Pixl.js with Phyphox (connectivity issues with ios)

[LMB-UK]

I've recently purchased a puck.js v2.1, and updated firmware to 2v29. It connects fine to my laptop using the Espruino IDE and I can use the sensors/LEDs etc with basic commands. But I bought it to connect to the Phyphox app on my ipad or iphone. This should just directly work from what I understand. But although the app can see and connect to the puck, nothing happens when I try to start an experiment with sensors (no LEDs flashing, no measurements).
So I installed Bluefy and now using the Espruino IDE (Web version) it won't connect when I click the "connect" button: it sees the puck but when I select it I get:
Connection Failed: TypeError: JSON.stringify cannot serialize cyclic structures.
I'm a bit stuck on what to do. My coding abilities are pretty basic but hopefully somebody can help?
(For info: ipad details - ipad (7th gen) iPadOS vn 18.7.2
PhyPhox also has same issues on iPhone: iphone SE with iOS 26.5)
Thanks,
Linda

[gfwilliams]

I'm out of the office at the moment but will get back to you properly in 2 days when I return.

We don't have any relationship with Phyphox, in fact this is the first I have heard of them, so I'll have to look into how their app is supposed to work when I get back. If there is a way to contact them they may be more able to help though.

Have you seen this link? https://phyphox.org/wiki/index.php/Puck.js

Is your Phyphox app version definitely new enough?

On the iPad Web IDE front, someone recently posted up having some problems with Bluefy as well so I think there may have been some recent change in the Bluefy app that broke it. I believe Webble (around $2) still does work on the iPad though even if it doesn't look very polished - but presumably everything still works fine in the laptop if you do need the IDE?

[LMB-UK]

Hi there, Thanks for your quick response. The Bluefy info was really useful - I've tried the WebBle app and can now connect to the puck via the espruino IDE and activate LEDs and get a temperature reading so at least I now know I do have connectivity - I guess the issue must be with the code provided by the phyphox app (which obviously I don't expect you to know about). I've already emailed PhyPhox and looked at their wiki, but added a message here because I appeared to be unable to communicate at all between ios devices and puck - seemingly working now!
For info, PhyPhox is quite a cool app for taking all sorts of physics-related measurements, usually done on the actual device the app is on (e.g. phone) but using a puck would be better because you can do better experiments with that (by attaching the puck to moving objects etc, or moving it directly). With the cost of datalogging equipment to get similar experimental results being so high, the puck could be a great way for schools to save money and do things in a new way (I'm a secondary school Physics teacher in the UK so was very excited when I saw a post about this elsewhere).
Thanks again!

[gfwilliams]

I've had a quick look at the code we use to communicate via Web Bluetooth, and I spotted something that might have caused the JSON.stringify cannot serialize cyclic structures error with Bluefy and fixed it (the code was only in there for debugging anyway!). Maybe you could try the Web IDE with Bluefy again and see if it works? Make sure to hit refresh first so you get the new version!

I did try it with Bluefy on an iPad here, but mine's quite old now and seems to have issues with the IDE and uart.js examples (probably due to the un-updated safari), but the Puck.js ones work fine (https://espruino.github.io/EspruinoWebTools/examples/puck.html)

PhyPhox looks really cool - I tried it here on my old iPad and it's the same as yours: the Puck.js will connect but the screens don't appear to work. However I tried it on my Android phone and it worked first time - I connected to the Puck, chose an experiment type, pressed the Play button and it worked right away! So if your school has any Android tablets or even Chromebooks (which can run Android apps now) I imagine they'll work perfectly.

If Phyphox do get back to you it might be worth telling them it seems to be an iPad-specific thing as that might help them track it down.

We're UK-based too and I'm always happy to try and support schools, so if there's a way you think we might be able to help let me know - for example I could easily make a website that graphed sensor data like Phyphox appears to.

We also have other products that potentially have some great possibilities for data logging. Bangle.js can record and stream acceleration, heart rate and so on, or Jolt.js has screw terminals so could be very useful for recording data from experiments without needing any soldering.