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Stalker v3.1: Question re: I2C selectable voltage

Posted: Thu Jan 17, 2019 3:50 am
by pbanders
The Seeed product page for the Stalker v3.1 says:

"I2C Pin header (operation voltage is selectable: 5.0V or 3.3V)"

How is the voltage selectable? There's no switch or pad to disable the level shifter? Can this be done or is this spec in error?

Re: Stalker v3.1: Question re: I2C selectable voltage

Posted: Fri Feb 01, 2019 4:47 pm
by bestlux
Hello,
Do not worry, look at the shifter circuit in schematic there. When you plug in grove of 3.3V or 5V directly, the circuit will match the level automatically.
Image

Re: Stalker v3.1: Question re: I2C selectable voltage

Posted: Sun Feb 03, 2019 6:26 am
by pbanders
Thanks - maybe that's obvious to you that the level shifter handles this automatically, it isn't to me! When I read the VCC pins in the Grove sockets, I see 5V. I don't seem to have any 3.3V Grove devices, so I'll take your word for it. Thanks again for your reply.

Re: Stalker v3.1: Question re: I2C selectable voltage

Posted: Sat Feb 09, 2019 10:39 pm
by designnotes.com
pbanders wrote:
Thu Jan 17, 2019 3:50 am
The Seeed product page for the Stalker v3.1 says:

"I2C Pin header (operation voltage is selectable: 5.0V or 3.3V)"

How is the voltage selectable? There's no switch or pad to disable the level shifter? Can this be done or is this spec in error?
Hi,

When they say selectable then it means then it will work in the range of this voltage. Like in Arduino it is written that its operating voltage is 7-12 volts it means it works on any voltage in between this range. But it depends on your load if the load is HIGH then your device will not be able to handle that load.


https://store.arduino.cc/usa/arduino-uno-rev3