Ok, I'm looking into some dsp shields. Do you think I might need a data logging shield?
I get modules instead of shields and wire them with jumpers. I got LC modules very cheap directly from the company. They take 5V (signal and power) and 3.3V power (might not have to but I jumper it) and work with the SPI and SD or SdFat libraries. You have to email LCTECH and ask how much for however many you want. I bought more than 10, there is a small shipping and PayPal charge. OTOH the same modules can be found on eBay and at DealExtreme for not a whole lot and DealExtreme takes credit cards.
I buy direct 1 or more of many modules from LC at a time so it's not a hassle for me. They do have VS1053 DSP modules for voice record and play but I wanted MP3 player capability which turns out needs a solder mod I don't dare try. I can't say if they work right off the bat for voice recording or about the quality but here's a blog on the mod to play MP3's from a member on this forum:http://www.bajdi.com/lcsoft-vs1053-mp3-module/
All the hacks below should work on Arduino with the SPI and SD or SdFat libraries.
You can make your own SD module pretty cheaply. One way is to get a full size SD adapter for micro-SD card and solder directly to the contacts. Hardest part is voltage-shifting from 5V to 3.4V (plus or minus .3V is okay) which isn't a big deal. If you run the AVR at 3.3V it's not needed at all. 3.3V will make an Arduino 5V pin go HIGH so no need to shift up from the card to the Arduino.Lot of good breadboarding tips here
, the "ghetto micro-SD socket" is about halfway down. http://www.protostack.com/blog/2011/09/8-breadboard-hacks/
However; Tip 1, on my small breadboards the power and ground rails go full length.
This site shows one of those with level shifters on a proto-board. Did he even spend $5?http://nathan.chantrell.net/20111128/diy-micro-sd-shield-for-arduino/
I would 'build' the resistors right into the wiring. That's what heat shrink is for, right?
This one is neat but involves unnecessary work.http://www.instructables.com/id/SDMMC-fits-in-floppy-edge-connector/
Instead of opening the connector and taking it off the cable then making a custom cable and clamping the connector back... why bother? The next connector down the cable has holes perfect to jumper or plug a male header strip into. What can I say? I use old floppy cables for wire buses, they have 34 lines and multiple connectors, just watch out for the one with the twist or cut it off. It still needs a few resistors or diodes to go 5V to 3.4V.