Velleman WFS210 wireless oscilloscope for only £20 !

[jimmc]

I've been using a variant of Avacee's method...

1  With WFS210 off turn on Tablet
2  Start App select 'Settings' and untick 'Demo Mode'
3  Turn on WFS210 and allow to settle
4  Connect Tablet WiFi to WFS210
5  Back to App 'Settings' screen
6  Back again to App 'Main' screen and it should connect.

If I understand correctly, the common point seems to be to connect to the WFS210 WiFi while the App is in the 'Settings' screen.


I am really torn, the hardware seems good, the Android App appears to be almost there but maybe could be good with a little work.
On the other hand the Windows software is useless and in need of a complete rewrite. (I  haven't got any Apple devices to try.)

For £20 I'm tempted to keep it and hope the someone with more knowledge than me can fix the App.
One thing worries me, if the last firmware update (1443) is dated 24/10/2014, how old are the units with the older version(1423)?

Can somebody confirm the 5, 2 , 1uS problem on the Android App. (Windows version works correctly)

Jim

Fraser, I've just seen your post I think you could very well be right.

[Howardlong]

One comment regarding the board layout is that the vias are too close to the passives, so there is not enough room for solder mask between the via and the pad. This makes the parts look “wobbly” as the solder paste will drag the part towards the via.

I can imagine there being a lot of tombstoning during production because of this. Another option is to cover the vias with solder mask and only expose the pads in the mask layer.

[Avacee]

Can somebody confirm the 5, 2 , 1uS problem on the Android App. (Windows version works correctly)

I confirm that I get the same on the Android App. Doesn't matter on the input frequency it shows the same image for 1, 2, and 5us.

Does your unit freeze after 15 mins of inactivity?

[jimmc]

Hi Avacee,
I can confirm the 15min freeze as you describe, it also happens if you just turn the unit on and leave it without ever connecting.
It does seem pretty accurately 15min, could this be a battery saving feature?
As has been mentioned Wireless can be power hungry.

One other thing, on my unit the BNC earths are at + 1.62v relative to the USB earth. S/C current is 11.3mA

Jim

[janoc]

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

Well, Velleman has never been known for high quality products - apart from their kits, most of the stuff they are selling are just rebrands of various devices sourced in China. If the original hardware has crappy software/firmware, you are pretty much stuck with it.

They are also well known for their unwillingness to open/document the protocols of most things they sell.

[Avacee]

Hi Avacee,
I can confirm the 15min freeze as you describe, it also happens if you just turn the unit on and leave it without ever connecting.
It does seem pretty accurately 15min, could this be a battery saving feature?
As has been mentioned Wireless can be power hungry.

One other thing, on my unit the BNC earths are at + 1.62v relative to the USB earth. S/C current is 11.3mA

Jim

Think you are right regarding battery saving ... After 35 mins with a powerpack it hadn't frozen .. 15 mins after unplugging it it froze.
Plugging it back into the power pack or into the PC didn't resurrect it ... Firmware Fail :p

I also get the 1.6V.

[Fraser]

I have raised a message on the Velleman support forum.

https://forum.vellemanprojects.eu/t/wfs210-tested-and-this-product-has-issues-request-for-support-comment/27511

Fraser

[Fraser]

This may be the WFS210 App developer at Velleman:

https://github.com/velbn

https://github.com/Velleman/WFS210-App

It looks like he is still working on it, at least 8 months ago, so there may be hope ?

Fraser

[R_G_B_]

Fraser,

maybe you could  ask them if they have abandoned the hardware could they release the firmware

They have in the past realeased schematics for the HPS,140i

The thing that's very wrong in all this is they continued to sell a product at around £100 that they knew had problems and did not function accordingly.

I wonder how many got their money back?

Velleman should step up to the plate on this I'm perplexed as to how they managed to continue selling this knowing what they did

[Mr. Scram]

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

Having a product stall out due to someone leaving the company signifies serious management issues. If your standards are up to snuff, including documentation and common standards, someone else should be able to pick up a project with at worst moderate effort.

[trevwhite]

I received one today and plugged it into my Windows 10 machine via USB and the thing works nicely. Couple of things.

Software is basic but I just measured a 10Khz pulse from a switch mode power supply no problem
If you unplug the usb whilst the software is loaded and plug it back in again it has troubles. You have to close the application and start again.

