problem arduino as master for home automat

Hello,

I am struggeling for 2 months now with the following, please help me:

I run a arduino Mega2560 with 0021 software.

This arduino should act as a master system for home automation:

  • time syncronisation from internet
  • connection to ethernet for confihurring + reading data file from sd card
  • datalogger temperature and power from salves (jeenodes)
  • receiving slave messages via RFM12 module
  • PID thermostat for controlling heating
  • display infomation on display

So I have the following hardware:

  • arduino Mega 2560
  • new official ethernet/sd shield from arduino (version 2)
  • RFM12 module connected to mega
  • LCD display

All works well, but is unstable.

It looks like every time a write to the SD card is done , and the rfm module receive a slave message , the program hangs. Maybe this is only a thought.

I cant't get it stable. I've tried:

  • all parts + software seperated, it works individually perfect
  • all parts together and all software (except the code for receiving RF messages): works perfect
  • as soom as I enable the code to receive RF messages the arduino hangs after 30min-2h.

i've tried disabling interuppts before accesing SD card, but still no improvement.

Now I doubt that it even is possible to get this stable. How should I proceed to debug ?

Can you give some advice, because there are not a lot of experts how have experience with this kind of setup.

Many thanks in advance,
Jeroen Meeussen.