SPI potential issue

[Dr_Doggy]

on my pic, I am using the SPI bus to use several 5v devices, but at the end of the bus there is my SD card, but is only at 3v so for this I use resistors to drop the volts going in to the SD Card,, but then on the DataOut pin(from the SDcard, since it is at 3v(above threshold of pic) the schematics say to wire it direct to the pic,

but I fear that when another device sends data to the pic it will also send 5v to the SDdataOut pin, I assume this would damage SDCard??

I want to use a diode so volts cant get in to SDdataPin, but then doesn't that drop the the SDdata out value to 2.3V, which is under pic I/O threshold(??), would adding a capacitor after the diode help? or is there another simple solution??

 

[Sceadwian]

2.3V should NOT be under the PIC I/O threshold. Look up the specific threshold on your PIC.

 

[aussiepoof]

If you use a schottky diode you'll find the voltage drop across it is lower.

 

[Dr_Doggy]

thnx guys, ima let it slide then!

 

[Dr_Doggy]

IZ gotta nother issue so ima just post it here;

my masters code is locking up on spI send, can a master tick when disconnected(having spi unplugged will only input 0's not lock it up right)?

If that is the case I will need to check my code........?