Apparently, there is no need to connect, before attempting to flash a .hex file.............
So I tried simply flashing, to a paired micro:bit and after 30 seconds or so got the error:
"Flashing unsuccessful GATT ERROR". I tried several times with different .hex files. All produce the same result.
Can anyone help, please?
1 of 1 people found this helpful
And I have resolved it!
I was using the PXT editor which is more sophisticated than the simple Blocks Editor. At the time of making the original post, the default configuration of the PXT editor did not support Bluetooth connection, although the micro:bit would still pair, unless you explicitly loaded the Bluetooth package.
I have now been advised of a "workround" which ensures that you can ALWAYS pair and connect, irrespective of the contents of the current program installed on the micro:bit.
Please contact if you would like details.
This post edited 3 March 2017
This post edited again 07 November 2018 and UNMARKED as "Correct Answer"
Correct Answer now points to the Detailed Instructions on the pairing Workaround in a later post
I am trying to pair my microbit to my Samsung, but I'm not getting the pairing message on the microbit. I hold down the A and B buttons , then press the reset on the back for a second and let go. Absolutely nothing happens... could you send me details of the workaround you mentioned?
I just have the microbit connected to a Windows 10 machine, and I flash code successfully to it from Mu.
P.S. Is this what you meant by contact?
3 of 3 people found this helpful
Melissa - the problem you describe is one step further back from the problem I reported - you can't even put your micro:bit into pairing mode!
I have found the following to be the most reliable method of putting the micro:bit into pairing mode:
press and hold down the A and B buttons. Then press AND HOLD DOWN the reset button. Keep the reset button held down until the pairing message appears.
If this still doesn't work and you are powering the micro:bit connected from USB, try swapping to battery power, or vice-versa. In theory you can have both USB and battery connected at the same time, but I never do - just in case!
If you still can't get the pairing message it's possible that your micro:bit is faulty. Do you have access to anyone local to you who has a micro:bit? They might be able to help.
By the way, unless I am actually flashing the micro:bit, I run it on battery power - it seems to run cooler that way and I have already had 2 micro:bits fail because of overheating.
Hope this helps!
if you still need the workaround to achieve a connection, then contact again through this post thread - and yes this is what I meant by contact.
Hi, thanks for the reply
I have three microbits, and I've tried it with them all. Literally nothing happens ... I tried them with a battery pack, too, but now I will see if I can get some better quality batteries when I nip out for lunch... hopefully then!
2 of 2 people found this helpful
it's worrying that all 3 micro:bits are showing the same problem!
Have you, by any chance, flashed with a MicroPython script as mentioned by henrikbirkholm?
If so, then you need to reinstate the DFU code, as described here:
We would love to hear about your work around. How you get it to sync everytime.
After we transfered our first Python, the bluetooth sync functionality is gone. The pairing functionality was also gone until we made a block editor program and transfered it by cable. Even though the pairing now works again, we can't transfere programs by Bluetooth.
It seems like the block editor always includes the Bluetooth functionality, where as the python editor doesn't. Is it enough to import the radio module in a python program to the sync functionality back?
Please tell us your work around :-)
3 of 3 people found this helpful
Unforunately, installing a MicroPython script ALWAYS destroys the bluetooth pairing ability and the "workround" (courtesy of Joe Finney, Lancaster University) will NOT work with any MicroPython script, I'm afraid.
The "workround" is designed to allow flashing (Pairing/synchronising/bonding should work anyway!) with a PXT compliled .Hex file that does not have the Bluetooth module loaded. It shouldn't be necessary with a .Hex file compiled with any other Blocks style editor.
Here is Joe Finney's "workround", which will enable you to flash a .Hex file from the Samsung App:
- Flash micro:bit with a PXT compiled .HEX file that does not have Bluetooth enabled.
- Pair micro:bit with phone.
- Start Samsung micro:bit App
- Put micro:bit back into pairing mode.
- DO NOT try to CONNECT to micro:bit from Samsung App - it won't
- Go straight to FLASH from Samsung App - it should work!
I hope this helps.
Edited 07 November 2018 and marked as Correct Answer
Very clever - Neil. This worked for me - I was getting the "GATT ERROR" but following your workaround in exactly the given order enable me to upload some previous compiled code for driving a model car from an Andoid bluetooth app.
1 of 1 people found this helpful
Geez! Someone at embed - the people who wrote the firmware - must have a PhD from the Microsoft School of Obscurity - that has to be the absolute ugliest work-around I have ever seen! I cannot imagine a less obvious way to do something. . . .
I will have to try this myself though I give total respect and props to you for posting your detailed instructions - other postings allude to this but don't go into the detail you did.
Would you please change the "correct answer" designation to point at the posting where you provided Henrik with the detailed list of instructions? This should be what people look for when searching this article.
I also need to workaround. My micro:bit is paired to my phone, but none of the Blue Tooth apps can find my micro:bit. Thanks!
In your original post you said you could pair both of your devices to the microbit,
but are you pairing them separately or at the same time?
Thank you in advance.
To be perfectly honest, I can't remember, and it's been quite a while since I've worked with the micro:bit. However, I've just tried and I can pair to my android phone and to my android tablet at the same time.
Well what I mean is that I can pair the micro:bit to my phone and then go on and pair it to my tablet.
I don't know if this helps.
I've recently received my micro:bit and worked through most of the projects in jlucas 's blog - great start.
I'm keen to code on my Android tablet and smartphone and then use bluetooth to flash the .hex file to the micro:bit, but I'm not having any success.
I've downloaded the SAMSUNG app to both my phone and my tablet and after a lot of fiddling around, I can pair both devices to the micro:bit. I'm sure youngsters will get very very frustrated with this process!! I failed so many times to even start the pairing process that I found and downloaded a ble checker to both my phone and tablet - yes they both support ble - but not all phones/tablets do & that could be a problem for some users.
However, before I can flash the .hex file across, I have to connect to the micro:bit. Both the phone and the tablet repeatedly refuse to connect to the micro:bit, so I am stymied.