I have not tried any wifi stuff yet, seems that is a can of worms at this stage. But so far for £20 if it does that basic stuff then great. Would be good if it had a logger function to it.

Trev

[R_G_B_]

What version firmware are you running?

I tried windows 10 no luck it keeps locking and I get the error code

Writefile function failed error 121

[trevwhite]

Everything is stock straight out of the box.

Windows software is WFS210 v1.3.0.0

It does start locking up a bit. I find I have to click again the timebase setting and it sorts itself out. I also changed the top right voltage parameter and that really screwed with it. I am running it through a Dynadock usb hub which connects to my pc via a USB 3.0. I think its so close to being usable.

[R_G_B_]

It seems to be running ok now.

It also seems to work ok on windows 10 over wifi


Has it moments but been running it for 20 miniutes stable for now

Ok I guess up to 1 MHz

[R_G_B_]

Had it working very well on android now it' won't connect

Head ache 

[Fraser]

This is the behaviour that baffles me..... it works one day, but not the next. Weird and indicative of an unstable firmware build me thinks. Every time it boots, it is Russian Roulette as to whether it will link with the Android host easily or not.

I am suspicious that the Android APP sends a 'hello, are you there?' Message to the WFS210. If it gets no response, it goes into demo mode. Multiple 'hello, are you there?' Requests might eventually elicit a response and so the link is created.

Fraser

[Fraser]

I suppose the confirmation of the issue would be to create a 'hello, are you there?' (Whatever that may be) message for the WFS210 and then see how often it responds. Monitoring the Wi-Fi data might provide such information but that is not something I can do.

Fraser

[Avacee]

I downloaded the current Github and ran the Android App on my tablet under the debugger.

The App connects using the standard libraries - this doesn't always work - in fact it seems to always fail the first time and this puts it into demo mode.
I've tried varying the connection attempt timeout (default 2s) but no luck.

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 

When it goes into what we experience as the "Demo Mode Untick cycle" I have some suspicions on what I think is happening and am trying a few things to improve that initial connection chance.
Alas those pesky beer voucher providing clients have got in the way today.

[Avacee]

Regarding the 1,2,5 us issue.

I've stepped through the code and the Settings packet is being sent to the unit with the correct byte value set.
However it works on Windows so must be something else... still bashing my head against this one

[Fraser]

Avacee
Great investigative work 

I was only kidding when I said I expected a Hello, are you there? Challenge. I did not expect *Hello* to be the real handshake 

Fraser

[Fraser]

Nothing from a Velleman today. I need to be patient though 

Fraser

[Mr. Scram]

Nothing from a Velleman today. I need to be patient though 

Fraser

I wouldn't expect a quick reply, considering the rest of the support hasn't been quite furious either.

[Fraser]

No, that is what I fear. That will, in itself, speak volumes though. An abandoned product line with problems still being sold for significant money...... not great PR for Velleman me thinks.

Fraser

[Avacee]

Found the Android 1,2,5 us bug.

As detailed in the protocol: For all timebase settings: 50 samples/div except for 1µs/div: 10 samples/div and for 2µs/div: 20 samples/div)

The SamplesPerTimebase is calculated once in OnSizeChanged() which is called during the initial layout.
The default TimeBase when the apps starts is 1ms so it's set at 50 samples.
It's never ever calculated again   so when it maps the SampleDataToScreen for 1us and 2us it uses the wrong value.
Edit: Unless you change your screen size which is unlikely :p

Recalculating the ratios for 1us and 2us results in a correctly updating display. 

[Specmaster]

Found the Android 1,2,5 us bug.

As detailed in the protocol: For all timebase settings: 50 samples/div except for 1µs/div: 10 samples/div and for 2µs/div: 20 samples/div)

The SamplesPerTimebase is calculated once in OnSizeChanged() which is called during the initial layout.
The default TimeBase when the apps starts is 1ms so it's set at 50 samples.
It's never ever calculated again   so when it maps the SampleDataToScreen for 1us and 2us it uses the wrong value.
Edit: Unless you change your screen size which is unlikely :p

Recalculating the ratios for 1us and 2us results in a correctly updating display. 

Is there any way the app can updated with all the little gems that you're uncovering and correcting, and then made available for downloading to update our versions as well?