Hi everyone - I'm using an SM5100B cellular shield (http://www.sparkfun.com/products/9607) for Arduino. The module apparently can draw up to 2 amps or even 2.5. However, I'm fairly new to electronics, so I'm not sure what the best way is to achieve this.
From one tutorial (http://tronixstuff.wordpress.com/2011/01/19/tutorial-arduino-and-gsm-cellular-part-one/):
It is highly recommended that you use an external 5V power supply capable of delivering 2A of current – from an AC adaptor, large battery with power regulator, etc. ... When connecting this supply DO NOT use the DC socket on the Arduino. Instead, connect the 5V (positive) from the supply to the 5V pin on the GSM shield, and the negative to the GND pin.
Here are my questions:
- Why not supply this power from the DC socket?
- What is a good rechargeable and portable power source for this? I read somewhere that a regular 9V battery won't cut it because the voltage will drop quickly. Is this the case? Not to mention the fact that I imagine a 9V battery can't supply 2 amps.
- Any recommendations on an AC adapter that would do the trick? I'm not sure where to begin.
- Is it correct that I can use something other than a regulated 5V power supply as long as I connect it to the VIN pin instead of the 5V pin?
There are likely some other things I'm missing, so I welcome any thoughts on this.
Thanks a lot.