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Arduino voltage regulator and other questions.

 Hello, I have a few questions I hope somebody or several people can answer :)


1- I am thinking of integrating an ATMega328 /128  IC to a PCB I'm planning to build for a project which I want to make as compact as possible, but I am not sure if I need the voltage regulator with it's two capacitors as shown here: http://fritzing.org/projects/barebones-arduino/I was thinking of using button batteries and fix the voltage to something like 6 or 9 volts. Do I need a voltage regulator for that? does arduino only work at 5V?

2- I know I'll need the crystal and it's own capacitors, though I'm thinking of using this instead

which I think substitutes the need for the two 22pf capacitors, right?


3- and the last ones, can I use the ATMega328 - TQFP with the same components shown on the first link? , and can the arduino bootloader be uploaded to it with just the serial adapter? 

 thanks in advance! 

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1 Yes you will need a voltage regulator. If you are running at 6v you should consider a low dropout vreg as they can usually run on close to the same or higher voltages. if running at 9 then a 7805 or similar would work. you should use both caps with any reg.

2. Resonators are fine and do not require caps. They aren't as accurate as a crystal but until you are making a mars rover for nasa, you may not necessarily need to use crystals.

 3rd question, the 328 tqfp is compatable with the 168 but if you don't have expirience with soldering small components I'd not recommend it. as far as getting the bootloader on it, you'd need to use an icsp connection to upload to the 328. From my understanding the serial cable won't work.




thanks for the reply,


about the last question, maybe I didn't explain myself well, I meant one of these adapters,



would it be possible to program the small TQFP with that thing just like you would do with the bigger brother ATMega168?

You can program any ATmega chip with the Arduino bootloader, with that.  You can also use it for many other things than just the Arduino's, all it is, is a USB-to-Serial connector. (You can get the FTDI breakout board, EXACT same chip, but it has the RESET line brought out., and it's like $10 cheaper!)

The key words are WITH A ARDUINO BOOTLOADER. That wouldnt work on those atemga's above because they do not have a ARDUINO BOOTLOADER on them. This has the arduino bootloader on it https://www.sparkfun.com/commerce/product_info.php?products_id=8846 so you would need to get that one.

yep, I forgot to say that it was uploading the bootloader  to  the ATMega328 - TQFP  what I needed,


what is needed to do it?   


edit, I just reread voodoo's post and it says a icsp connection, forgot to google that. 

edit 2:  I think it can be uploaded like this, not sure though.


From my understanding, you need to burn/install it to the chip via an isp programmer. Once it you have it loaded you can use your serial adapter to program the arduino'd avr.
thanks,  I think I will get the larger chip with the arduino bootloader preloaded then.

1 If you are running 6VDC straight from the battery, you can damage the processor, as most MCU's (AFAIK) run from 2vdc-5.5vdc. That extra half volt can fry it. You will want a 5VDC Regulator, or a 4 pack of RECHAGEABLE BATTERIES, NOT ALKALINES. Rechargeable batteries have a typical cell voltage of 1.2VDC, and in a four pack equals 4.8VDC, which is perfect for MCU's.

2.Resonators are basically a crystal and cap all in one with 3 pins.

3. Do not start with TQFP. All noobs (no offense,we were all noobs at one time) think that soldering is easy, and soon discover that the 0.1" spacing is a lot closer than it looks. Start with through hole components.

no offense taken, I'm a noob in these matters indeed, but I am kinda stubborn :D  so I will give it a try anyway, plus I have some basic experience soldering PCB, I created a shield recently with satisfactory results.

  I found this nice tutorial that makes it look easy enough, although I know it's going to be tricky.

and thanks for the info, I think I am going to use a regulator and a 9v input or something along those lines.


funny avatar btw, 300 + che guevara lol.