Author Topic: Velleman WFS210 wireless oscilloscope for only £20 !  (Read 54471 times)

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Offline R_G_B_

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #50 on: September 30, 2017, 12:56:13 pm »
Firmware version 1443

WiFi firmware 4.41

App version 1.2

The android software responded  like a  corpse

I don't know how this got into mass  production

I'm sure there are people on this forum who can write much better software

I agree we Fraser the idea of this is a good one shame about the effort.

It's obvious velleman were aiming to high on this one.



« Last Edit: September 30, 2017, 01:01:03 pm by R_G_B_ »
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Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #51 on: September 30, 2017, 01:28:33 pm »
For info,

My WFS210 is serial number 091400311

Firmware 1423 and Wi-Fi firmware 4.00

Android App is 1.2

Fraser
« Last Edit: September 30, 2017, 01:34:35 pm by Fraser »
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Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #52 on: September 30, 2017, 01:35:45 pm »
I have another WFS210 to test

Serial number 111400814

Firmware 1423
Wi-Fi firmware 4.0

Fraser
« Last Edit: September 30, 2017, 01:38:12 pm by Fraser »
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Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #53 on: September 30, 2017, 01:47:31 pm »
Testing of both WFS210 units on my HUDL tablet....... both linking to Tablet with ease !

Test repeated many times with same result. None of the delay in creating the link that I had yesterday.

So what has changed since yesterday ?  Location, location, location.

I have moved further away from my house Wireless Access Point.

I am starting to think the Wi-Fi module used in the WFS210 is part of the connectivity problem, if not THE problem.

More testing needed though. I will try connecting when near to the AP.

Fraser
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Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #54 on: September 30, 2017, 02:05:45 pm »
Nope, I cannot explain this.

The exact same equipment in the exact same location now links and works without any problem  :-//

The only change to the WFS210 is that I connected it to my laptop via Wi-Fi and USB cable to test it.

Remember that the unit worked flawlessly on the first switch on yesterday. It then went flakey on me.
Could there be some form of firmware or APP instability I wonder.

I carefully watched my tablet while it created a Wi-Fi link to the unit. It sees the SSID soon after the Wi-Fi LED starts its slow blink. When told to link to the WFS210, the tablet quickly displays the IP address so that is already established before the APP is running. The link LED became Solid on. This is all before the APP is started.

Once I start the Android APP, the display is NOT in Demo screen mode and the IP address appears at the bottom of the screen. The DSO is then running fine. I repeated the link process from scratch several times on the two WFS210 units and they worked flawlessly today. Soooo weird  :-//

Fraser
« Last Edit: September 30, 2017, 02:09:38 pm by Fraser »
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Offline R_G_B_

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #55 on: September 30, 2017, 03:17:49 pm »
Fraser

Any chance of monitoring the network activity between the tablet and
The velleman WiFi oscilloscope and the host device?

How about using a spectrum analyser to look in the frequency domain see if there are any problems there as well.

Need a protocol analyser to look at where things in a bit more depth instead of plug and pray.

Just some ideas
R_G_B
 

Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #56 on: September 30, 2017, 03:28:04 pm »
I can do Spectrum checks but sadly I do not have a Wi-Fi link protocol analyser.

I have quite a few more interesting projects (thermal cameras) at the moment so I cannot spend too much time on this cheap little unit. I will do some more analysis of its behaviour though.

I also need to check the basic performance of the DSO and its trigger stability etc.

I am just a little baffled as to why it started behaving so badly yesterday, yet today it is connecting fine every time I test it.

Your unit looks to have a later firmware loaded. It would appear that the update made no difference to the units connection reliability if yours is still misbehaving.

Fraser
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Offline R_G_B_

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #57 on: September 30, 2017, 03:44:51 pm »
I think I have Found something but need to see if this is the same for others

When on the android tablet and connect to the velleman WiFi scope it's intermittent switches between demo mode and connected mode. And the interface does not respond.

Using the tablet with  OTG connection to velleman scope alone again just goes into demo mode. However when I simultaneously connecting using both the usb OTG connection and WiFi it works flawlessly.

I'm not sure why this is but it seems to make the thing work.
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Offline R_G_B_

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #58 on: September 30, 2017, 03:52:09 pm »
I suspect the software is getting. confused with the connection type some how its timing out or hanging ..while decided the  connection type

Just a thought
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Offline jimmc

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #59 on: September 30, 2017, 04:10:43 pm »
Another WFS210 here from Maplin/ebay

Serial number 101400580
Firmware 1423
Wi-Fi firmware 4.00
Android App is 1.2

Tablet running Android 4.1.1


Having trouble with initial connection but once established seems reliable.

A quick check suggests a front end bandwidth of 20MHz @-3dB,
but with a fastest sweep speed of 1uS/div* and no anti-aliasing filter
the maximum usable frequency is about 1MHz.

