The uMP3 Playback Module is 2.5 inches by 2 inches (6.35cm by 5.08cm).

Short answer: up to 8KBytes/second.

Long answer:

Writing speeds will vary widely depending on the type of make/model card you're using. There are a lot of different factors that can affect the speed of the card.

To maximize the throughput to the card, try following these guidelines:

Open a file on the uMMC/uMP3 for writing, start the write command (for 512 bytes - e.g. on the uMMC "w 1 512"), then send the data as you get it. Of course, you should keep track of the number of bytes you have already sent, and be prepared for a delay after the buffer is completely full on the uMMC/uMP3.

Essentially, this is what you will do:

1. Open a data file for writing/appending (e.g. on a uMMC "o 1 a /data.txt").
2. Start a write command (e.g. on a uMMC "w 1 512").
3. Collect data, then send to uMMC/uMP3 (keep track of how many bytes you've sent).
4. After 512 bytes have been sent, it will take some time for the uMMC/uMP3 to commit the data to the SD/MMC card. You may want to buffer 5 to 10 packets of your data during this time.
5. Go back to step 2.

I hope this makes sense. In this way, you have the ability to use the buffer on the uMMC/uMP3 to store much more data at a time.

The time it takes to commit the data to the SD/MMC card varies widely with the speed/brand/size/format of card used. It is recommended to always check the module's response before sending a new command.

Yes. You can find the chipset pricing for the uMMC/uMP3 on the product information page. You can also find information on integrating the chipset under the download section of the product information page.

The uMMC/uMP3 hardware uses a LDO (Low Drop-Out) voltage regulator. You can use 3.0V or 3.3V as the input voltage, but you need to ensure that the serial lines do not exceed the supply voltage (3.0V or 3.3V respectively).

For file creation, the uMMC/uMP3 only accepts the 8.3 filename format.
e.g. FILENAME.EXT

The uMMC/uMP3 does, however, accept long filenames for reading.

EF2 happens when the file in the path does not exist.
e.g. Opening a file for reading that does not exist.

EF5 is essentially the same as EF2, but something in the middle of the path does not exist.
e.g. /DIR1/BADDIR/LOG/FILE.TXT - where BADDIR does not exist.

EE7 occurs when you open a file, but the path specifies a directory.

The life span for a uMMC/uMP3 unit is only limited by the contact wear on the MMC card connector - which is rated at up to 12,000 plug-in cycles.