Ultimate GPS Shield on 3.3v Leonardo
Moderators: adafruit_support_bill, adafruit

Ultimate GPS Shield on 3.3v Leonardo

by ontrack on Tue Oct 29, 2013 5:50 pm

Before buying an Ultimate GPS Shield I am concerned about two potential incompatabilities.

Can I run the shield on 3.3v power and data signals? I know both the GPS and SD actually just need 3.3v. But I am not certain the design of the shield has assumed 5v power and data signals by default.

Would the SD card run on SoftSPI when the shield is connected to a Leonardo? Because it seems to assume that SPI is on pins 11, 12, 13. But they are only available via ICSP on the Leonardo.

If anyone could provide their opinion on this.
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Re: Ultimate GPS Shield on 3.3v Leonardo

by adafruit_support_rick on Tue Oct 29, 2013 6:32 pm

The Ultimate GPS Shield works on Leonardo. The Leo is a 5V device.

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Re: Ultimate GPS Shield on 3.3v Leonardo

by ontrack on Tue Oct 29, 2013 7:04 pm

How about a Leonardo-pincompatible board like the Olimexino-32U4? This can run on 3.3V and allows for Li-ion battery.
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Re: Ultimate GPS Shield on 3.3v Leonardo

by adafruit_support_rick on Wed Oct 30, 2013 7:23 am

I'm not familiar with that board.

However, the shield requires 5V in. The 3.3V pin is not connected.

Internal logic levels are all 3.3V. The TX and MISO output lines are 3.3V.

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Re: Ultimate GPS Shield on 3.3v Leonardo

by ontrack on Wed Oct 30, 2013 9:57 am

Could you also provide information about the SPI connections of the shield? Because the Leonardo-design does not have these pins on the same place as the Uno-design etc.

Thanks in advance.
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Re: Ultimate GPS Shield on 3.3v Leonardo

by adafruit_support_rick on Wed Oct 30, 2013 10:13 am

The SPI connections on the shield are the same as for the Uno. With a Leonardo , you must use software SPI to communicate with the SD card.

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