*Now what? The 5, 2 and 1uS timebase settings all give a sweep speed of 5uS/div,
the numbers may change but the trace doesn't!
I've checked this using a few frequencies around 100kHz so I don't think it can be an aliasing problem.
Can anyone confirm this?

Jim
 

Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #60 on: September 30, 2017, 04:11:03 pm »
R_G_B,

AFAIK the APP does not use OTG connectivity.

BUT I was thinking along a similar line. When I first tested my unit it was still on charge and worked flawlessly. I then tested it on my function generator whilst it was running on its internal battery. The fun began there.

I was considering whether the fact that the unit was being powered from a nice solid 5V was making it more reliable. OTG supplies power to the connected device too.

My tests today were with the first unit self powered and the new unit on charge. Both behaved.

Could we be seeing a noise problem due to the battery boost circuit I wonder ?

These are useful observations. Keep them coming :)

Fraser
« Last Edit: September 30, 2017, 04:13:02 pm by Fraser »
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Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #61 on: September 30, 2017, 04:14:55 pm »
Jimmy,

Welcome to the madhouse that is the WFS210 owners club  ;D

Sadly I am literally heading out the door to a party, so cannot check your issue.
If not confirmed today, I will take a look tomorrow.

Fraser
« Last Edit: September 30, 2017, 04:28:05 pm by Fraser »
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Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #62 on: September 30, 2017, 04:15:58 pm »
Was the WFS210 an apprentice project that never got finished I wonder ?

Fraser
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Offline bitseeker

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #63 on: September 30, 2017, 07:16:49 pm »
Hmm, running on battery is a plausible source of instability. Wi-Fi is power hungry.
TEA is the way. | TEA Time channel
 

Offline Avacee

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #64 on: September 30, 2017, 07:50:13 pm »
Firmware 4.00 and Build 1423.

I can consistently make my unit freeze and would appreciate if others could repeat the test.

1) Turn on the unit and give it a minute to fully boot. I know the "AP Ready" LED starts blinking straight away but be patient :)
2) Start either the Windows or Android App - Connect via Wifi - Wait for waveform to appear - Disconnect
3) Do nothing for 15 mins (seems pretty reliably 15 mins)
4) The "AP Ready" LED goes off - the "App Connected" LED goes on - Wifi drops - Goes from SSID list .. etc
Have to Power Cycle the unit.
Edit4: Actually - it just freezes after 15 minutes of no activity.
15 mins inactivity straight after power-on or 15 mins inactivity after an hour of use both resulted in the unit freezing.


Edit1: Sometimes (often) the Android App really really doesn't want to connect.
What often happens is the "App Connected" LED lights ON but the Android App freezes on startup or stays in Demo Mode despite repeatedly turning demo mode off.
The Windows App now won't connect as the unit thinks the existing Android App is connected.
Soon as I end the Android App the "App Connected" LED goes off and the windows app can connect fine.

Edit2: Found a way to have my Android App reliably connect.
1) Connect Android to a different AP - in that case my normal home wifi
2) Start Android App - defaults into Demo Mode
3) Go back into network settings and change wifi connection to the WFS210
4) Swap back to the App and turn off Demo Mode
Looks like shitty startup code in the App .... or maybe it's that my tablet is pretty rubbish - deliberately using a bottom of the range model to show up slow code I write :p
Edit3: Also works if I Turn Off Wifi - Start the App - Wait a bit - Turn On wifi - Back to App

Once connected I'm actually liking it for £20.
With some decent software (and a firmware fix for 15 min issue if confirmed) this could be damn good value.
« Last Edit: September 30, 2017, 10:08:35 pm by Avacee »
 

Offline R_G_B_

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #65 on: September 30, 2017, 09:05:25 pm »
So you pretty much screwed if you can not find an alternative AP to connect to first before trying out the method you have described.   

The software is sluggish when you  touch functions such AC DC GND you here the instant click of the relays but the display takes a bit longer to update.

By the way you method works
« Last Edit: September 30, 2017, 09:11:59 pm by R_G_B_ »
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Offline Avacee

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #66 on: September 30, 2017, 09:09:03 pm »
Sods Law on post timings :)

I was just editing that it also works if you Turn Off Wifi - Start the App - Wait a bit for it to initialise - Turn On Wifi.
 

Offline jimmc

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #67 on: September 30, 2017, 09:41:28 pm »
Connecting via USB on an old XP desktop(P4 2.8GHz)... works (but the display flickers a bit).
The 1 & 2uS/div settings are correct.
No wireless available.

Then spent a happy couple of hours resurrecting an old laptop (Athlon mobile 2.5GHz) eventually got software to load.
Totally unusable, 100% CPU, you can see the display scanning across the screen.

Re Android WiFi sequencing I had tried something similar, it worked most times but not 100%.

External power or battery only gave similar results.

I've had enough fun for one day, I will try your method tomorrow.

Jim


 

Offline Howardlong

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #68 on: October 01, 2017, 07:03:37 am »
Was the WFS210 an apprentice project that never got finished I wonder ?

