WFS210 tested and this product has issues ! Request for support comment

Instruments WFS210
1

Dear Velleman Product Support,

Reference the WFS210 wireless DSO

I have long been a very impressed and satisfied customer of your test equipment product lines. I raised an issue with the trigger on your HPS140i DSO and you released a fixed version of the firmware - excellent service.

I recently purchased a pair of your WFS210 wireless DSO’s from Maplin Electronics in the UK. I thought it such a neat wireless DSO solution that I raised its availability on the venerable EEVBlog forum where electronics designers, professionals and hobbyists meet. There was much interest in my posting and several purchases of the WFS210 resulted from it.

Having tested the WFS210 I and my fellow EEVBlog forum members are discovering some serious issues with the product. Whilst the hardware appears to be of your usual high standard, the firmware and software appear to leave a lot to be desired and are still very buggy. Little development, if any, appears to have been done on this product since 2014.

Please will you advise whether this WFS210 product is still being supported by your developers or is it now considered ‘abandoned’. If it is still being supported, I am happy to provide the bug reports from the EEVBlog forum.

I hope you will understand that, having highlighted this product to forum members, I feel responsible for them potentially wasting their money.

Bug list to date:

  1. The WFS210 is often not seen by the Android APP even though the Wi-Fi link has connected and an IP address confirmed. This issue can make the unit frustrating to setup and unuseable in many cases.

  2. The Android APP 5us 2us and 1us timebases appear to have an issue with 5us being the smallest available and the 2us and 1us selections making no change to the timebase.

  3. The PC software has no Y shift capability for the two channels.

  4. On the PC software there are two triggers and these can introduce a false phase difference between the channels if both are moved away from the baseline point. Surely only one channel trigger should be active at any one time ?

  5. The WFS210 apparently locks up after 15 minutes of non use and requires a reboot. A power saving function ? but no auto-recovery from it ?

The most serious bug by far is the inability to link the Android App with the WFS210. I personally have experienced this infuriating problem. It appears that the APP cannot see the WFS210 in spite of a solid Wi-Fi link and IP address allocation. It then immediately enters ‘DEMO’ mode. Multiple deactivations of the DEMO mode using the setup menu will eventually lead to a successful connection and correct operation of the APP and WFS210. Many users would have given up on the unit by that time though.

The units that have been tested to date contain the following firmware:

Main firmware : 1423
Wi-Fi firmware: 4.0
Android App: 1.2

Main firmware : 1443
Wi-Fi firmware: 4.41
Android App: 1.2

I look forward to your response on this matter.

Fraser

2

The EEVBlog discussion thread for the WFS210 may be found here:

http://www.eevblog.com/forum/testgear/vellerman-wfs210-wireless-oscilloscope-for-only-20-!/

Fraser

3

The timebase error effecting the 2us and 1us ranges in the Android App has been traced to a programming oversight that needs correcting.

Please see here:

Reply 48 on this page

http://www.eevblog.com/forum/testgear/vellerman-wfs210-wireless-oscilloscope-for-only-20-!/msg1315226/#msg1315226

There may also be some progress on why the WFS210 does not reliable connect with the App.

One forum member has already voiced doubts that you are going to respond constructively to me on this matter. Let’s prove him wrong eh ?

Fraser

4

Hi

Thank you for explaining everything in details.
We’re sorry you’re having issues with the WFS210.
I had a look at the EEVBlog forum and changed the code a bit.

wfs210
wfs210979×429 37.6 KB

As for point 5. The WFS210 will go to sleep if there isn’t an active connection for 15min

5

Wonderful,

Thank you so much for the engagement on this and for confirmation of the sleep mode.

On point 4, regarding the apparent twin trigger … it is a mistake in the user manual. Your user manual states that the two yellow sliders on the PC software are trigger 1 and trigger 2. This is in error. The sliders are the channel 1 and 2 Position shift controls. The Trigger is the Solid line that is shifted using the mouse to select and pull it up and down. A fellow forum member discovered this.

I shall continue to highlight issues and potential corrections that are discovered by the EEVBlog forum members so that you may consider applying solutions and improve your product.

I regret that it is getting a bit of a “bashing” on the forum, but I believe some relatively simple changes may make this a very useful little DSO of which you will become proud.

Best Wishes

Fraser

6

Can you please address the connection issue as well as that is a serious issue that impedes using the WFS210.

On the EEVBlog forum you will see that the APP is sometimes too quick to look for the ‘* Hello *’ response from the WFS210. One forum member has overcome this by entering a delay entry into the Apps code.

Please can you replicate this entry in your release of the Android App.

I hope this constructive, and hopefully helpful feedback is of interest to you. We can make this product better :slight_smile:

Fraser

7

An extract from the EEVBlog forum from member Avacee who is very kindly helping to improve your product.

