Can the target power be controlled by a GPI?

Technical Discussion
1

I’d like to be able to disconnect power to the DUT under certain conditions which I can distill to a digital signal.
I’d like to have this functionality work during a recording - I’m not sure if that adds complexity so better to state it.
I’d like to do this within the UI - I suspect it may be feasible currently with Python, but I didn’t see a way to do it within the UI.

2

Hi @Jeremy - The quick answer is that the Joulescope UI does not do this today. You can easily write a Python script for this, and the Joulescope UI’s PubSub architecture makes this easy to add.

Do you want to turn off power to all connected Joulescopes on a single GPI, or only to same Joulescope that has the GPI?

For one Joulescope, you need to publish to
/registry/JS220-XXXXXX/settings/target_power

Replace JS220-XXXXXX with your actual device.

For all Joulescopes, you need to publish to
/registry/app/settings/target_power

To get a sense of how things work, you can manually publish using developer tools:

  1. Click the Settings icon on the sidebar
  2. Check UI → developer
  3. Select Widgets → PubSub Explorer
  4. In the new PubSub Explorer widget, navigate to registry → JS220-XXXXXX → settings → target_power
  5. At the bottom, type false (this takes any valid JSON), then Publish

As of today, I see this being an “advanced” feature that should not normally be exposed. I see a few ways to accomplish what you want:

  1. Extend the Trigger widget with an Advanced mode that allows you to directly publish [topic, value] pairs for Start Actions and Stop Actions. The Set output action publishes like this today.
  2. Create a custom plugin.
  3. Create a socket-based API for the UI that allows other programs to publish & subscribe. Create a publish-only socket server is very easy with Python. This may be better if the source is another program toggling a GPO.

What do you think?