Hi! I recently purchased a nice gadget from AliExpress, this should be the circuit to drive an ultrasonic piezo. Silly me, I put the batteries backwards and the U1 component on the bottom left blew up.

I know a bit about circuits so I reverse engineered it (there might be mistakes), but I am not skilled enough to identify the component in order to look for a replacement. Can someone help me identify it? I can read ___22 on it.

Here's another version of the schematic, which might be easier to understand.

Thank you for your help!

EDIT: I couldn't identify the component, but I did a Google Image Search as suggested by @partial_accumen@lemmy.world and it found similar PCB designs. It very much looks like this component is part of the charging circuit, which I do not particularly care about. I will try desoldering it and see if the rest of the device still works. I will post the outcome here.

EDIT 2: with a lot of help from @jeinzi@discuss.tchncs.de I managed to fully reverse engineer it and fix most of the mistakes in the schematic. That component was just an FP6291 after all, part of a circuit to step up the 3V from two AA batteries to 5V required by the MCU. I replaced that whole section with a step up module I had previously purchased from AliExpress, and now everything works again.

Here's the final (mostly accurate, hopefully) revision of the schematic.

(link)

Lessons learned:

• Always double-check battery polarity
• In the age of AI, Google Image Search can now help identity circuits
• Sometimes a circuit that looks complex can actually be much simpler in the end
• AskElectronics@discuss.tchncs.de amazing community on Lemmy

That was fun! Thank you very much to everyone who contributed to this thread!

Today Plasma 6.6 was released. Among the new features, they updated KDE's virtual keyboard (link), and I would like to give it a try.

By default Bazzite uses Steam's virtual keyboard. I remember I could see KDE's OSK (On-Screen Keyboard) icon, but I never managed to launch it from Bazzite, it just didn't open when clicked. Now I can't even find the icon anymore. Also, I could never find any references to it online.

Is it even possible to do it, or has it been "chiseled away" from the system? Opening KDE's keyboard in desktop mode would be enough for me; enabling it in game mode would be secondary.

If you know if it is supported in Bazzite and/or how to open it, please share your wisdom. Thanks!

I decided to write down a list of complete (no alpha/beta), playable (no proprietary dependencies), FOSS videogames.

I added all the games I could find online + all of the games that came to my memory.

Feel free to have a look to see if there's something you didn't know. And please suggest anything I missed, but please do not suggest pre-release or unfinished games.

Thank you!

EDIT: thank you very much everyone for the comments and for sharing additional awesome lists of FOSS material. Hopefully one day I will have the time to sift through all these games and pick all the non-pre-release ones which don't have any proprietary dependencies.

In the meantime, here's a copy of the links:

• LibreGameWiki - A wiki of free games and related topics started by Han Dao.
• Open Source Game Clones - Open-source or source-available remakes of great old games in one place.
• Open source games (bobeff) - A list of different open-source video games and commercial video games open-source remakes.
• Open Source Games (trillarion) - A list of open source games, game frameworks and game creation tools.

Hi! I'm a software developer working on a suite of collaborative self-hostable apps to replace proprietary services I couldn't find a good replacement for.

I am writing this post to seek opinions and ideas now that I am still in the early prototyping phase, before it's too late to change track.

My idea is to develop a collection of simple single-purpose apps that do one and only one thing. The first app will be called Simple Notes (mirror), a replacement for Google Keep. Every operation is encrypted locally on the client, and the server never sees plaintext data. I am investigating federations models to let users connect to other instances and work collaboratively, much like Lemmy.

So, my goals in order of priority are:

• No compromises on privacy and security
• Completely FOSS
• Real-time collaboration between users
• Asynchronous collaboration (work offline, sync when back online)
• One account to operate on all apps in this suite
• Web UI / desktop UI / mobile UI
• Minimal interface which my grandma can use, no feature-bloat
• No anti-features such as advertisements, tracking, etc...
• Self-hosting
• Federation

After Simple Notes, I plan to keep developing other simple apps, some ideas on my list:

• Simple Notes - Replacement for Google Keep
• Simple Split - Replacement for SplitWise
• Simple Chat - Replacement for WhatsApp/Slack/Meet/Teams
• Simple Docs - Replacement for Google Docs
• Simple Draw - Collaborative drawing app
• Simple Calendar - Replacement for Google Calendar
• Simple Contacts - Replacement for Google Contacts (suggested by @Churbleyimyam@lemm.ee)

Initially I started writing my own protocol (mirror), operating quite differently from Lemmy's, but then I realized that someone else already has developed a protocol for this purpose: Matrix. It is (optionally) E2EE, it's FOSS, and it's federated. So yeah, it sounds like the perfect choice to me. Also, if I pick Matrix, Simple Chat will just be a reskin of Element, so development cost is almost zero.

So, a questions for the developers on the Lemmy Selfhosted community: do you think piggybacking the Matrix protocol would be a good choice? Do you know any alternative that might be more suited for this purpose?

And a question for all Lemmy Selfhosted users: is there a simple app that you would like me to add to the list?

Bonus question: do you know of any Lemmy community where I could repost?

Thank you very much for the time you spent reading my post!

--

Link to source code on my server and GitHub mirror.

--

EDIT: I might have been a bit unclear on my objective. My intention is not to just build a replacement for Google Keep, that's just the first step of the idea I had. My objective is to build a template from which it should be possible to build all sorts of apps to collaboratively work on documents of various types. Simple Notes (Google Keep) would be for text documents, Simple Split (SplitWise) for expenses (because a list of expenses is a document after all), Simple Chat (WhatsApp) for chats (oh yes, I would say that a list of messages is also just a document), Simple Docs (Google Docs) for... well... text documents, Simple Draw for canvas documents, and finally Simple Calendar (Google Calendar) for a calendar (which, why not, is also document!).

So yeah, I don't want to just find/build an alternative for Google Keep, I want to find/build a tool to build all sort of simple collaborative apps on top of.

What I am looking for is not the recommendation of an app to simply replace Google Keep, I am looking for a template or even just a protocol on top of which it's possible to build collaborative document-editing apps.

Yesterday, Spacemesh started circulating. Do you know about it? What do you think about it?

I have written this brief blog post to explain how it is different from other mainstream cryptos. Let me know if you have any questions.

(Also, this is my first post on Lemmy!)