Is Smith chart planned?


#1

Hello,

I’ve been looking for a cross-platform app that could visualize measurements from antenna analyzers and VNAs. AE6TY’s SimSmith is the best app so far. But, unfortunately, it can’t connect to devices to control them directly. It takes only files in Touchstone format to visualize.

Today I’ve found Wizkers, the very promising platform to become a de-facto interface for many measuring tools. Though it is still missing many useful features. For example, a Smith chart in js/app/lib.

Maybe anyone is already implementing Smith chart? If no one, I have no choice but to start working on it. But I don’t think I have enough free time to implement and contribute it in a reasonable amount of time.


#2

Thanks!

Yes, smith chart would be super useful. Right now the “flotplot” lib (based on flot) can do a lot, but only linear graphs. A quick search on Google led me to this: http://cemulate.github.io/smith-chart/ . I need to look at the license (Wizkers is MIT) and see whether this is compatible, or alternatively, if this can be used as an inspiration for creating our own smith chart plotter.

I agree, this can be a fairly time-consuming task to implement, but is needed…


#3

I have contacted the developer of the Smith Chart plugin I mentioned above, and he’s 100% OK with us reusing it in Wizkers - I am putting together a Smith Chart library this week-end, probably not enough time to have something that works properly by Sunday, but you never know!


#4

A bit of Sunday morning work. It’s not very difficult to draw the background, now I need to add the methods to actually draw on top of the chart. It’s a start, though:

Edit: and now, I have basic plotting too (using a Sark110):


#5

Just finished the first implementation tonight!

Below, an example of the chart with a VSWR circle (green dashed) for SWR=2.

And another example with my 20m dipole (no SWR circle drawn on that one):

I will include this in the next Wizkers:Radio release, in time for the week-end if all goes well!

Comments are most welcome: what do you want to see on a smith chart to make it as useful as possible for you?


#6

Looks great, Ed!
But I am in Seoul now and will stay here till mid-September, so I will be able to try connecting my RigExpert compatible device only after returning. 73!


#7

@JJ : if you are a javascript developer, by all means you are most welcome to contribute to the code, I can help you out if you want to write a RigExpert plugin, it should be very straightforward.


#8

No, I am firmware engineer. Mostly using C/C++. But I have some experience with Node.js since it is used in some of our testing automation frameworks, the only inconvenences with it are debugging endless nested callbacks and floating point numbers instead of integers under the hood.