micro:bit cannot connect to Chrome microBlocks

[Robert Ralston]

Two old boards had 0234 firmware from 2015. Both updated to 0253 (later 0249).

Both boards can be programmed from MakeCode but neither board will connect for microBlocks. Same with two different cables and two different USB hubs.

iMac 10.14.6, Chrome Version 85.0.4183.83 (Official Build) (64-bit); Chrome flags enabled: Experimental Web Platform features and Enable Portals

When trying to connect from microBlocks, behavior of the USB connect button is weird; there is a dropdown box saying BBC micro:bit CMSIS-DAP (cu.usbmodem 1423402) - Paired. Selecting that line then activates the Connect button. But nothing happens. The USB icon never gets a green dot behind it but a new little icon does appear in the tab just left of the X which explains itself as “this tab is connected to a serial port”

When I again click on the USB icon in the microBlocks menu, the dialog box is disconnected from that icon and sort of floating off to the right.

When I put the set user LED block in the programming area, and click on its button, a green dot does temporarily appear behind the USB icon, but then disappears.

When I click the green Run triangle, there is a very brief flashing of a green dot, over and over, behind the USB icon.

Since I had other USB devices attached (Saleae logic, StemTerra board, couple more) everything got unplugged and a iMac restart. But same problem.

Both external USB ports are powered (cirago and USBgear). These USB hub ports do work with Arduino programming, Saleae logic probe, WebFPGA (which also uses WebUSB), and Microchip’s IPE running from an up-to-date Windows10 install under an up-to-date Paralles.

I don't know what else to try. I put “minor” as the bug since I’m not a developer but just a hobbyist.

Thanks for any guidance you can offer.

[Robert Ralston]

Today I tried using the web interface on a different machine, AirBook, all current software, nothing else attached.

Same behavior as described above. Clicking the Run triangle starts a continuous very brief flashing of what appears to be a green dot behind the USB icon.

The flashing corresponds with a quick flash from the LED on the micro:bit next to the reset switch, as if they are trying to communicate but cannot.

The board does work with the standalone microBlocks app on both machines

[John Maloney]

Sorry you’re having problems – and thanks for reporting them. We definitely want the browser version to work well with the micro:bit.

Have you installed the MicroBlocks firmware on the board? To do that, plug in the board and make sure it appears as a USB disk drive. Then start MicroBlocks in Chrome, but don’t connect yet. Select “update firmware on board” from the MicroBlocks (gear) menu and follow the prompts. Firmware installation takes about ten seconds, during which you’ll see the orange LED next to the reset button flashing. On a Mac, you’ll also see a message about the USB drive being disconnected while the micro:bit installs the firmware. That’s normal. A few seconds after that you should be able to connect to the micro:bit. The connection indicator should stay green and you should be able to click on blocks to run them.

You’ll need to re-install the MicroBlocks firmware after using MakeCode on the board since MakeCode replaces the MicroBlocks firmware with it’s own (and vice versa). Fortunately, the firmware install process is quick.

Let me know if this solves the problem for you. Thanks!

[Robert Ralston]

John, thank you for your message.

First I updated the micro:bit to its latest firmware, 0253.

Then I connected in the standalone app and got a message that I needed to update from something like 0.9 to 0.91 (sorry did not write down the exact info).

As before, I could connect using standalone app.

But not it also works with the web app, so seems like problem solved. It seems to consistently connect, disconnect, and run using the green triangle. Thank you.

[John Maloney]

Glad you got it working! What was the key step? It sound like you had already updated the micro:bit’s firmware to 0253 when you posted the bug report, right? So it sounds like the key step was to update the MicroBlocks firmware (different firmware from the micro:bit firmware) on the board using the standalone app.

MicroBlocks could/should suggest updating the firmware that when the web app can’t communicate with the board the user selects. I hadn’t thought of that, so thanks for reporting this problem!