# Differential Gauge Node, a proposal for a new appearance

**URL:** <https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449>\
**Category:** Dashboard\
**Created:** [9 February 2020 11:31 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449 "2020-02-09T11:31:12Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![Robertotarga](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/robertotarga/32/16890_2.png) [@Robertotarga](https://discourse.nodered.org/u/Robertotarga)\
**Post date:** [9 February 2020 11:31 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/1 "2020-02-09T11:31:12Z")

</div>

I'm using latest Dashboard v. 2.19.4.  
Gauges/Donuts work very well when the range minimum value is not negative.  
In my case I'm using a dashboard flow to display the electric power exchanged between grid and solar PV panels in my home. When you produce more than you consume the ehchange value is positive ( you are selling energy to the grid), whereas it's negative if you consume more than you produce ( you are buying energy from the grid). So, when setting up the node, a negative value has to be inserted in the minimum field, say -6 kW and +6 kW for the maximum.

In this situation the gauge/donut display is very unintuitive, if not misleading. For instance if no power is echanged (payload =0) you still see half sector filled with color and you may think that half power of total range (-6 kW-6kW) is exchanged while it's actually 0!

 ![Comparison0](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/8/e/8e94f002a6a327036ad4d46a2b765124a0306389.jpeg)

As you can see in the following screeshots the gauge rapresentations with power = -5kW, 1kW and +5 Kw are equally not meaningful. For instance, if you are buying 5 kw from grid, you just see a tiny red sector whereas it should be at its almoust maximum extension:

 ![Comparison-5](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/7/f/7ff7988070de962c913c660db0ebe2ff5683ebd6.jpeg)

On the right side of every screenshot I have proposed what in my opinion should be the correct representation.  
What I'm proposing here is a sort of "differential" gauge.  
It should have following behaviour when a negative minimum value is set in the minimum field :

- with value = 0 the needle is in vertical position ( a "zero" digit on central top of gauge would alse be nice to have)
- with value \< 0 the circular sector is drawn **counterclockwise** starting from zero vertical position
- with values \> 0 the sector is drawn **clockwise** from zero.

Is this behaviour achievable with some particular node configuration/tweaking? if so please help me.

If not, I'm proposing to the Dashbord/Gauge team to add this new "differential" appearance. From a UI perspective it will suffice to add in existing node configuration window a checkbox "Use differential appearance", enabled only when a negative value is inserted in the Minimum field. So you can keep actual behaviour if you like it more.

HTH  
Note: I also had screenshots of 1 kW and 5kW scenarios, but I couldn't post more than two images here. I will if someone is interested in the topic.

---

<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [9 February 2020 12:12 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/2 "2020-02-09T12:12:03Z")

</div>

interesting - but I think it would need changes to the underlying justgage library first in order to "move" the start point to be your zero point at 12 o'clock.

---

<div class="post-metadata">

**Author:** ![Robertotarga](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/robertotarga/32/16890_2.png) [@Robertotarga](https://discourse.nodered.org/u/Robertotarga)\
**Post date:** [9 February 2020 13:48 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/3 "2020-02-09T13:48:09Z")

</div>

Hi dceejay,  
Glad that you like my idea. Is there a chance that someone will convert this suggestion into an upgrade to current gauge node?

---

<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [9 February 2020 13:55 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/4 "2020-02-09T13:55:02Z")

</div>

Always a chance... but as I said it would need the Justgage project to pick it up first to allow that to happen.

---

<div class="post-metadata">

**Author:** ![Paul-Reed](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/paul-reed/32/66906_2.png) [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)\
**Post date:** [9 February 2020 13:56 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/5 "2020-02-09T13:56:25Z")

</div>

Would be something that @robertsLando may be interested in.

---

<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [9 February 2020 13:58 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/6 "2020-02-09T13:58:39Z")

</div>

already DM'd him

---

<div class="post-metadata">

**Author:** ![Robertotarga](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/robertotarga/32/16890_2.png) [@Robertotarga](https://discourse.nodered.org/u/Robertotarga)\
**Post date:** [9 February 2020 15:49 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/7 "2020-02-09T15:49:21Z")

</div>

OK dceejay. I'm a newbee here and I hope @robertslando will pick it up. At disposal for further information.

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [10 March 2020 15:49 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/8 "2020-03-10T15:49:23Z")

</div>

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.

---

<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [1 December 2022 22:34 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/9 "2022-12-01T22:34:19Z")

</div>



---

<div class="post-metadata">

**Author:** ![Tortax](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/tortax/32/42704_2.png) [@Tortax](https://discourse.nodered.org/u/Tortax)\
**Post date:** [14 February 2023 09:36 UTC](https://discourse.nodered.org/t/differential-gauge-node-a-proposal-for-a-new-appearance/21449/10 "2023-02-14T09:36:17Z")

</div>

I see this option has been implemented now. "Fill gauge from centre" has been added.  
But it only works for a differential and it has to be symmetric. Otherwise you will end up with a weird looking gauge. I opened a request [Request](https://discourse.nodered.org/t/gauge-property-fill-gauge-from-centre-assumes-a-symmetric-differential-range/) to fix this.