Engines/Motors with and without the LEGO logo; the latter works with Spike Prime, but not with PyBricks

[tomaszsiwak]

Today I tried a simple program on the Technic hub with Lego Spike Prime motors. I have the original motors and a dozen or so purchased on AliExpress (without the LEGO logo, but they work perfectly in Spike Prime). When I connect the ones without the logo in Pybricks, I get a hangup next to: a = Motor(Port.A) or a message that there's no motor connected to Port A at all. Is there a way to fix this? It would be great if they worked here too.

[dlech]

We've had other folks do the same thing: #2305

If someone wants to do some reverse engineering and finds that there is a trivial way to support them, we would consider it. But personally, I'm not keen on supporting knock-off products.

[tomaszsiwak]

Okay. I understand. Just for information: I also tested this with a small Spike Essential hub and a large Spike Prime: Same result.

[laurensvalk]

Could you please try these instructions to help us gather a bit more information about these devices? This may help us fix it. Thank you.

[dlech]

The hub name is limited to 15 characters. We made it this small so that it fits in the BLE advertising data.

[tomaszsiwak]

Ah, good to know. ;-) Red frame, but absent-minded people like me still can click Next... Ehh

[dlech]

In the data we can see that the motors stop responding after we try to switch to mode 4, which is the CALIB mode. This mode isn't used by the official LEGO apps (other than to calibrate the motors that came with the Robot Inventor set). So it is likely that the mode isn't implemented in 3rd-party motors.

Laurens will remember better than me, but IIRC, we used this mode rather than APOS to get better resolution of the position. So if there is something else in the data that is different than the official LEGO motors that we could use to detect the difference between the two motors, we could possibly make it work by selecting a different mode.

[russm1981]

Hi

I am interested in this discussion and whether there is a fix for the third party motors either now, or coming if I am patient? I don't mind buying some LEGO motors but they're unreasonably expensive for what they are.

Like the original poster, my AliExpress ones work with LegoApp but not PyBricks. Adding one in the setup section hangs the programme.

I am also having problems with all the sensors I have too - none of which seem to work on PyBricks and again hang the program at setup (Joystick, variable resistor input, IR sensor input). Again, is there a fix or workaround for this?

Again, I don't mind buying some official sensors but where do I source them? They don't seem to be available anywhere (Lego has retired them all?). Will MindStorm sensors work if I buy those? I am completely confused by all the different connector types over the different Lego systems.

Thanks

Russ

[dlech]

If it has the Powered Up connector (and is genuine LEGO product), it will work with Pybricks. There are several LEGO brick marketplaces like https://bricklink.com and https://www.brickowl.com/ where you can find new and used parts.

The sensors sound like 3rd-party sensors (not clones of anything LEGO made). So it would be useful to see some links to docs on those and we might be able to give some hints on how to use the PUPDevice class on how to use those.

[russm1981]

David Really appreciate the reply. Here they are: https://www.aliexpress.com/item/1005006913609638.html?spm=a2g0o.order_list.order_list_main.26.38041802J2PL05 Remote sensor (joystick), potentiometer and distance sensor (looks like Lego IR) Any tips on how I’d go about modifying the class to support any protocol modifications required would be appreciated

[dlech]

I didn't see any technical documentation there. So you would just have to play around with it.

You should be able to do something like:

sensor = PUPDevice(Port.A)

print(sensor.info())

This will print out the available modes, etc. Then you can try to play around with reading data from the various modes until you find one that works.

[russm1981]

David, For the Joystick I get: {'id': 34, 'modes': (('LPF2-ANGLE', 2, 0), ('LPF2-TILT', 1, 0), ('LPF2-CRASH', 3, 0), ('LPF2-CAL', 3, 0))} For the IR/distance sensor I get: {'id': 35, 'modes': (('LPF2-DETECT', 1, 0), ('LPF2-COUNT', 1, 2), ('LPF2-CAL', 3, 1))} For the potentiometer I get an error when using the PUPDevice command: Traceback (most recent call last): File "<stdin>", line 1, in <module> OSError: [Errno 19] ENODEV: A sensor or motor is not connected to the specified port:

…

--> Check the cables to each motor and sensor.

--> Check the port settings in your script.

--> Check the line in your script that matches the line number given in the 'Traceback' above. Thank you! Russ From: David Lechner ***@***.***> Sent: 26 October 2025 21:41 To: pybricks/support ***@***.***> Cc: russm1981 ***@***.***>; Comment ***@***.***> Subject: Re: [pybricks/support] Engines/Motors with and without the LEGO logo; the latter works with Spike Prime, but not with PyBricks (Discussion #2347) I didn't see any technical documentation there. So you would just have to play around with it. You should be able to do something like: sensor = PUPDevice(Port.A) print(sensor.info()) This will print out the available modes, etc. Then you can try to play around with reading data from the various modes until you find one that works. — Reply to this email directly, view it on GitHub <#2347 (reply in thread)> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/BCWDYYXUS3KVSI3SUR5T23L3ZU5W7AVCNFSM6AAAAACGBQ5556VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTINZYG4ZTANQ> . You are receiving this because you commented. <https://github.com/notifications/beacon/BCWDYYTD6NHWIBCFATZW5Q33ZU5W7A5CNFSM6AAAAACGBQ5556WGG33NNVSW45C7OR4XAZNRIRUXGY3VONZWS33OINXW23LFNZ2KUY3PNVWWK3TUL5UWJTQA4GROU.gif> Message ID: ***@***.*** ***@***.***> >

[dlech]

The next step is to try a mode and see what kind data you get. The first mode being the most likely one to work.

I.e. extend the program with:

ANGLE_MODE = 0
TILT_MODE = 1

while True:
    print(sensor.read(ANGLE_MODE))
    wait(500)

Not sure what we could do about the one that gives ENODEV. You could try this if you want to spend time debugging it.