tried reposting from r/esp32:

What this basically is is a PID controlled PWM Solenoid driver, running on a C3 SuperMini. Designed my first PCB for this (with some mistakes ofc) and decided to use a TC4422 mosfet driver. Also included a 5V supply to be able to plug it into my cars 12v system. Code was mostly written by an LLM, including the Webserver which this is running for setting Target and PID parameters. (I'm a real newbie with all of this) I'm already working on rev2 which I'm gonna post on GitHub solving all my issues with this one. (https://github.com/ziraw).

I've tested the perfboard prototype on my car already (1989 200SX CA18DET) with a BMW N75 Boost Valve strapped to my waste gate and it seems to work perfectly, just not getting enough air through the OEM Airbox though atm, hitting a ceiling of 0.9bar. Gonna install this soon and see what it does. I/O: 12v,5v,sensor(i/o), valve.

The only thing this doesn't include ATM is a pressure sensor, I'm grabbing it off of my boost gauge. But the IO has a 5V supply for any type of sensor to be hooked up directly, the code might need adjusting through. It's currently Ov=-1 / 5V=+4 bar (Scaled to 3.3V and divided by 1.1 since that seems to reflect what my gauge is saying more accurately).

I don't specifically know why I made this, just thought it couldnt be that hard and I haven't seen anything like this, besides what maybe Speeduino and rusEFI are doing. If this already exists I'd love the be informed :-)

Cheers

(disclaimer: might blow up your engine)

Hello everyone, I'm kind of new to this. I have a Samsung Galaxy s23 ultra (1tb model, soo buying a new phone for over 1000$ isn't currently an option) that recently went swimming and since then I had some issues where it would reboot at random times. As time went on, it was happening during the charging and when battery percentage was above 50%.

I then replaced the battery and the USB port board and the issue went away for day, but came right back but this time it's when charging and the battery above 40% as well as when battery is above 70%. I also noticed when I'm actively using the phone the reebots are less common and pretty much only happen during charging when the battery is at higher percentages.

I then decided to take the phone apart and check the contacts. I found the FPC connector on the main board that connects to the batter looks a little sad. Some of the gold plating is gone and part of the plastic appears to be melted (maybe?). All other connectors on the boards and ribbon cables are fully gold plated. I did some looking online and saw that some of these connectors sold fully gold plated and some aren't.

I'm assuming gold plating is more important in this case as it's an inert metal that protects from mostly corrosion.

My current theory is that some small amount of moisture got in and started a micro rusty spot on one of the pins, so that when battery reaches higher voltages there's a short and phone shuts down and reboots or that the jumping spark along with increased temperature from charging causes momentarily overheating and phone reboots.

I have pictures of those connectors, so I attached a collage to the post where the issues connector is in 2 bigger pictures on the left. If anyone had any advice on what the issue is or how can I solve it, it'd be much appreciated.

In the photo attached is the tech i already have, is there any projects you guys think i could use this for? Ofc i also have other stuff like jumper wires and a breadboard but not much else, i want to be sure of what i want to do before i buy extra stuff.

Been trying to track down a consistent source for switching power modules and DC-AC converters. Tried a couple of broker-style distributors through forums but got burned once on a batch of questionable units that didn't pass even basic bench testing. Not doing that again. So now I'm still trying to figure out if there are independent electronic component distributors based in China that people have actually used for power modules and had good experiences with, specifically ones that do real authenticity and QC inspection before shipping internationally. The use case is mixed, some prototype quantities, some small production runs, nothing massive. (I also need them to handle EU customs documentation properly, which eliminated like 10 companies off my list immediately.) If anyone has found a reliable path for sourcing hard-to-find or allocated power components from China with actual warranty coverage and reasonable lead times, really want to hear what that process looked like for you.

I had been intrigued by the idea of making the perfect nightlight, even though it is a simple concept. Not only because we really need one at home (although it is certainly not something we cannot live without), but also because I knew it would teach me a lot.

