G'day one and all,
Is there a hack around to run the Diecimila on 3.3v only? If so could someone point me in the right direction.
Thanks,
Stephen...
G'day one and all,
Is there a hack around to run the Diecimila on 3.3v only? If so could someone point me in the right direction.
Thanks,
Stephen...
The actual ATMEGA168 chip can easily run at 3.3V but not at 16Mhz. So, the solution is to replace the 16Mhz oscillator with something slower. The chip can run at 1Mhz with it's built in timing circuit (or 128KHz if you want). If that's too slow you might be able to get something else. You really have to look at the Mega168 spec sheet and find a Mhz rating that is fast enough for your needs but will run at 3.3V.
Keep in mind that if you change the Mhz you will also change all of the timings of things. Serial communications will become problematic very easily. I don't know how well the arduino delay functions will work.
I suppose I'd need more information about what you are trying to do and how fast you need the chip to run to be able to say much of anything concrete.
i THINK (no responsibilty taken), that you could do this if you were willing (and have the hardware) to reload the bootloader.
[1] Choose "Lilypad" in the Tools->Board menu drop-down
[2] Connect a ISP programmer to the board and choose Tools-> Burn Bootloader
[3] Feed a REGULATED 3.3V to the decimilia "5V" and "GND" pins
Changing the bootloader to the lilypad makes the arduino run off the internal oscillator. Feed the regulated 3.3V into the Vin pins bypasses the on-board 5V regulator.
Changing the bootloader to the lilypad makes the arduino run off the internal oscillator. Feed the regulated 3.3V into the Vin pins bypasses the on-board 5V regulator.
No, the Vin pins go to the on board regulator's input.
Lefty
Yep you are right sorry -
Use the pins labelled "5V" and "GND".
Changed in my previous post
Thanks that guys,
That seems fairly straight forward.
What about when plugged into the USB? isn't that a 5V source?
Regards,
Stephen...
What about when plugged into the USB? isn't that a 5V source?
Yes, USB is 5V so if you want to power a 3.3V board off of it you'd need to use a regulator or a voltage divider.