schematic review/check (help?)

Using Arduino Project Guidance
1

hey gang-

I added/edited some things on my older schematic I'm getting back to finally..

I added in a power led and an led on pin 13 (like default).....

as well as (the biggest change) swap out the uSD socket I'll be trying to use.

the pinout naming is a bit different than the original uSD socket component I used (which was easy to follow)..

so Im hoping to get some feedback and possibly some help if its wrong.. (mainly the switch to the Adafruit uSD socket from an old Sparkfun uSD socket)

here are some quick pics (as well as the schematics)

thanks!

orignal socket used:

694×611 80.8 KB

new socket Im updating to:

694×611 74.2 KB

link to both schematics:
http://dmstudios.net/misc/sd_change/compare.zip

2

1 NC
2 ChipSelect (buffer down to 3.3V)
3 MOSI (buffer down to 3.3V)
4 +3.3V
5 SCK (buffer down to 3.3V)
6 GND
7 MISO (buffer if there will be 5V devices on the line also)
8 NC
CD1 NC
CD2 NC
MT1 GND
MT2 GND

3

hey Robert-

thanks for the reply..

ok.. so i can delete the CD2 (card select) trace I have there.. (as its NC)

I have it as follows:

SD: CIRCUIT:

PIN 1/DAT2 NC
PIN 2/CS PIN2/A1 on buffer
PIN 3/DATA IN PIN3/A2 on buffer
PIN 4/VDD 3.3v (after cap)
PIN 5/SCLK PIN4/A3 on buffer
PIN 6/VSS GND line
PIN 7/DATA OUT PIN5/A4 on buffer (already going to buffer.. no telling what devices may be hooked up to the board in the end)
PIN 8/DAT1 NC
CD1 NC
CD2 NC <------ removing this one (originally had it going to GND)
MT1 GND
MT2 GND

thanks for the second pair of eyes.. :slight_smile:

4

The way the CD lines work, they close a switch when a card is inserted. The software is supposed to check to see if the pin is open or closed. So you could connect both together and bring that to an input pin, and maybe the library you use checks for it, or maybe it doesn't. I think the better libraries will do read test from the card to see if its responding correctly.

If you have one of the sockets, you could put a meter on the pin and Gnd on the socket, see if putting a card on closes the switch(es) or not.
Sometimes one of the pins is Write Protect, you could try that out too, see if putting some tape or similar over the write protect notch (or whatever uSD/SD cards use) and see there is any change in switch status.

5