneccted.
I enclose a picture of the conections and the deRFbreakout Board 
Datasheet. I have checked all and I think is ok. My conponents are 
conected like i show you in the picture 222.


> But you can use your sendestring function which seems to be correct.

So If have the deRFmega128 programmed whit the first C code with the 
sendestring what should I do for get read anything in Hterm? Should I 
write anything for get data, or just should I be able to read without 
write?
I have tried all.:C

Thank you!!

Thank you for help but unfortunately I can not read data from 
ATmega128RFA1.
Whith the code that now I enclose, should I able to see a Hello World 
just connecting with Hterm?

Help¡¡

If you remove the while(1) endless loop, the string will be displayed 
again and again.

If you are the originator of this thread 
Beitrag "Verknüpfung der Sensordatenabfrage(LTC2498) mit der Funkverbindung(ATmega128RFA1)", please avoid double 
postings, lets stay at one thread and solve the issues step by step.

Hello,

I am sorry!!
Now I can read the messege on my Hterm¡¡
Thank you very much!!