External DC power monitor

Does anyone know of a project or USB device that could monitor DC wattage, power, amps, of an external source like a battery, solar, etc?

I'm looking for a USB device that has external connections to monitor a DC source.
In turn, I can get that data from the openwrt device then do something else with it like sending it to a central monitoring system, etc.

This isn't really an OpenWrt question since the hardware you're looking for wouldn't really run or be related to OpenWrt in any specific or unique way.

I'd recommend asking on more general forums, especially those that deal with power monitoring (in all seriousness, a "prepper" site may be a great source of info for these types of monitoring devices).


I asked here not for support but thinking this is where openwrt users are.
There are tons of openwrt projects which is why I figured asking here would be the best place.
Asking about openwrt on a prepper site would be a heck of a long shot :slight_smile:

Well, you're not asking about OpenWrt on a prepper site... you're asking for a DC power monitoring device on a prepper site. From there, you'd have some specific devices to look into for potential use with OpenWrt.

Why are you discouraging me from posting here, where the openwrt community actually is?
Why not invite posts that involve using openwrt. There are lots of projects that use openwrt and maybe someone has or is doing this.

My apologies if it didn't come out quite as intended... I'm only half doing this...

On the "discouraging" element -- I do understand you are aiming to integrate a solution with OpenWrt, but this is the type of thing that is slightly off topic in that it isn't specific to OpenWrt. I wasn't outright saying "don't post here" but rather pointing out that the hardware you seek is somewhat unique and specialized and isn't really the target of these forums. (it would be very different, and completely on topic if it was network equipment that you plan to pair with OpenWrt).

But on the part of encouraging you to ask elsewhere -- I honestly think you'll get better answers and engagement from other sources that may have a greater number of users who have specifically researched and used these types of products. So that was intended to be a helpful suggestion, not a flippant statement.

Understood. The thing is, OpenWrt users are here, in these forums.
Maybe there needs to be a new forum for projects and things that people have and are doing with their openwrt based devices. That would be great.

We have a forum category for Community Builds, Projects & Packages. But it still needs to be relevant to OpenWrt specifically, and your proposed project is something that could be done using literally any computing platform. (Like a Raspberry Pi, Arduino, etc.)

If instead you asked, for example, about making a daemon or a LuCI app on OpenWrt that can monitor uninterruptible power supplies, that would be something more on-topic for the OpenWrt forum.

you can build your self a power monitoring device using esp32 and using a firmware called tasmota.

I did find this:

There's no notes of Linux compatibility, but OpenWrt does include the HID drivers and libraries. In general simple USB devices like this that work with Linux can be fairly readily run on OpenWrt.

This sort of hardware is more properly called a datalogger. Searching for "USB voltmeter" will find lots of things that measure the voltage and current flowing through a USB bus, which is not what you want.

Yes, I also use Tasmota and ESP devices but was looking for something where I could use openwrt specifically as the OS.

Yes, correct, I searched repeatedly but could not find anything as related as I was after.

I'll take a look at this and thanks for the key word ideas. I'll try those as well.
Something like this with an ESP chip on it communicating using the wifi on an openwrt device would be a good solution though Ethernet would be fine too.
There are so many $20-30 dollar devices running openwrt.

Maybe once I find a device, then I can see if it might work using openwrt.

How about INA260 and use MQTT on OpenWrt? (But people usually use it with Home Assistant)

My thought is to use an openwrt router to receive all of the sources I'm monitoring then in turn, forward that to a central app I would use.

I have a full MQTT implementation and will probably build my own Graphina or other method to display. Home Assistant is just another thing I have though not yet using it much.

That's interesting, thank you.