Two quick but specific questions

Hey all, I'm a bored high schooler about to start a multi-part project. I've worked all the code and schematics out, but there are two small questions I have due to my lack of experience with arduino interfacing. If you guys could help me out with this, I would be really grateful.

  1. Ok, this is the more specific question, and it might be impossible to answer without trying it out, so apologies in advance. My project will need to be able to record and playback audio in real-time. This is the only arduino shield I can find with the potential to do this. http://www.makershed.com/ProductDetails.asp?ProductCode=MKSKL3 (I realize it could be made easier with a different microcontroller, but I want to do this project with an arduino for certain reasons) This shield uses the Winbond ISD4003 voice chip, commonly used in recording 8kz audio for greeting cards and the like. It records sound in .2s chunks in successive addresses, which the arduino can locate. (Limited shield documentation: http://www.spikenzielabs.com/SpikenzieLabs/VoiceShield.html)

So, let's say I have a 4 second soundbyte. My arduino calls this from it's starting address until the EOM marker inserted by the VC. My question is, what kind of lag are we talking about between the time this is called and the time it begins to play? What about if I call it every 4 seconds, would the VC likely need additional time to seek the beginning of the soundbyte? I don't have much knowledge considering flash memory access times, so let me know if anything needs to be clarified.

  1. Ok, my second question is a bit simpler. I will be using an arduino uno. My entire project will be powered by a rechargeable lipol/liion, and I want to be able to charge it via the same USB port as the arduino's serial, without having to remove the battery. There are several USB charging boards I've seen, but I have no idea if they can be left connected to the battery while the arduino is running off of it; is there any reason they couldn't? Additionally, the arduino and another low-current device will be running at 9V off the battery, but arduino-size lipol/liion batteries seem to have an either higher or lower voltage than 9v; so what's more efficient to make them 9v, stepping them up or down? Do you guys have any tips for me concerning battery type/configuration?

Thank you very much!

Thanks for your reply!

This is the board I'm specifically looking at: http://www.cutedigi.com/product_info.php?products_id=4353

The batteries can't be much larger than the Uno; everything is going to be in a relatively small enclosure.

The Uno does operate on 5v, but the specifications page lists Input Voltage (recommended) as 7-12V. The other device is a sealed smoke detector, build to run off a 9v cell. So, 9V would work perfectly for both.