Well you will need a level shifter when using the SPI in hardware for the SDI pin. 3.3V is just not high enough for the Schmitt inputs on a 5V PIC. I'd have to check the datasheet but I recall it's something like VCC-0.8 (4.2V) is a 1.

Use the Logic tool (TTL level won't really show Schmitt level triggers) to watch those SPI signals. See if they match up with what you're getting.

I'm trying to get this to work as well. I'm using a 3.3v chip, though, so level translators aren't my issue, but I thought I'd keep this all in one thread.

I have tried a microsd card and a few regular sd cards. On the microsd card setup, I have nothing pulled up. On the SD card setup I have the unused data lines pulled up.

I'm getting no response from the card at all. I've tried quite a few variations with changing the way I'm working the protocol, and delays and such, but still nothing from any of the cards.

Here's my logic output for the initialization. I send 10 0xFF's to get the initialization clocks over with, then I send the CMD0. 0x40,0x00,0x00,0x00,0x00,0x95. I check 20 times for a response before resending this initialization, and continue to get the same no response.

Logic view:
http://www.higginstribe.com/z8e/sd-connect.png

I'm hoping someone can see something that I can't otherwise I'm just going to have to keep experimenting.

Setup:
http://www.higginstribe.com/z8e/sd-connect.png

EDIT: Actually, I just checked my setup again, and only the unused pins on the SD card breakout are being pulled up. Pin 9 and 8. Otherwise the datalines are direct connect. Edited text above.

Hang on, am I reading your MISO right - is it all 0xFF's. do you have your MISO set as an input?


Is this a PIC?

Mark

p.s. nice logic analyzer by the way

Here's the circuit for the full size SD breakout board. I made this a couple years ago and never got around to it again, so it's kinda messy, but I've confirmed all the pins connect properly. The pullup resistors on the MISO and MOSI lines in the schematic are not attached on the board, so they are not active. Pullups for line 8 and 9 are attached.

Otherwise the other side of the lines are connected directly to the uC. There is obviously nothing wrong with the CLK, SS, and MOSI lines as they are working fine. I would think that even if there was an issue with the MISO line, I would still see data transmitted on the Logic, it just wouldn't process on the uC. For some reason that data line is just held high.

http://www.higginstribe.com/z8e/sd-breakout.png

Yes, MISO is an input. It's a hardware SPI block and I just set it to go. I will double check everything in the code to make sure I'm not resetting that pins function or anything.

If I disconnect MISO from the uC all together, I get the same result. MISO is held high the entire time.

This is not a PIC, it's a Z8 Encore.

Remember the SPO on the SD card is driven not open collector so pullups won't help.

Sparkfun uses this design on one of their level converter designs.

Probably, it's a simple enough circuit. I've not tried it myself but I have used the 74HCT125 with success.