My browser / operating system: Windows NT 10.0, Chrome 64.0.3282.140, No Flash version detected

I've just come here by elder's recommendation. I had multiple posting sorry.
Connecting to the Physical World » micro:bit is not connecting to Scratch. (Slightly advanced)
Developing Scratch Extensions >> Problem with BBC Micro:bit extension : Bluetooth not connecting.

I spent a few weeks effort to solve this but I've never succeeded to establish BLE scratch-link connection to Scratch3.0. I saw following message many times, but both I did.
1. Make sure you have Scratch Link installed and running
2. Check that Bluetooth is enabled

Windows10 Pro
10.0.17134
Intel(R) Wireless Bluetooth (BLE)
I tried another Win10 desktop with BLE dongle, and failed.

Scratch
Scratch 3.0
https://scratch.mit.edu/projects/editor

Browsers
Microsoft EdgeHTML 17.17134
Chrome Version 74.0.3729.169 (Official Build) (64-bit) No Flash version

Scratch-link
1.1.85.0 from Github
1.1.46.0 from official, both failed

Micro:bit
scratch-microbit-1.1.0.hex installed
Daplink Interface Version: 0250


I still have big motivation to enable this feature because it is much fun for me and my children.
Some questions for continuing to debug. Please help me.

+ How to narrow which has issue BLE or Scratch-link?
+ Which is correct Micro:bit is paired or not?
+ Scratch-link should be launched as admin?
+ Any security config of Windows 10 needed?
+ What is correct launching sequence? 1-2-3-4? or any?
1. Micro:bit power on
2. Scratch-link starting
3. Micro:bit pairing
4. Scratch3.0 starting
+ Anyone tried with more than one Micro:bit's ? I have only one. Should I buy more?

Thank you.

I found a clue by myself !!! It depends on “place” !!! I succeeded to link my Micro:bit at ANOTHER “place”.

Using same Scratch3.0 + PC(without reboot) + Micro:bit + Scratch-link, only difference is to change the “place”.

Issue “place” immediately pop-up following dialog, any condition of Scratch-link and Micro:bit
(Error dialog) 1. Make sure you have Scratch Link installed and running
2. Check that Bluetooth is enabled

Good “place” withOUT Scratch-link running
(Looking for dialog) Looking for devices
after 1 second
(Error dialog) 1. Make sure you have Scratch Link installed and running
2. Check that Bluetooth is enabled

Good “place” WITH Scratch-link running , withOUT Micro:bit power
(Looking for dialog) Looking for devices
after 15 seconds
(No device dialog) No devices found

Good “place” WITH Scratch-link running , WITH Micro:bit power
(Looking for dialog) Looking for devices
after 0-4 seconds
(Select device dialog) Device name BBC micro:bit …
Select your device in the list above


Does someone know any reason? or what I should try? Please help.

since you find a good place to work, why not stick to it?

some assumptions for your reference only :

physical layer there could be some band sharing from WIFI to BLE adv channel, so if some place is too much bothered by WIFI signal, it might affect BLE discovery. or might be the bad place is just a dead corner of BLE signal?

I used to have quite good stable connections, very worst case if lost my microbit after opening too much chrome pages or some unknown freezing issue in Windows 10 then I will do reset my bit and my pc (control panel-bluetooth-enable to disable then to enable). then I can recover the ble connection easily.

hope it helps

alberthink wrote:

since you find a good place to work, why not stick to it?

some assumptions for your reference only :

physical layer there could be some band sharing from WIFI to BLE adv channel, so if some place is too much bothered by WIFI signal, it might affect BLE discovery. or might be the bad place is just a dead corner of BLE signal?

I used to have quite good stable connections, very worst case if lost my microbit after opening too much chrome pages or some unknown freezing issue in Windows 10 then I will do reset my bit and my pc (control panel-bluetooth-enable to disable then to enable). then I can recover the ble connection easily.

hope it helps

Thank you alberthink, your comment will keep my motivations.
My goal is to use them in my home :-)

My Micro:bit was located nearest from PC. And Micro:bit was successfully paired with PC. It seems not to relate physical radio-wave condition.

>I will do reset my bit and my pc (control panel-bluetooth-enable to disable then to enable)
I did multiple times in control panel, but still unconnected.

It is much strange, but may be strongly depended on other un-connected Bluetooth devices around the “place” ??
After I go back home, that is “Issued place”, I'm going to try powering off Bluetooth devices in my home sequentially.

I will report again as soon as any update or finding the “BLE connection blocker”.
Thank you.

Bad report. I could not find any “blocker” at last night.

I disabled Wifi of PC. The situation was same.
I turned off all Bluetooth devices in my home. But a couple of devices outside of my home still exist …. someone's Samsung TV and HP printer.

Update.
I've found the Micro:bit BLE connection issue is just depended to use “Router” or not.
It is mysterious.

Good cases
Using “Wifi” Cell-phone tether for Scratch3.0 web connection.

Issue cases
Using “Wifi” DDRWT router for Scratch3.0 web connection.
Using “Wired” DDRWT router for Scratch3.0 web connection, and “Wifi” disabled on PC.
No internet but Scratch3.0 web page is cached. Push reload button.

