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Topic: Oak Micros om328p Arduino Compatible (Read 5 times) previous topic - next topic

ziplock

No, he's asking why the board doesn't have a 3.3V supply pin (coming from the FT232 or an external reg).

Mike Perks

The om328p does not have a 3.3V supply pin from the FTDI chip simply because there is not enough available pins in a 28-pin package. That is also why AREF is tied to Vcc. The internal voltage reference is still available of course. It is simply a matter of compromise to fit everything into a standard 28-pin 600 mil socket.

I would also argue that the 50mA limit from the FTDI chip 3.3V output is somewhat limiting.

It is definitely possible to provide a version of the om328p with a 3.3V regulator and 8 MHz crystal. It would take a little PCB work to change the power routing for the FTDI chip. As I mentioned before this is not a showstopper and would simply a matter of reaching sufficient sales to justify the cost.
Mike Perks
oakmicros.com
See our om328p Arduino Compatible

CrashingDutchman

Hmm, I was not asking for just a 3.3V supply pin. I was more looking into something that Seeedstudio did with their Seeeduino.

It has a switch which can be set to either 5V or 3V. When switch is set to 3V, everything will work on 3V. Not just a supply pin, also the other pins.

Mike Perks

#13
Jul 07, 2009, 08:27 am Last Edit: Jul 07, 2009, 08:28 am by mikeperks Reason: 1
Thank you for the clarification CrashingDutchman and your continued interest in the Oak Micros om328p Arduino compatible.

The Seeduino has much more space on its PCB and can offer such an option. The om328p is designed to be very compact but yet socketable and breadboardable. It is also priced very competitively with other Arduino platforms. As in any design, some compromises were made and there is very little space to offer a 3V/5V switch or solder jumper.

One great thing about the Arduino platform is the wide range of devices and boards that use the same software tools, platform and design - you can pretty choose the features that match your application. The om328p sister product (ZX-328nu) and the ZBasic platform is another example of this idea.
Mike Perks
oakmicros.com
See our om328p Arduino Compatible

CrashingDutchman

My initial post that said "missed chance" maybe was a little harsh. Be assured that this wasn't my intention.

I understand completely about the size and that you are limited in adding components. I don't want to push you into a direction but, I think there is a market for a similar product as yours, but running at around 3V.


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