Hi guys,
I am trying to make a pcb with the w5100 ethernet controller along with the atmega328p-pu on a single board.
Now I see that the atmega runs on 5v and the wiznet on 3.3v, so for the SPI communications to work do I need a level shifter for 3.3v to 5v conversion or its not necessary?
Also what if I run the atmega on 3.3v? Will that work?
Thanks
any solutions people?
I want to run the atmega 328p-pu from my duemilanove board at 3.3 volts using 16MHz. Will it be a problem? Will I have to flash some other bootloader or I can use the current one?
Hi there,
Ok so I just came to know that the W5100 pins are 5v tolerant so I won't need a buffer IC.
I have attached my schematic and board files. I still have to add the reset controller.
What do you think about the board guys?
It would be great if I could run the atmega328 at 3.3v/16 MHZ.
Any of you done this before?
Thanks
mqtt.sch (972 KB)
mqtt.brd (190 KB)
Just a tip: Post images, not schematic files. Not everyone uses the same software (not entirely sure what format these are -- assuming Eagle?), and even for those that do have the software, having to download a file before someone can determine whether they can / are willing to help is a bit much to ask on a busy forum.
Also, I don't mean to be condescending, but based on your questions, I would venture that you may not be ready for this project. If you're prepared to deal with medium-speed differential signalling and the like, you don't usually have to ask for advice on how to best power and level-shift logic circuits.
As a practical skill assessment, are you using jacks with integrated magnetics, or are you using an external isolation solution? Is it compatible with auto-MDIX? Will you be using PoE, and if so, does your isolation mechanism provide the appropriate sense resistors? (If none of that makes sense, you might want to stick to a prebuilt module until you've researched this design a bit more.)
Again, no offense intended, and if you're really gung-ho on trying this yourself, don't let anyone (least of all, me) stand in your way. Just friendly advice that might save you some time, money, and frustration.
ssd_20072:
It would be great if I could run the atmega328 at 3.3v/16 MHZ.
Any of you done this before?
Take a look at the iBoard by iTeadstudio. http://imall.iteadstudio.com/im120410001.html
Cheap and they're doing what you want to do. Look at their schematics for ideas on how to do your own. I have used a few of the iBoards and I like them but what I'd really like to see is an iBoard with arduino shield footprint and 5V/3.3V selector switch/jumer. I have a project now that I'd like 5V on the arduino IOs.
BTW, are your files Eagle 6? My Eagle 5 can't open them.