Otii Arc Pro overview

An advanced look at the Otii Arc Pro - technical specifications

As shared on the Otii Arc Pro page, this is a compact and portable tool with comprehensive technical features for energy optimization of battery-driven and energy-harvesting devices. As a multi-purpose tool, it serves as a power supply, measurement unit, analyzer and debugger, making it the must-have addition for everyday use on any hardware, firmware and software developer’s desktop.

With Otii Arc Pro and Otii 3 Desktop App, you can source the voltage of the device under test (DUT) up to 5V while simultaneously measuring and recording current, voltage, and power data in real-time for further analysis to optimize battery life throughout the development cycle.

To elevate the Otii Arc Pro's capabilities for product development, test and verification, quality assurance, and maintenance, explore Otii Toolboxes, a set of specialized licenses that can be purchased as perpetual or subscribed to on yearly or monthly basis.

Hardware overview

The front side of the Otii Arc Pro has the main connectors, additional ports to extend measurement capabilities, plus a status LED.

The back side of the Otii Arc Pro has the host USB connector and an input socket to power up the unit with an external DC adapter when required.

Main connections

The Otii Arc Pro has the voltage(+) and voltage(-) binding post (red and black connectors located on the right side of the instrument), which are used to source the DUT but also to measure the current, voltage, and power of the device. The DUT can be connected through its battery connectors or DC input; refer to the connection diagram below for better understanding.

To power up the Otii Arc Pro and enable communication with the host computer, connect the unit to your computer using the provided micro USB to USB A cable.

Check out the Wiring up page to explore all possible connection configurations between the Otii Arc Pro and your DUT.

Expansion Port

The expansion port on the front of the Otii Arc Pro is designed to enhance the hardware's functionality, allowing users to measure additional voltages and currents or trigger external events. These additional pins feature multi-input and multi-output for analog and digital signals, serial communication, and additional power and ground points. Below is a general overview of the additional pins available:

ConnectorDescriptionMaximum rating


5V output

500 mA


Digital ground (return current)


UART RX / Digital Input (Exclusively under Scripting)


UART TX / Digital Output (Exclusively under Scripting)


Digital input #1

0V - 5.5V


Digital input #2

0V - 5.5V


Digital Output #1

0V - 5.5V


Digital Output #2

0V - 5.5V


Digital ground (return current)


Analog ground (return current) | Analog measurements


Differential input for current measurement. It also measures single ended voltage with respect to AGND

0V - 5.5V


Input for current measurement

0V - 5.5V


Analog input with the AGND as reference/return

0V - 5.5V


Analog input with the AGND as reference/return

0V - 5.5V

In case of using the expansion port, checking out the entire technical specifications for all the details about each available pin is highly recommended.

Status LED

The table below explains the Otii Arc Pro's status LED behaviors and their meanings to help you quickly identify the device's state.

LED behaviorOtii Arc Pro Status

Flashing green

Otii Arc Pro is active

Solid green

Relay closed, sinking/sourcing power

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