You make a copy of the code (“fork”) for yourself, make edits, then request that your changes be accepted into the original project (“pull/merge request”). Someone from the project has to check the edits, make that decision and hit accept or decline.

I duckduckgoed “SOT23-6 boost converter” and found a picture of an IC with similar markings - I’m now pretty sure the component is an FP6291 switching regulator by Advanced Analog Electronics.

If you look on page 3 of the datasheet, the “AL” identifies the part, and the following numbers are the year of production and the wafer lot number, so they could really be anything. The pinout matches as well, given a few inaccuracies in your schematic, which I think I can confirm on the images. Thanks for the image of the PCB against the light, that was very helpful.

Pin 1 would be on the bottom right, connected to the inductor L1 to boost the voltage, with the other pins arranged counter-clockwise. Pin 2 should then be connected to your PCB ground; to confirm, you could use a multimeter in continuity mode to measure to the BAT- and 5- connections. The right side of R4 should also be connected to ground, and 24 kΩ would set the current limit of the IC to 2A (page 7). On pin three is one of the mistakes in your schematic as far as I can tell, I think that pin is really connected to the point between R6 and R5, for output voltage feedback. I also think R6 is meant to read “84D”, which would be the resistor code for 732 kΩ with 1% tolerance. If you calculate the output voltage of the regulator with the 0.6V feedback voltage from the datasheet and 732k/100k resistors, it comes out to 4.99V, which would be compatible with the USB 5+/5- stuff. Connecting EN to VCC (pin 4 to 5) is also common to permanently enable an IC, but I think there’s another error in your schematic: I’m pretty sure those two pins are directly connected to BAT+ instead of through C4, and that C4 instead connects from those two pins to ground to stabilize the input voltage.

Edit: Would you post of link to the product on AliExpress? I’m interested now :D

There’s no way U1 is charging the battery. How would it? If the connection labeled USB is the power source, it’s only connection to U1 is through a 100k resistor and a reverse biased diode. Also, charging AA batteries? Sure, you could plug in some NiMH cells, but then the device would need to have explicit instructions telling you that this is indeed a charger and to only ever insert rechargable AA battery cells.

If you desolder U1, you should drop about 0.5V of your battery voltage across D1 and maybe the remaining 2.5V will be enough for the other components to do something, but I doubt they will be very effective in whatever their purpose is.

Feels an awful lot like a step-up converter. I’m missing the ground connection though and potentially a connection to a voltage divider for feedback. Where does R4 lead to? Are you sure there is no connection from the middle right pin except to C3? Is pin 1 of U1 marked? Can you make a detailed photo of the IC to better identify the text on it?

tl;dr: I’m reasonably sure this will work as is.

The following comments involving my personal opinions might be most useful for more complex projects:

While I also try to isolate building blocks in my schematics, I think it’s sometimes beneficial to have some visible connections using wires. Your schematic isn’t very complex, but I still needed to jump around a bit to understand how current flows from the USB connection to the output. I would arrange the building blocks so that current flows from left to right and include one wire that starts at the USB jack, passes by the CH224K and its bypass cap, through the FET to the terminal block, so you can read the current flow like you would a line of text.

Layout:

• Before manufacturing, better before starting the layout, I would include the design rules of your manufacturer under File > Board Setup > Design Rules > Constraints. Currently you haven’t defined minimal clearances, widths etc. Google “[your preferred manufacturer] capabilities”. You might also find existing KiCad templates that you can import.
• I would place the reference designators on the silkscreen so they are visible after assembly, to help with debugging and repairability.
• I would also take care that everything you want to show is legible; currently, your JP-labels overlap U1
• To find enough room on the silkscreen, you could probably reduce your text size. Look up the minimum in your manufacturer capabilities; in addition to putting those values into your design rules, you can also add them in File > Board Setup > Text & Graphics > Defaults > Silk Layers. Apart from that being the new standard, you can then also easily go to Edit > Edit Text & Graphics Properties to set all existing reference designators to those new default values. In my personal experience (with JLCPCB at least), the text also stays legible waayyy below the quoted minimum size.
• I make it a point to include some metadata on all my PCBs; a version number, date, a project title and the name of the designer, so I don’t confuse myself or others when the PCB is found some years later in a random box.
• I like your package size for the resistors and caps, but if you have space issues, you will probably have no issue soldering the smaller 0805 packages by hand either. We regularly have discussions what size can be comfortably soldered by hand without magnification; one of my colleagues insists that even 0603 is “comfortable”.
• EDIT: Your trace from the capacitor to the VDD pin of the IC is a bit long. It will work, but it would be better to place the capacitor as close to the IC as physically possible, so that the area enclosed by the loop “Cap.+ -> IC.VDD -> IC.GND -> Cap.GND -> Cap.+” is minimized. Something like this:

Regarding both the schematic and layout: run the ERC/DRC and fix all errors and warnings. Most of it is noise, but hidden beneath that, serious issues can hide. Be sure that you don’t miss anything important there.

Another idea that might be out of scope for your project: You could add optional 5.1k pull-down resistors on the CC lines and a solder jumper from VBUS to VOUT. Then you could use the board even without the CH224K and the FET if you only need 5V.

I know nothing about Irish, but this reminds me of the diminutive in German. There it would be

Rose - Röschen (little rose)

and likewise

• Brot (bread) - Brötchen (small bread)
• Haus (house) - Häuschen (small house)
• Katze (cat) - Kätzchen (little cat/kitten)

You could also translate “little rose” word by word as “kleine Rose”.

The sole purpose of this grammatical form is to make something sound smaller, so you can’t extend it to other adjectives like “red”. “Little red rose” could be “kleine rote Rose” or “rotes Röschen”.

Oh god, this answer has gotten longer than expected.

How is it? All in all, it’s good here. I’m confident that it would be difficult to find a significantly better country to live in. But it’s not perfect either and many people fear that it will go downhill from here.

Many parts of industry and research are struggling while a lot of money is pumped into the military. Our infrastructure is mostly still good, but, for example, we’re having trouble keeping up with a lot of old bridges nearing the end of their lifespan. The population is getting pretty old as well and healthcare costs are increasing. They are shutting down our local hospital to save costs and shifting the patients to a big new clinic, which is currently being constructed in the next bigger town. Rents and house prices in the big cities are enormous. In the countryside, internet and public transportation is lacking. Many people are dissatisfied with politics, which led to huge gains for the far-right AfD party, especially in the former GDR. They blame immigrants and the EU and the green party. What has always been an issue is bureaucracy. Complex, unflexible regulations and matching civil servants grind many things to a halt. Part of the problem is a refusal to adjust to new, digital processes.

On the positive side: Food is relatively cheap. Some prices have been coming down again since Covid; butter is down to 99ct/250g, pasta to 49ct/500g. Medical or educational debt is unheard of. The mother of the family next door, a Brasilian woman married to a German, just had brain surgery before christmas. l suppose the additional cost for her family was around 70€ (10€ for every day in the hospital). I studied Aerspace Engineering, about 200€ per semester. I have never witnessed any violent crime, nor has any close friend or family member for as long as I have been alive and as far as I know. Same goes for theft. The worst thing I can think of is a class mate back in school who told me he was attacked with a glass bottle and robbed at night at the train station. I’m sure I live in a bubble, but the people I have contact with are honest and have what they need. I recently lost a 50€ bill at one of the social clubs in which I’m active. Instead of pocketing it, someone picked it up and put it on a counter. Then someone else took it and went through the rooms to find the rightful owner. And while the price of the “Deutschland Ticket” is steadily increasing, it is something I really enjoy. It exists since Covid and allows you to use all (non high speed rail) public transportation in the entire country, for now 63€ per month.

Immigration: For a long time, immigration to Germany was not only tolerated, but actively promoted in Greece or Turkey. In the last decade people fled from Northern Africa to Germany, and in the last few years I noticed a lot of Ukrainians for obvious reasons. This of course changes society. No matter what you think of that, our aging population is a problem, and young migrants are a potential solution. Of course there are also criminal people among them, but I don’t know the statistics for migrant/long-time-German crime, and I don’t notice crime here anyway. If you want to experience crime for yourself, go to Frankfurt central station.

