MKR Connector Carrier Groove connector voltage

According to the Getting started page the Grove connector pin 3 provides “Power to module 5V/3.3V”. What determines the voltage provided on the digital IOs D0-D6?

I measured the voltage on the Grove connector for D2 to 5V. I’m currently supplying 3.3V to my device from the Arduino MKR WiFi 1010 VCC pin. How can one supply 3.3V to the digital Grove connector?

All the I/Os are supplied at 5V and the carrier provides the proper 5V to 3.3V level shifting.

power and signal levels are 5 V on Grove connectors on the Carrier.
wire 3.3 V devices to MKR header.

Thank you. What does “the carrier provides the proper 5V to 3.3V level shifting” mean?

the shield has logic level conversion IC so the signal pins of D pins are converted between 3.3 V of Arduino and 5 V of connected device both ways (input or output).

on A pins the are voltage dividers to lower 5 V input to 3.3 V for analog pin of the MKR. It would disturb digital output on A pins.

additionally for unknown reason there is a capacitor on A pins which makes it impossible to sample fast changing analog signal like 50 Hz of AC over a current sensor.

the signal pins of D pins are converted between 3.3 V of Arduino and 5 V of connected device both ways (input or output)

The device I’m using is a Maxim DS3431 1-wire EEPROM. It can accept up to 5.25V. Do I understand correctly that by connecting it to 5V and the shield’s signal wire (e.g. D0 pin1) to the EEPROM’s signal pin, the shield will convert the signal 5V voltage to 3.3V for the MKR board?

is your EEPROM a plain IC or is it a module with some supporting circuit?

It’s on a board with a few discrete components on it in addition to the EEPROM. I got it to work as connected in #5.