Conclusion? but not solved.
Scratch3.0 & Scratch-link initiates special internet communication and it is blocked by my DDWRT router.

Please help !!!

SOLVED !! FINAL REPORT - for everyone has same issue

Issue: Scratch3.0 with Scratch-link cannot establish BLE connection to Micro:bit on a specific local network place

• Condition1: tried out all known setup procedures
  
• Condition2: success pairing Windows10 and Micro:bit without Scratch-link.
  
• Condition3: you have never seen “No devices found” dialog 15 seconds after “Looking for devices”
  
• Condition4: multiple devices (PC, Micro:bit) on same local network have same this issue
  

Please notice following action will have more security risk.

Solution1 - modify hosts file on your PC

• Open C:\Windows\System32\Drivers\etc\hosts as administrator
  
• Add following extra line:
  

  127.0.0.1 device-manager.scratch.mit.edu

Solution2 - not to use local DNS on your PC

• Add public DNS (ex. google-public-dns-a.google.com) in priority to your PC's original DNS configuration
  

Solution3 - change local router configuration

• Request your local IT admin, to change DNS to permit “device-manager.scratch.mit.edu” to be 127.0.0.1, or
  
• Disable your router config “No DNS Rebind”, or
  
• Disable your router config “DNS Masquerade”
  

Reason

• Scratch-link initially looks for device-manager.scratch.mit.edu via internet connection
  
• Local router blocks solving ip address of “device-manager.scratch.mit.edu”
  

  C:\Users\y05s>nslookup device-manager.scratch.mit.edu google-public-dns-a.google.com
  Server: google-public-dns-a.google.com
  Address: 8.8.8.8
  
  Non-authoritative answer:
  Name: device-manager.scratch.mit.edu
  Address: 127.0.0.1
  
  C:\Users\y05s>nslookup device-manager.scratch.mit.edu
  Server: DD-WRT
  Address: 192.168.1.1
  
  *** No internal type for both IPv4 and IPv6 Addresses (A+AAAA) records available for device-manager.scratch.mit.edu
  

• Scratch3.0 cannot proceed to start looking for Micro:bit via Bluetooth
  

So, my admin did the first step, but the micro:bit still couldn't connect. What do you think I should do? Maybe I have to do all of the following actions, including solution 2 and solution 3?

Please I need help! I have a laptop with Windows 10 version 18909 and I want to connect Scratch Desktop 3.0 with Wedo 2.0.
I already have the Scratch Link installed and running but it doesn't detect the WeDo Hub.
However, the official Wedo 2.0 software communicates correctly so you can rule out a problem with bluetooth.
Please … I need some help!
Grateful in advance.
Greetingssss

… And without internet connection

Sorry I was away from Scratch for a long time. I may help you If you still have issue.
But I don't have Wedo since it was expensive. The idea of editing “hosts” works without internet connection.

My browser / operating system: Windows NT 10.0, Chrome 81.0.4044.129, No Flash version detected

would this work for microbit?

I got the same problem where scratch can not find the micro:bit.
The root cause of the problem is Chrome (or the new Microsoft Edge) failed to connect to the Micro:bit because of this error:


WebSocket connection to ‘wss://device-manager.scratch.mit.edu:20110/scratch/ble’ failed: Error in connection establishment: net::ERR_SSL_OBSOLETE_VERSION


The solution is to allow chrome to connect to legacy SSL. With following procedure:

In your browser address bar, type:
chrome://flags/#legacy-tls-enforced

select ‘disabled’

restart your browser.

@cwkjustin46125 - Allowing chrome to connect to legacy SSL did the trick. Thanks a ton !!!

Wow!!! I remember: “Scratch is very simple”.

Still having problems? I can get it connected.

Detailed explanation:

• Install Scratch Link: https://apps.microsoft.com/store/detail/scratch-link/9N48XLLCZH0X?hl=en-us&gl=us
  
  

• Plug the micro:bit into the USB port with a Micro-USB plug, and install the hex file from the help page: https://scratch.mit.edu/microbit
  
  

• Unzip the hex file: https://www.zipfilesonline.net/unzip
  
  

• In file explorer, locate the hex file, and drag and drop it onto your micro:bit.
  
  

• Enable bluetooth in your devices settings.
  

• Press the icon represented by the blocks with the plus, and add the micro:bit extension.
  
  
  

• Wait a few moments, and select the micro:bit from the list.
  
  

• Wait for it to connect, then press the ‘Go to Editor’ button. Get creating!
  
  

Troubleshooting:

• If you see this pop-up, double check that bluetooth is enabled, or search Scratch Link using the magnifying glass on your Windows taskbar, search Scratch Link and press Open.
  

—————————————————————————————————————————————————————–

• If your device is not appearing, and you followed the above steps, ensure that the micro:bit is receiving power, either through a USB cable or a battery pack.
  

• If you are using a battery pack, ensure that the batteries are the right batteries, make sure not to mix different types of battery (e.g. rechargeable and alkaline, fresh and old, etc.) ensure that the negative (-) side of the battery is touching the spring and make sure that the batteries aren't dead.
  

Happy Scratching this Halloween!