1. Overview#

1.1. Affordable, easy-to-use, accurate and precise#

Multimeter view

Oscilloscope view

Multimeter view

Oscilloscope view

Applications include:

  • Microprocessor and microcontroller power profiling and optimization

  • Hardware power optimization

  • Sleep current optimization

  • Hardware and software troubleshooting

  • Software characterization and interrupt service routine profiling

  • USB 2.0 inrush and suspend current pre-compliance testing

  • General-purpose current, voltage, power, charge, and energy measurement

The Joulescope™ JS110 is the most affordable and easy-to-use precision DC energy analyzer. It measures current and voltage, then computes power and energy. Many modern battery-powered devices and IoT devices have a high dynamic current range, which makes accurate measurement difficult. When “sleeping” the devices consume nanoamps (nA) or microamps (µA), but when active, they consume milliamps (mA) or amps (A). Joulescope combines high-speed sampling and rapid dynamic current range switching to provide accurate and seamless current and energy measurements, even for devices with rapidly varying current consumption. The unprecedented accuracy and low-cost of Joulescope allows every engineer on the team to measure the energy consumed by the target device during development. Joulescope provides rapid feedback on how changes affect the overall product battery life.

Joulescope displays instantaneous voltage, current, power, and energy, like a multimeter. The multimeter provides a quick and easy summary of the present state of your device.

Joulescope displays waveforms of voltage and current over time, like an oscilloscope. This oscilloscope view allows you to identify and to troubleshoot dynamic behavior and short events, including inrush current, event handlers, and tasks.

1.2. Key benefits#

  • Dynamic range: Joulescope accurately measures electrical current over nine orders of magnitude from amps down to nanoamps. This wide range allows accurate and precise current measurements for modern devices. Sleep modes are often just nanoamps (nA) or microamps (µA). Active modes are often milliamps (mA) or amps (A).

  • Low voltage drop: Most multimeters and current meters have a significant voltage drop (sometimes called burden voltage or insertion loss), which affects the actual voltage delivered to the device under test. Joulescope has a total voltage drop of 25 mV at 1 A, which keeps your target device running correctly. Joulescope’s extremely fast current range switching maintains low voltage drop even under rapidly varying current demands.

  • Makes the invisible visible: Joulescopes measure current and voltage 2 million times per second with 250 kHz bandwidth. This high sampling rate makes the power consumption of interrupt service routines, inrush currents, and other short events visible.

  • Easy to use: Joulescope reports cumulative energy consumption along with real-time current, voltage, and power. The multimeter view clearly shows the most recent value, while the oscilloscope view allows you to explore changes over time. Much simpler and more accurate than anything in its class!

  • Customizable: The Joulescope host software is open source on GitHub. You can also swap the banana jack front panel with front panels that have other connector types. The front panels are open source on GitHub.

  • Portable: Joulescope fits in your backpack and only needs a small part of your desk. Take Joulescope wherever you want to use it!

  • Affordable: Joulescope is affordable and priced so that every developer on the team can have one at their desk. With such convenient access, Joulescope allows developers to see the impact of their changes on energy consumption immediately. Developers can make informed choices to account for battery life during design. Eliminate power consumption surprises during final product testing!

1.3. Key features#

  • -1V to 15V voltage range

  • -1A to 3A current range, continuous

  • Up to 10A current pulses (<10 ms, < 3A average per second)

  • Down to 1.5 nA resolution, equivalent to 32-bits of dynamic range

  • Synchronously measures voltage and current at 2 million samples per second, 14-bit

  • 250 kHz bandwidth

  • Rapid 1 µs switching between shunt resistors for seamless dynamic current measurement

  • Computes power, total energy, and charge

  • Operates with minimal voltage disturbance between IN and OUT ports

  • Up to ±48V common-mode voltage between USB ground and IN-, IN+, OUT+, and OUT-

  • 2 general-purpose inputs and 2 general-purpose outputs

  • Programmable on/off for power cycling the target device and measuring inrush currents

  • USB 2.0 high-speed host connectivity

  • Host software support for Microsoft® Windows®, Apple® Mac® OS X®, and Linux®

  • Host software provides real-time graphs of current, voltage, and power over time

  • Host software is open source and available on GitHub

  • Swappable front panel with open-source designs on GitHub

  • Firmware upgradable

See Section 4 for the full specifications.

1.4. What comes in the box#

Your Joulescope JS110 purchase includes:

  • Joulescope JS110 instrument

  • Banana Jack Front Panel, already installed

  • 6’ USB 2.0 A to B cable

  • T15 Torx screwdriver

  • Quick Start Guide

  • Joulescope sticker

You will need to provide:

  • A host computer running one of the supported platforms. Most computers manufactured within the last five years should work. The computer requires an available USB 2.0 port, at least 500 MB of hard drive / solid state drive storage space, and 1 GB of available RAM.

  • Suitable cable(s) to connect Joulescope to your power source

  • Suitable cable(s) to connect Joulescope to your target device.

You need an internet connection to download the free software.