Fraser

The thing is they clearly spent a significant sum on the aesthetics, with custom moldings etc, there were no shortcuts there in comparison to everything else. The software and firmware was definitely not given enough of the right resources in terms of development or testing.
 

Offline R_G_B_

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #69 on: October 01, 2017, 07:06:22 am »
Is this scope just a processor, front end and AD converter
That's sending everything to the tablet for processing.

I guess this may be one of the reasons  why it's very slow as it's having to do most of the processing on the tablet causing a lot of  lag


See Mike video 10 miniutes  in:

https://youtu.be/vO712DvGAKA


« Last Edit: October 01, 2017, 07:20:50 am by R_G_B_ »
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Offline Howardlong

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #70 on: October 01, 2017, 08:33:43 am »
This is with the battery and shields (both sides) removed.

Battery is an 1800mAh single cell LiPo, and amazingly the device still powered up after at least two years in the drawer.

If you take it apart like I just did (instructions here https://manuals.velleman.eu/article.php?id=576) be careful not to bust the on off switch or edge mounted LEDs like I did in step 4. You'll see I had to replace the push switch for a slide switch that I had in stock.

I get an error when on USB whenever I try to hook up a grounded source that there is a ground mismatch and I can't see anything on the scope. This is with the original firmware. I'm about to update it, which is why I took it apart, it wouldn't work with my iPad anymore, apparently there's a patch for IOS 10.

Original hi res images:

https://1drv.ms/i/s!Ak3HU3AygNouhOF9-CIhhXLk4doxPA
https://1drv.ms/i/s!Ak3HU3AygNouhOF8f44N9tBcXxEAkg




« Last Edit: October 01, 2017, 08:37:56 am by Howardlong »
 

Offline R_G_B_

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #71 on: October 01, 2017, 09:16:22 am »
They have a pin compatible version of the ADC

The MAX1193 is an ultra-low-power, dual, 8-bit,
45Msps

No way of accessing the firmware so that one could upgrade the ADC to 45meg samples per channel.
R_G_B
 

Offline Howardlong

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #72 on: October 01, 2017, 09:16:40 am »
I see from the docs that there is a feature that when running this device over USB, you can’t use it on a device with a common ground connection.  |O

Since upgrading the firmware I can’t get it to work on either a PC or IOS. Indeed, I can no longer find the app on the app store either.

At this point I think I was probably right to leave it in a drawer!
 

Offline Avacee

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #73 on: October 01, 2017, 09:23:00 am »
Is this scope just a processor, front end and AD converter
That's sending everything to the tablet for processing.

I guess this may be one of the reasons  why it's very slow as it's having to do most of the processing on the tablet causing a lot of  lag

Processing appears to be done on the unit.
Page 9/10 of the Protocol (https://www.velleman.eu/downloads/0/information/protocol_wfs210.pdf) doesn't send a sample value but screen position
Quote:
Sample buffer : Channel 1 & channel 2 samples (3 = top / 128 = center / 252 = bottom of screen)
For all timebase settings: 50 samples/div except for 1µs/div: 10 samples/div and for 2µs/div: 20 samples/div

When anything is changed the app sends the "settings" to the unit - Protocol Page 6.

The App simply draws the waveform, triggers, etc.
The app is hitting the CPU because it's trying to maintain a screen refresh rate of 60fps - even when it's not connected or no data has been received.
With a timebase of 1uS/div the unit averages 18 packets per second
With a timebase of 1S/div it averages 5 packets per second.
Edit: The USB does send the data much more frequently though - just tested it and it was sending 1938 packets/sec but of smaller length.

If you want to see the IP packets in Wireshark this is my filter:
(ip.dst == 169.254.1.1 ||  ip.src == 169.254.1.1) && !dns && !icmp && !arp && tcp.len > 0
« Last Edit: October 01, 2017, 09:35:20 am by Avacee »
 

Online FraserTopic starter

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Re: Velleman WFS210 wireless oscilloscope for only £20 !
« Reply #74 on: October 01, 2017, 10:31:38 am »
Regarding the hardware..... I think HowardLongs images show a pretty well designed and compact DSO unit.

It really is such a great pity that the software side of things is left so wanting.

I had s similar situation with a Wi-Fi spectrum analyser dongle from Ubiquiti. Their software was fully functional but there were enhancements promised that never happened. The Dongle was dropped from their product range without explanation. It turned out that the clever chap who designed the dongle and wrote the software had left the company. No one else could continue the development work in his absence. The product effectively became locked at its current build state with no further development possible.

I wonder if the programmer who wrote the WFS210 firmware and software has left Velleman ? I would have expected the bugs that we are finding to have been addressed quickly if he/she were still in the company.

Not much support visible on the Velleman forum either.

Fraser
« Last Edit: October 01, 2017, 10:33:56 am by Fraser »
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