As per title do I need a voltage regulator to build a standalone arduino circuit or can I use a voltage divider as the required voltage of the ATMEGA328 is 1.8V to 5.5V according to http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1848694.
I did post a related topic in the product guidance forum but as I haven't received any response I decided to re-post here as this forum seems more relevant.
You definately don't want to use a voltage divider. Most people prefer a linear voltage regulator like the LM7805. Or use a switching regulator module. It would waste much less power. You will need to check the specs of your regulator for input/output voltage. Much depends on what you are using it for.
http://www.dimensionengineering.com/info/switching-regulators
Check this one out:
OR
If you're new to electronics and arduino, you'll be much happier and probably more successful with an arduino module with built-in voltage regulator.
Here's a link to a similar topic:
http://arduino.cc/forum/index.php/topic,23460.0.html
ElectronicsNoobie:
As per title do I need a voltage regulator to build a standalone arduino circuit or can I use a voltage divider as the required voltage of the ATMEGA328 is 1.8V to 5.5V according to http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1848694.I did post a related topic in the product guidance forum but as I haven't received any response I decided to re-post here as this forum seems more relevant.
You don't need to use a voltage regulator, but it is on you to be sure voltage can not exceed 5.5vdc or you risk chip damage. Don't try and power a chip with a voltage divider, it not the proper way to provide power to a chip.
Lefty
I am fairly new to electronics, but I want to learn how things work. Thanks for the link about voltage regulators I didnt realise that a lot of their utility came from their efficiency rather than their accuracy. That makes a lot more sense.
Next time I put a parts order in I will make sure it includes some more voltage regulators.
ElectronicsNoobie:
Thanks for the link about voltage regulators I didnt realise that a lot of their utility came from their efficiency rather than their accuracy.
There are two types of regulators: linear and switching. The link you read talks about why switching is more efficient than linear.
So no, it is not correct to say their utility is more about efficiency than accuracy. The correct use for a regulator is to provide an accuracy voltage source. You should a switching regulator when efficiency is important.
If you tell us what you are going to use to power your stand alone arduino circuit and what your output current will be, we can be more specific about what regulator you might use.
I plan to power the project using a 9v battery. It will power a small LED matrix (5x5) and will be driving the LEDs at around 5ma, as I am row scanning so only max of 5 LEDs will be lit at a time. As its a small matrix at lowish power I am going to drive the matrix directly from two 595 shift registers. I am using a ATtiny25v microcontroller to provide the brains.
I am planning to use a http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1087086 as a voltage regulator (thanks to the advise on this forum) that maybe a bit overkill as it can provide way more power than I need but I have one going spare in my parts box as well as the necessarily capacitors.
It's not overkill it is standard practice, that is why they are so cheap.
However 5mA for an LED on for only one fifth of the time is going to be rather dim.