STM32F4 Discovery, SPI and microSD

Well what do you know, it is working! :)

Wandering in the wilderness

Since my last post I delved right down into the SD specification to try and figure out what should be happening. I found a few particularly helpful posts and documents that I'd like to share here for others having similar problems:

1. SD Specifications - Part 1 - Physical Layer - Simplified Specification - Version 4.10
   
2. Reading SD cards with the STM32F4-Discovery
   
3. Micro SD Data Sheet
   
4. Secure Digital Card Interface for the MSP430 - Dept. of Electrical and Computer Engineering, Michigan State University
   
   

and it even got me ferreting through the C code ;)

Thanks to reference #2 above I found out what should be happening with the card detect (CD) pin when the card is put into the slot. Everything was in order.

Still no joy!

For some reason I decided to use another set of pins and see what happened. This is the current standing of the SD definition block in boards/STM32F4DISCOVERY.py:

  'SD' :  { 'pin_cs' :  'D7',
            'pin_di' :  'B5',
            'pin_do' :  'B4',
            'pin_clk' :  'B3' },

I connected her up, ran my command and this is what I got:

>var f = require("fs").readFile("test.txt");
="hello\n\n"

followed by a write just to make sure it really was working:

>var f = require("fs").writeFile("blah.txt","hell­o");
=true

So I'm not quite sure what is wrong with the other set of pins but at least it is now working and I have learnt a bunch of stuff I never thought I'd have to!

Thanks again for all your help @Gordon.