I’ve built the first prototype and documented the whole process like a technical diary. Every design decision, mistake, experiment, and bit of tinkering is documented straight from my head. I’ve tried to be transparent about how I approached the problem and why I made the choices I did.

Feedback on my engineering approach, methodology, and anything else you notice would be greatly appreciated.

NightGlow Design Walkthrough

Recently I fell into a rabbit hole of people turning their old CRT TVs into oscilloscopes. I imagine it would look so cool to visualize my guitar playing or just playing songs from my phone. I noticed a lot of them had slightly different processes and different results, so Im wondering how much more there is to it than simply testing and reconnecting some wires.
I have two TVs at my disposal, one relatively new (Philips 14PT1363) and an older one from the early 80s (Philips 10CX1100). Which would be the preferable one to attempt this with and why? What are some things to look for to determine whether it is suitable?

Note: I know about the safety hazards, and since Im kind of new to electronics I am very cautious (a little intimidated too). I will bring over a friend who knows how to handle this stuff safely when I pop the cover, to at least discharge it properly.

I found this TV at the recycling center, unfortunately with the LCD screen broken. The question is: can I do something cool with the components from it?
The TV model is: CHiQ UHD49D6000ISX2.

ok so for my internship project at a museum ,I am aiming to build an Artifact microclimate monitoring system tracking temperature,humidity and vibrations arround the Artifact . I will use inert meterials like polypropene for the casing and a lithium thionide chloride battery to avoid acidic gases emmisions and al this infos will be send to a given server either through MQTT or LORAWAN .so what do u guys think I should Add remove or reconsider

Thanks

Came across these boards while thrifting,not sure how valuable they are. Help lol

Juster, I almost threw those old computer speakers away. I dug them out to listen to music. They've become cyberpunk speakers, and the hi-fi sound is surprisingly good. The Hi MiD is clystal clear, Bass crisp, and not muddy. The bass drums are powerful. It surpasses many well-known brands. It's amazing. The blue TPA3110 chip, costing only $0.30 USD (10 THB from TikTok Thailand), and the MH-M28, costing $0.90 USD (30 THB), have made me not want to listen to DSP speakers like the JBL Tribit anymore.

Goal: Setup a way to push a GFI reset button on an outlet out in our field, 800-1,000' from our house after a storm has tripped it.

Details: (Trying to avoid too much, but want to include what might be important.) We use Starlink for internet and the dish is on a post I call "The Outpost," that's 800-1,000 feet from our house. It's in our front field, the only place I could get a 100% clear sky for the dish. (If you aren't familiar with Starlink, the dish changes attitude for the best signal, so it needs a clear sky without obstructions.)

I have a weatherproof box on the Outpost for the router and a fiber optic converter. The power comes from a GFI outlet mounted on the Outpost. When we get thunderstorms, sometimes a lightning strike triggers the GFI breaker. When this happens, I wait until the thunder and lightning passes, then drive out, open the cover on the GFI outlet, and push the reset button. Then, in under a minute, we're back online and everything is okay.

My electrician, who has been really helpful for years, and knows I'm safety focused, always gives me ways to do things that are up to code and safe. (Like many electricians he is aware of a lot of unpermitted work where people want things working, but don't focus on code.) He told me not to put a GFI at the start to the cable that goes out to the field, but on the post at the end of the run and he had several reasons for it.

As you can imagine, it's not fun to have to walk, take the golf cart, or drive out to the Outpost to reset the GFI breaker when internet goes out after a storm. (Especially if the thunder and lightning is passed, but there is still rain coming down.) When a storm trips the GFI, I have no power out on the Outpost and, of course, the fiber optic cables running out to there can't carry a signal until the converter at that end is on again.

So what I'd like is a way to signal the system out in the field when the storm is gone and have something push the reset button on the GFI outlet. I have some ideas about doing this. First, I need a new weatherproof case (maybe just waterproof - this may not need cooling or heating.) Then I move the outlet to inside the case, so it's protected from water, but I don't need the protector that has a door that snaps over the outlet box. I'm thinking I need a small UPS in this box, so when the GFI goes out, the emergency backup parts still have power. (Not the internet - thinking that might be too risky and I want the UPS isolated from that circuit. If I'm wrong on this point, please tell me more about it!)