“After a successful connect it reads 7 bytes from the input stream and looks for HELLO (inc 2x *)… if it doesn’t match then it throws an error and you go into demo mode - and good luck ever connecting.
I’ve seen this failing in the debugger and within WireShark whereby the data returned is sometimes H ELLO (8 bytes) <— note the space.
Also what can happen is the unit doesn’t respond quickly enough so when the input stream is read it is still empty as it reads the data immediately upon connection.
The code doesn’t keep waiting for the hello via a timeout … it reads nothing and fails”

Fix from Avacee :

“Regarding the Hello message … a suitably placed Thread.Sleep() means I go straight into Live Mode as it gives the unit time to reply.”

8

I’ll add a bit to this from further debugging.
It appears to only goes into LiveMode if I exited in LiveMode - I think the default should be to always start in LiveMode and I’ve changed the code downloaded from Github on my machine for this.

The Thread.Sleep helps with the HELLO Welcome message but I was still having Connect() failures. (though fewer).

I massively reduced these by not using the AsyncWitHandle but by passing in a new AsyncCallback(CallBackMethod) object and then calling the EndConnect in the callback (which is the method recommended in Microsoft’s documentation).
It still needs a small Thread.Sleep just before (or in) ReadWelcomeMessage()
I’ve just tested 50 back to back successful connections straight into Live Mode and 50 flipping back and forth from demo to live.

Inspiration (aka copy->paste->hack) for more reliably network connections:
https://www.codeproject.com/Articles/31514/Implementation-of-Connecting-a-Socket-with-Timeout

9

Slightly off-topic but I added some local functionality I think would assist;
There’s no way (that I know of) to centre the vertical offset so I added a LongClick to the Channel1+2 buttons
Code:

MainActivity.cs
LoadControls() … Add these 2 lines
btnSelectChannel1.LongClick += HandleCH1LongClick;
btnSelectChannel2.LongClick += HandleCH2LongClick;

New Routines:
private void HandleCH1LongClick(object sender, View.LongClickEventArgs e)
{
_ScopeView.CentreChannel(1);
}
private void HandleCH2LongClick(object sender, View.LongClickEventArgs e)
{
_ScopeView.CentreChannel(2);
}

In SignalView.cs
public void CentreChannel(int channel)
{
if (channel < 1 || channel > 2) return;
Markers[channel - 1].Value = MapSampleDataToScreen(125);
ApplyMarkerValuesToScope();
}

10

Another owner from the EEVblog forum here.
I’d just like to say thank-you for responding to this thread and I look forward to a new version of the Android App.
I do like the idea of this kit, and once the software is updated it will be of great use to me.

Jim

11

@Avacee Thanks for the tips!
Do you have link to your GitHub fork?
If you feel your code is stable don’t hesitate to do a pull request.

12

Just an FYI.
The Form Application is not the PC application. It’s probably an accidental creation of the project. You can ignore it.
The PC Application is written in Delphi.

13

For point 3, you can do the Y-shift by moving the yellow balls next to the scope screen.

wfs210_y
wfs210_y897×617 79.8 KB

As for point 4, I’ll pass this along to the software developer.

14

Hi Vel337,

Thank for the responses. Much appreciated.

Regarding those yellow sliders for Y shift in the PC program. They are shown as the Trigger 1 and Trigger 2 level setting sliders in the manual. Hence the initial confusion.

Are you awaiting anything from the EEVBlog forum members or do you have enough information to correct the problem with the WFS210 connecting in the Android App ? It would be great to get the App to be more reliable as this will surely reduce or even eliminate customer return cases for your retailers. Whilst I and others on the forum are happy to work with you to improve the product, other customers will likely be impatient and just return the unit.

Best Wishes from the UK

Fraser

15

Hi Fraser,

Yes, I’m currently waiting on releasing the Android app.
I’ll check the version from Avacee tomorrow. If it suffices. I’ll push it to the Play Store
EDIT: if Avacee could submit a pull request. I can check the software.

Best Regards
VEL337

16

Dear Vel337,

I am pleased to hear that a new App release may be in the offing :slight_smile:
I am aware that Avacee is intending to check his code before he releases it. He is otherwise engaged this week but I feel sure he will do the upload to you as soon as he confirms all is well.

Best Wishes and thanks again for engaging on this matter. I am already hearing a more positive attitude regarding the product since you responded to my request for help :slight_smile:

Fraser

17

Just FYI
We’ve released the firmware :wink:

18

VEL337,

Thank you for doing this. It is much appreciated :slight_smile:

Fraser

19

Dear VEL337,

I am acutely aware that now you have released your firmware, you are at risk of someone copying your design if you also released the schematics.

With this in mind, would Velleman be willing to release the part of the schematic that details how the input ground connection becomes raised to +1V6 with respect to USB ground when the unit is connected to a USB supply. This may be part of the input channels schematic or the USB charger/supply schematic.

Any information you can provide would be greatly appreciated. We might find a way to overcome the USB ground to Input ground differential as it can be a problem to users.

I will also be writing to you regarding the HPS140i in that units forum as I need your help on that unit as well :slight_smile:

Best Wishes

Fraser

20

Hi

Sorry, i can’t give you the schematics.
I’ve seen on the EEVBlog forum they were missing the bootloader hex file.
That was my mistake, the gitignore file removed the file.
I’ve updated it and should be live now.