Gen 7 Board Freezes after Receiving a few Characters

Hello Guys,

Am building my reprap, and I am having a problem with my electronics.
My setup is: Gen 7 Board with Atmega644 (no P at the end), connected to serial port via MAX232...
The problem is that when I download the Teacup Firmware (using latest version from [github.com]) it starts and prints the "start" and "ok" but if I press a couple of line feeds in a serial console, it responds with ok for a few times then hangs, and stops doing anything until a reset is pressed or power cycled.
needless to say, I also tried the reprap host software and pronterface which starts but couldn't do useful communications with the board. I was able to check the temperature of the thermistor for a few times, and turn the heater on for one time.

When installing the test firmware, it ran fine and kept sending messages for 15 minutes until I resetted it.

** I am using Arduino release 0022 with the latest gen 7 hardware folder.

Did anyone have such a problem??

** Sorry, but I have just noticed I have posted in the wrong folder.. can it be moved to the mainstream firmware folder???

Edited 1 time(s). Last edit at 01/31/2012 03:44PM by FouadAtmeh.

Hmm. Well, using a host when a serial console doesn't work is a bit pointless, so no need to check that. Hosts don't do any magic, the just send snippets or entire files of text.

My best guess is, your connection is flaky on the hardware level. Poorly working USB, lots of electromagnetic noise into the board, not sufficiently shielded cable, missing GND on the MAX232 board or something like that.

You might want to try with a lower baud rate, like 19200 baud. This can be set in Teacup's config.h, search for "BAUD".

If you have a bit programming experience, you might be able to find where exactly Teacup hangs. Even a poor connection shouldn't lock up the firmware entirely. Serial code is in, well, serial.c

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Thanx for your reply, I have already tried several baud-rates between 2400 all the way up to 115200 !!!
Serial cable seems fine as I am able to transmit and receive through it when I make a loop, but I will give it another look.. I'll also try another pc with a serial port.

It seems I must roll up my sleeves and dive into programming (bit rusty there).. looking at the bright side, it would be a chance for me to learn C

If anybody else had faced anything like that, please share

If baud rate doesn't help then it may be a hardware issue. Try touching up solder joints on the relevant pins. That is, anything connected to the serial header.

Others have had similar issues that were EMI related and have had luck using ferrite filters, and/or spike suppressing diodes to kill transient spikes caused by motors or heaters turning on and off.

I went back to the basics and installed the simplest serial firmware I found in arduino, and even simplified it to echo what I type.. but I am getting the same error, and the microcontroller even crashes!!!!!
Unfortunately, I don't have a 16 MHz crystal at hand to try a lower speed.. but for now, am gonna take bryanandaimee advice and redo the serial parts..
Will keep you updated in case someone is interested or has the same problem as mine.
Regards

SOLVED...
and in small letters, it was my fault all along
I have assembled the board about 2 months ago, and since I didn't find any 22p capacitors for the crystal, I settled with 10p (I never gave those two capacitors much respect before), but now I do respect them.

Off to continuing assembly of the printer..

& THANKKKSSS to all who have helped