Regarding my town: I live in a small town of about 30000 in Baden-Württemberg in southern Germany. It’s not that exciting here, but we have a bunch of schools, an outdoor and indoor swimming pool, at least 5 supermarkets plus a few drug stores, all kinds of doctors, a library, churches and mosques, a skate park and soccer fields, a lot of social clubs and a beautiful old town center. The old town was built around a small mountain. At the top lie the ruins of the old castle, and in the summer after sunset, it becomes an outdoor movie theater. That’s part of some bigger festivities each summer. The newest addition to the town is a funny tower built on a mountain of trash, our former landfill. Great for watching the sunset or sunrise, although nightly visits are not officially allowed. We have a stretch of no-speedlimit Autobahn starting here and a train station. The Autobahn takes you to the next bigger city in about 20 minutes, there you can find more fun stuff like night clubs, a normal cinema, an Ikea and a lasertag arena. 40 minutes of train ride brings you to the state capital for even more shopping and night clubs, or to the international Stuttgart airport.

What do I do? I dance at our sports club, I go shooting once or twice a week at our sport shooting club, I like learning languages. We also have what we call a youth research center. I teach electronic circuit design to a group of pupils, others teach software development or mechanical design. I also work on a robotics project together with some university students, and we can use the workshop and tools for our own projects as well. Doesn’t cost anything to the students, everything sponsored by local companies, foundations and the government. This youth research center is btw sandwiched between housing for migrants and asylum seekers. I’m there twice a week, and I haven’t seen or heard about any problem during the last ten+ years. The only thing noticable is lots of playing kids and really good smelling food being cooked.

I’m not sure about animal sanctuaries and no-kill shelters, but the rest sounds like Germany.

Of course it’s not perfectly just and equal etc. here, and of course community and crime rate depends on where exactly you are, so to be more precise: small city/village in southern Germany.

Ich liebe Regex, aber es ist gleichzeitig ein gutes Beispiel für Write-Only Schreib-Nur-Daten

With a PMOS device used for simple on/off switching, placing the load between drain and ground would be correct. With an NMOS FET, the load should be between drain and VCC.

In general: NMOS source to GND, PMOS source to VCC.

Props for the detailled answer, but this all sounds completely backwards.

Low-side switching should in general use an N-Channel FET. And with your voltage divider, the gate will be at 9% of the supply voltage, not 91%, which means the FET will always be conducting. It will also never fully turn on, because that would mean the Gate-Source voltage would drop to near 0, which would turn it off again - it will instead settle somewhere near the GS threshold voltage from Drain (and Gate) to Source. Moreover, PMOS devices are not controlled by the Gate-Drain voltage, but with the Gate-Source voltage, just like NMOS devices.

My counter proposal:

Edit: Note that this is an N-Channel FET

Edit 2: Changed image, I initially placed the resistor and the tripwire the wrong way around.

I noticed that I glossed over your breadboard requirement. If you want to use something like an ATtiny or CH32, you could always buy some generic SMD breakouts like this. Both of these microcontroller series have internal oscillators and flash memories, so you really don’t need any external components. Maybe a bypass capacitor for good measure.

If networking is the goal, choose any ESP32 module. If you want something simple akin to an ATtiny, ich can recommend the CH32V003. Is has plenty pins and an I²C peripheral, costs around 15 ct. For accurate timing, add an external oscillator instead of using the internal one.

Edit: You could also use an external real time clock like the PCF8563, then you’d have an absolute datetime and wouldn’t need accurate timing on the microcontroller itself. The buy the CH32 (and anything else), I would choose lcsc.com

Maybe I should have included another object for scale. It was advertized as a grapefruit of variety “Sweety”. According the Wikipedia it’s also known as an “Oroblanco”, and the color is typical. In any case it tasted alright for a foreign fruit in winter for 79 cents :D I liked that the flesh was very easy to scoop out.

discuss.tchncs.de is tech-focused :) It seems like there are no communities for games and comics yet though.

I also daily use Firefox, Thunderbird, VSCodium, Signal, KeepassXC, DAVx5 and Radicale for calendar syncronization.

What I don’t use each and every day but what are among my favorite FOSS projects are KiCad for electronics design and CoMaps for navigation.

Linux, or as I’ve recently taken to calling it, Linux.

Removed by mod

Removed by mod

Removed by mod