Hi, I was looking at potentially buying the joulescope. It looks perfect for my
use case, but I wanted to make sure of it, before buying.
I have an IoT device that is in deep sleep most of the time, drawing
~121uA. When it is on, it connects to WiFi and draws ~70mA. It is capable of
charging through a USB and other means as well.
I want to be able to measure the charge in mAh, with the test possibly lasting
weeks to months. I expect it to accurately display the charge. For example,
charge consumed increases when discharging, and charge consumed decreases when
charging (I’ve had bad luck with battery emulators…).
Is this something the Joulescope can do along with the UI? Thanks!
Yes, the Joulescope was designed to accurately measure these currents and integrate to compute charge (and energy). If you only want to see the total, you can use the Multimeter view, like this:
You can also record these same statistics over time to a CSV file by pushing the button indicated with an arrow. You can also downsample, say to 1 kHz, and record to our proprietary but open source JLS file format for later viewing in the Joulescope UI.
Yes, all the Joulescope hardware and software performs proper integration. The instrument is full 4 quadrant, ± current, ± voltage.
The Joulescope UI uses SI units by default, but you can select customary units like this:
We also provide the downsample_logging script. This provides a resume feature in case anything goes awry, such as power loss or host computer reboot.
If you are using Windows for the host computer, you can follow our guide for Performing long-term captures on Windows. In all cases, you should at least disconnect networking to prevent updates from getting in the way.
When you purchase from The Joulescope Store, we offer a 45-day return policy. If you decide within 45 days it’s not right for you, we will refund the purchase price, including standard shipping fees. I hope you give the JS220 a try!
