I am working on a home made bike computer. I have a Mega664 and a load of peripherals eg lcd, i2c rtc, polar HR reciever i2c barometer, uart (debuging) and wheel, crack and button inputs all these are working OK.
I have added an SD card using the futurlec mini board and I can get it to work so long as I do not have the SPI connected up to my Dragon at the same time. The Dragon only works reliably if I have the SD disconected. I have tried various combinations of series resistor to get both working together but have not got it reliable although I have got close enough to think it must be possible.
The one thing that I have that is slightly unusual is that there are two seperate 3.0V power suplies. One for the mega and rtc and one for all the other peripherals. The mega controlls this secondary suply so I can shutdown when idel. I was hoping this would help as when in reset the secondary suply to the SD card is off.
Anyone know if this should work? What would be the recomended conection setup?