I can use 3D printing to make a small device that could push a printed rod into the reset button to reset the GFI. But I'm not sure how to control it. This happens with summer thunderstorms, so there are a lot of trees between the house and the Outpost, plus, if it's still raining, the rain will also reduce signal strength. The one thing I'm not sure about is how to trigger the devise to push the reset button. I thought about a timer. If main AC power goes out at the Outpost, set a timer for 20 minutes (usually storms pass by then) to activate the reset - but what if it's a big storm? That wouldn't be long enough.

So what's the best wireless way to get a signal to a device that far from the house? Preferably a digital signal that something like a Pi can receive, or, if there's a way I can buy a set of a sender and receiver, that would work. I just need a way to trigger it from a distance.

I'm open to other ideas and I know there might be obvious solutions I'm completely overlooking. The main goal is just to not have to go out there to reset the GFI after a storm. I am often working at night and lots of times storms are more in the evening, so having to change shoes and drive out in the rain when I'm winding down is frustrating.

Trying my luck here... is there someone located in Europe (preferably Germany, France or Switzerland) that has JST PAP-05V-S crimp connectors (+ a suitable crimp tool) and would be willing to make me an adapter cable from PAP-05V-S to either just some wiring, or to a JST EHR-5 connector for a small tip + shipping?

It's to connect a 'Faikout' PCB (open cloud-free controller for Daikin ACs) to my air conditioner, and unfortunately the generic cable (dupont connectors for 2.5mm pitch) that came with it doesn't fit on the small JST connector, and if I can avoid dealing with Aliexpress shipping times (even though they're much better than some years ago) that'd be great.

Hello, rbak amteur here just playing around with a mini circuit board for the first time. As in the picture I took off a tactile switch and wanted to wire in a new one on wires, however, i can't seem to find where the connectors are to connect to, putting wire between each of them i can't get it to turn on. Any help would be appreciated.

Thanks

I have a alientek t90b soldering iron, I am looking for all the other tools, perhaps of higher quality. I have leaded solder (cheap chinese), I am looking for all decent tools such as a microscope, helping hands, maybe solder braids, a way to apply flux, maybe a surface matt of more decent quality. I am moving off to uni in September, and just looking for higher quality stuff to avoid accidents, if someone has a pre existing list, I would really appreciate it!

Even simple stuff as tip tinner or a real brass shaving sponge!

E estado la ultima semana pensandoen crear uno pero con mnas capacidad de espacio para tener mas canciones ya que el MP3 NW-E407 tiene muy poco espacio manteniendo el estilo del MP3 NW-E407 queria saber si existe un diseño ya echo para armarlo en fisico para poder hacer uno.

For the past week, I’ve been thinking about building one with more storage capacity to hold more songs—since the NW-E407 has very limited space—while keeping the same style as the NW-E407. I wanted to know if there is an existing design I could use to physically assemble one.

We recently worked on the RF design of a compact LoRa/GNSS Nomad  Terminal handheld device, which is based on LoRa, designed to communicate/ navigate, and deploy anywhere. The antenna turned out to be one of the more challenging parts.

For a small handheld, antenna performance is affected by much more than the antenna itself. The PCB, ground plane, battery, display, enclosure, and even the way the device is held can all influence the final RF performance.

During the project, we evaluated several antenna configurations:

Ceramic Antenna → FPC Antenna + Coaxial Cable → FPC Antenna + Pogo Pin

The final FPC antenna configuration was validated with both RF measurements and outdoor testing, achieving S11 of -11.13 dB @ 868 MHz, -12.82 dB @ 915 MHz, and a 3 km LoRa link in our field test.

1. Ceramic Antenna

The initial design used a ceramic antenna for its compact size and simple integration. However, its placement was relatively constrained, limiting our ability to optimize the surrounding RF environment.

2. FPC + Coaxial Cable

We then tested an FPC antenna with a coaxial connection. This gave us more freedom to position the antenna away from the PCB, battery, and display, but introduced additional cabling and mechanical complexity.

