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[on:]

I'm looking for information about low power arduino. Almost everything I find is about using an atmega8L.

Does anyone know why I cant find anything about arduino using atmega168V ? It is because it's a "new" ic or am I missing something ? (It can run at 3.3 too and I guess it can be slowed down to 8Mhz with the same modifications)

thanks

[Reply #1 on:]

hi

have you looked int he playground? There is this, is it enough?
http://www.arduino.cc/playground/Learning/Atmega83-3V

 I think there are some hardware differences with the 168V that would have to be accounted for in software...

edit: seems like they are pin for pin compatible inside and out. You just need to feed it all the logic-level signals at 1.8V!
AVRFreaks has a nice comparison table page here:
http://www.avrfreaks.net/index.php?module=Freaks%20Devices&func=devCompare
D

[Reply #2 on:]

I have an ATmega168v-10PU chip sitting here on my desk.
I'm planning to put the Arduino bootloader on it using my USBtinyISP (http://www.ladyada.net/make/usbtinyisp/index.html), but I have a couple questions of my own.
Will I be able to use it in my NG board? I think that if I change the bootloader and the makefile so that it runs at 8Mhz it should be OK.

[Reply #3 on:]

yes, that and you'll need to change the crystal to 8mhz... other than that it should work fine at 5V.
What will you do to program it when you run it on 1.8V? I don't think you can run the FTDI usb chip lowers than 3.3.
 
D

[Reply #4 on:]

yes, that and you'll need to change the crystal to 8mhz... other than that it should work fine at 5V.
What will you do to program it when you run it on 1.8V? I don't think you can run the FTDI usb chip lowers than 3.3.
 
D

I thought that if I set it to 8MHz that it would use its internal oscillator. I hope that would mean that I wouldn't have to mess around with changing XTALs. I wasn't particularly looking at low power applications myself, I just want to be able to use ATmega168V-10PU chips because I can get them cheap locally.

[Reply #5 on:]

I didn't think of that, very sneaky solution

D

[Reply #6 on:]

Well, I managed to get the 168V to work with my NG board just fine.
That was pretty satisfying actually, since it was the first time I have attempted to burn the bootloader and the first time I have tried to use my USBtinyISP kit.
Now I know how people can get so excited over getting that LED to flash.  
For the record, the fuses I used were:
Low: 0xFF High: 0xDF Extended: 0x00

I found the e-textile page very helpful for getting a better idea of setting fuses for low power
http://www.cs.colorado.edu/~buechley/e-textile_kit/e-textile_kit_tech.html

slanbuas, I encourage you to give it a try, the 168V looks pretty good for low power use. If you look at the datasheet, a 168V running at 1Mhz uses only .55 mA, compare that to the idle current of the standard Arduino at 20ma - not bad!

[Reply #7 on:]

Thanks, seem pretty interesting ! I'll try to play with it

[Reply #8 on:]

My understanding is that  the L and V suffix parts are identical die to the normal parts, but tested to operate correctly at the reduced voltage levels, and within the reduced current specs.  (this is true of many of the microcontrollers with "low voltage" parts.)  This (if true) has a couple of useful consequences:

1) normal parts without L/V suffix may still operating at the lower voltages.  The WILL operate at lower current levels if the clock frequency is reduced; perhaps as low as the L/V parts.

2) L/V parts will probably work at full speed (of the "high power" parts) if they are also operated near the top of the voltage range (5V)

A lot of "low power optimization" for microcontroller projects in general consists of keeping most of the chip turned off (or operating very slowly) when it isn't specifically needed for something. The arduino core code, using approximately 1ms interrupts from timer0, is not particularly well suited to this sort of thing...