AVR-Chat

Hi,

    I am getting crazy with a board that I made with a ATMEGA8 and a AD595
thermocouple interface. I get one good reading and a whole bunch of crazy
( usually 0 ) readings from the AD converter !!! Follows a list of things
that I tried to solve the problem and none of them makes any difference. The
program is a one liner with just the printf of the readings and a delay...

- Tried different types of AD routines using codevision codewizard:

    - tried simple, no interrupts.
    - tried interrupts.
    - Interrupts with noise canceller ( sleep mode )
    - direct inline code for getting the readings.
    - Changed the sampling frequency to all options.
    - added huge delays everywhere.

- Changed the reference from internal to AVCC.
- Changed the power supply to a good old 7805.

    The darn thing is so constant the it seems like a software error
somewhere but that does not make sense either because I am using the
codevision codewizard code to read the ADC.

    Please... Please... Does anyone have any more ideas ?

    I also tried to put some huge 4700 mF capacitor and a bunch of ceramic
ones just to make sure there is no huge noise on the supply lines.

    The output from the AD595 is ok, measured with a fluke multimeter...
With a scope it is ok also...

Best regards,
Alexandre Guimaraes