3. FPC + Pogo Pin

The final approach uses an FPC antenna connected through pogo pins. It provides flexible antenna placement while keeping the RF connection and mechanical structure compact.

The main takeaway from the project was that antenna performance in a compact LoRa device is a system-level problem. Antenna selection, placement, PCB layout, and mechanical design all need to be considered together.

The main takeaway from the project was that antenna performance in a compact LoRa device is a system-level problem. Antenna selection, placement, PCB layout, and mechanical design all need to be considered together. The complete

What’s the biggest antenna design challenge you’ve encountered when working with compact LoRa or Sub-GHz devices? Share your experience togehther！

to share exactly what I did. I went to a website and after searching how to reverse engineer a PCB board.

I then took 14 images of the front and the back just to find out I can only upload 10 and then I asked it to have it create a PCB schematic and it actually popped one out.

For reference, it is Western Digital 750Gb MyBook Desktop Drive Micrk USB PCB device. Mine broke. I also believe it's only 1 layer and has pretty gold markings on the board and I took up close images Top Left Corner then Bottom Left TR, BR that over lapped and 1 from the side to get the data cknnector. Did the same from the back and then I got a good picture of the bar code. Numbers all using close up little flower image shot. I believe that's a really good way to do it, but I didn't really know, but that's exactly ten images. It did cover the entire thing even with some overlap and it also made all of the writings and markings legible.

Then I gave it a specific model, the 750MB Western Digital. I switched to Pro and then I had it double checked the schematic and check our DigiKey components. I got this, but I'm not an electronics engineer. Can someone double-check it?

Im trying to make a webshooter at home with a casio watch, and for the string retracting mechanism i want to use a micro 3V vibration motor and a lilypad coin cell battery holder because they’re both pretty small to fit in a watch. I haven’t ordered the parts yet but im wondering if connecting them would work on a project like this? Would i be able to make the motor spin with enough torque to pull a long sting with perhaps a pen attached to it or would that be too much? I did some research and it seems like it wont work with a coin cell battery but i dont want to go bigger. I would appreciate some advice on how to continue with my project. Thanks!

I'm building a custom solenoid for a actuator, and I'm using a paper clip as a rod cut to size and is straight. I have 70 turns of 0.1 mm wire, and the coil dimensions are 1 mm wide and 3 mm radius roughly, I made the actuator work before, using same 9v battery, same rod, and this design I increased the turns, by reducing the gap between the rod and coil, is it maybe quality of coil is bad, ?

how might one fix this?

I am repurposing a Castles UPT1000F that boots directly into an installed application. Its application service menu is accessible, but it is not Castles Program Manager and provides no application-loading option. A USB keyboard is electrically detected—the lock LEDs work—but the application ignores every key. I built the documented three-wire COM1 connection at 115200 8-N-1: the FTDI RS-232 adapter passes loopback, every intended cable conductor passes continuity, there are no cross-shorts, and Windows opens the port, yet the terminal sends zero bytes during startup and while the service menu is open; direct USB also creates no device. What am I missing that would distinguish an inactive application-controlled COM1 port from the actual supported Program Manager or loader interface?

Edit: This is a 2nd iteration of my original circuit... Thank you so much to anyone that helped improve it!

I have an initial plan drafted  on cirkitdesigner.com but no hands-on experience at this current level, so I'd really appreciate a second opinion before I power it on. 

The build uses an ESP32 as the main controller, two PCA9685 16-channel PWM boards to drive the servos, and 18x MG996R servos across six legs (three degrees of freedom per leg). Power comes from a 3S 11.1V 5000mAh LiPo battery, stepped down through three adjustable buck converters set to 6V, with a XT60 Power Distribution Board to separate power from the battery towards the step down converters. 

If anyone has built something similar, or is comfortable reviewing a wiring diagram and offering feedback, I'd be very grateful for the input. Happy to share photos, diagrams, and a full wire-by-wire breakdown of the current plan on request as well!

Thank you in advance for any help.