Flea-Scope™ USB Oscilloscope, Logic Analyzer, and more ($18, 18 Msps, WebUSB)

[theoldwizard1]

It appear that I have the same "Failed to execute 'claimInterface' on 'USBDevice' : Unable to claim interface" that shabaz has but on a Amazon Fire Max 11 running Chrome.  I suspect it is the same problem as you mentioned ("the platform binds a serial driver to the device").

Would his work around solve this problem on the Max 11 ?

[rich t]

The first thing to try is the "manual" flavor of the web-page...

The automatic web-page (which decides on using WebUSB or Web Serial based on the navigator.userAgent) only works for the platforms I have tested on.

So start by opening this: https://rtestardi.github.io/usbte/flea-scope.manual.html

And then try "Start Connect Comm" and "Start Connect USB" one at a time.

If neither of them work, then it is possible you are hitting this issue: https://github.com/rtestardi/usbte/issues/5

The solution to that is to force your Flea-Scope to expose a non-CDC/ACM endpoint, so the serial driver will not attach to it.

You have to start with a firmware upgrade (instructions in user's guide and you need v2.27j):

https://rtestardi.github.io/usbte/flea-scope.pdf
https://github.com/rtestardi/StickOS2/blob/main/board/pic32.X.27j.0x39ca.production.hex

Then you need to ground pin a0 on boot -- this will tell Flea-Scope to expose a non-CDC/ACM endpoint.

Then the serial driver won't attach to it so you have to always use "Start Connect USB" on the manual flavor web-page:

https://rtestardi.github.io/usbte/flea-scope.manual.html
https://rtestardi.github.io/usbte/stickos-basic.manual.html

It is unfortunate that some platforms have serial drivers but do not expose Web Serial into the browser -- the only one I knew of before was Samsung.

Possibly Fire is a second.

Sorry for the trouble.

[RAPo]

I've ordered a second flea-scope, This time with an USB-mini->USB-C cable. Connecting it to my phones (I have two Androids) doesn't deliver any power to the flea-scope.
A desktop PC works well.
Is there any reason it is not working on my phones?

[rich t]

I have never had an experience where the phone does not deliver power -- is your phone capable of powering and connecting to USB devices, or might the USB port be only for charging the phone?  Flea-Scope is a USB 1.1 device operating at 12 Mbit/sec (aka full speed).  One guy could not get the phone to connect until he switched to a real data cable -- many cables nowadays are power-only.  But as long as you get a cable rated for data (which has more wires, typically 4), it should work -- there is nothing special about the cable from elecrow (well, except I have tested with it :-).

[RAPo]

I also tried the neighbour's phone. I'm still having no luck. The cable seems all right (see the attached photo).
Tested phone brands:

• Huawei P smart Z
  Huawei P30 Lite
  Ulefone Note 18 Ultra
  Moto G62 5G
  

and a Lenovo Duet Chromebook.

All devices can synchronize data with a standard data cable.

I have never had an experience where the phone does not deliver power -- is your phone capable of powering and connecting to USB devices, or might the USB port be only for charging the phone?  Flea-Scope is a USB 1.1 device operating at 12 Mbit/sec (aka full speed).  One guy could not get the phone to connect until he switched to a real data cable -- many cables nowadays are power-only.  But as long as you get a cable rated for data (which has more wires, typically 4), it should work -- there is nothing special about the cable from elecrow (well, except I have tested with it :-).

[PlainName]

They probably need an OTG cable, which isn't a normal one. There is an additional pin with resistor, which is missing in your photo (ID).

I had the same issue: phone didn't work with a normal cable plus A adapter. But an OTG splitter (two A socckets, one for external power unused for this experiment) did work fine.

[RAPo]

Many thanks—that did the trick, even without a USB splitter. I had an old OTG cable lying around, and it connected with power on the first try at each of the above-mentioned devices.
So should the elecrow cable be an OTG or do I have a bad specimen?

They probably need an OTG cable, which isn't a normal one. There is an additional pin with resistor, which is missing in your photo (ID).

I had the same issue: phone didn't work with a normal cable plus A adapter. But an OTG splitter (two A socckets, one for external power unused for this experiment) did work fine.

[PlainName]

So should the elecrow cable be an OTG or do I have a bad specimen?

Depends if it's being sold for use with a PC or phone. Personally I'd expect an A to micro-B to be normal data, and C to micro-B to be OTG (why else would you want a C at the host end). But I'm not involved in any way, so... 

[RAPo]

It was sold as an add-on to the flea-scope ;-)

So should the elecrow cable be an OTG or do I have a bad specimen?

Depends if it's being sold for use with a PC or phone. Personally I'd expect an A to micro-B to be normal data, and C to micro-B to be OTG (why else would you want a C at the host end). But I'm not involved in any way, so...