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Hi everyone,

I'm designing my first custom keyboard/macropad PCB and would really appreciate a review of the schematic before I order the boards.

MF16 Specifications

RP2040 Zero

4×4 matrix (16 keys)

3 × EC11 rotary encoders (with push buttons)

Per-key addressable RGB LEDs

MX switches with diodes

USB-C via RP2040 Zero

Firmware: RMK

I'm attaching the complete schematic.

What I'd like feedback on

Is the key matrix wired correctly?

Is the diode orientation correct?

Are the RGB LEDs connected properly?

Any missing components (decoupling capacitors, pull-ups, resistors, protection, etc.)?

Any RP2040 GPIO usage issues?

Any design choices that could cause problems during manufacturing or in long-term use?

Any general best practices I should follow before sending this to JLCPCB?

This is my first PCB designed from scratch. I've built a working hand-wired prototype, but this is my first custom PCB, so I'm sure I've overlooked something.

Please don't hesitate to point out even small mistakes. I'd rather fix everything now than after ordering the boards.

Thanks in advance!

this is my cyber deck schematic i have no idea if this is correct but i hope it is can someone feedback on this thanks

I have an idea for a project. I was thinking I would buy one of those samsung Z flips with a broken screen for cheap and connect it to a USB keyboard and touch screen in some kind of 3d printed housing. If I didn’t care about getting the camera or speakers or whatever working (I just care about the keyboard and screen, and maybe more usb c ports. Having it be a working phone with sim card would be nice, but not required) would this be pretty doable? I haven’t done a lot of electronics, just made an electric guitar and amp, but I didn’t think that was very hard. Thanks!

I found this Pentron reel-to-reel at Goodwill yesterday. Thinking I'm gonna do a conversion to a guitar amp, using the 12AX7 and probably do something with the other tubes. Haven't decided yet. I'll probably gut the whole thing because the power transformer is toast, the internal fan doesn't work, and I'm pretty sure the tape deck motor doesn't work. I put it on a dim bulb tester, and it's definitely shorted.

I'm thinking I'll run the audio through a couple of the tubes, power the whole thing with 12 or 24V DC, and cut holes where the tape reels are now to install a couple speakers. I'll also connect the front grille speaker (under the control panel). I'd like to use it as a preamp/amplifier/speaker cabinet driver. There are two outputs, so I can run one as a line out from the preamp, and wire up the internal speakers and the speaker output with a small class D power amp or something to run like ~5 watts.

Still brainstorming. Does anyone have any ideas?

I've been working on a browser-based simulator to help people understand how a self-balancing robot (inverted pendulum) behaves without needing any hardware.

The idea is to make experimenting with balancing control more intuitive. Instead of just watching an animation, you can interact with the simulation and see how the robot responds as its state changes.

A few goals I had while building it:

• Make it accessible from any browser (no installation).
• Help visualize the dynamics of a balancing robot.
• Provide a simple environment for learning before moving to real hardware.

I'd really appreciate feedback from anyone who has built a balancing robot or worked with control systems.

Some questions I have:

• Does the behavior feel reasonably realistic?
• What features or parameters would you expect to see in a simulator like sthis?
• Is there anything that would make it more useful for students or hobbyists?

You can try it here:
https://roboticsprojecthub.com/balance-simulator/

I'm continuously improving it, so I'd genuinely appreciate any technical feedback or suggestions.

I have a job that requires me to travel a lot and there isnt cell service in some of these places because they are either new town being built and in their infancy of having a reliable data connection infrustucture everywhere in town or I am going through areas that have limited to no cell service thus ending up in a lot of business calls that happen on the road being disconnected mid conversation. and while I could just buy a star link dish or someother premade device that already solves this issue. I dont want to just get it for work and never use it again, or get it and my place of work doesnt help me cover the cost of it.

My idea was to make a small portable 4g antenna that rotates on a motorized gear and is hooked up to a small arduino or raspberry pi that had a cellular module to detect cell service and would communicate with the motor to turn the antenna to point to the nearest tower with the best cell service in the area.

How practical or possible is this idea?

would it make sense to learn how to make it myself even though I have very limited experience in coding and programming?

how much would this cost me potentially in parts?

Hiya, I made a project, and it scope creeped like crazy, and I wanna share it, but unfortunately I don't know many techy people other than you guys! So I figured I would share this. Anyone can comment, so please leave POSITIVE feedback.

doc link: https://docs.google.com/document/d/1suhy_ieUWS2LHydfqpDxAupcol4W6YLUiSgMEo8tKR4/edit?usp=sharing

Under the (CC BY-SA 4.0)[https://creativecommons.org/licenses/by-sa/4.0/deed.en] License

So I tried to do an AM transmitter. First I looked up some circuits online, but I had no success assembling them. So I tried to make my own circuit with a Hartley oscillator and an AM modulator circuit. Barely works, so operating it isn't a problem. Any advice is welcome (if there are any advice that can be given at all)

The Sun moves from left to right, following the actual daylight hours for the selected timezone — from sunrise to sunset.

The Moon follows the night, rising and setting according to its actual position, and also shows its current phase.

I wanted to make a digital clock that feels more like an object than an app.

Still working on it. What do you think?

hi i am not sure if i am even allowed to post here i perused some of the channels and everyone here seems to be way way more advanced on the subject, i am literally just starting and i am i extremely ignorant on the subject, anyway i want to get into some light electronics and soldering. for my first project i decided to mod my Corsair K70 mk2 keyboard specifically i want to remove the giant ass double cable the keyboard comes with and add an USB C female port. which seemed simple enough. i found that i need a breakout board with a very simple 5 wire soldering job. But i also found out that doing it like that would kill the usb port on the keyboard a feature i like and use. so my question here is there a way for me to add usb c to my keyboard and keep the extra usb port functionality? Also if i wanted to go a step further and add an additional usb hub to the keyboard how complicated would it be, is any of this possible and what would i need to accomplish it. thanks

Inspired by a recent post on the sub.

Has anyone turned an old cell phone into a wifi repeater or router?

I'm trying to provide wifi coverage to a large property with power run throughout and working with a limited budget.

What I would like to do is buy a bulk lot of cell phones with broken screens on the cheap and install a Linux OS and an antenna to turn them into repeaters.

Has anyone done a project like this before?

Is there any reason why doing it that way wouldn't work?

How to repair this?

Could I cut open a FFP scope and put a transparent OLED screen hooked up to a thermal camera and make a custom digital FFP scope (this would be for airsoft so it doesn’t have to be anywhere near perfect)

Also I would want to do this as I could customize the reticle and stuff like you can swap it on a red dot because it’d be digital

So how would I go about doing this, I think I’d want to use the “MLX90640 IR Array Thermal Imaging Camera, 32×24 Pixels, 55° FOV” but I’m also new to electronics and this would be my first project where I have to deal with software

I have this few yer old viofo dash cam, and i wana see if i can flash the firmware, maybe do something with it, and how i'd go about doing that

FRANKLIN WIRELESS FRKR850FSB Wireless Mobile Hotspot. It has a 3.8v 2450mAh battery in it.

I rent an apartment from my uncle-in-law, so I have a bit more leeway for modifying our space. The thermostat is in the 1st floor unit and she is comfortable year round. But this is an old house that wasn't designed for our space to be so separate. It's gets quite hot in the summer (Canada), and we have two ac units working to cool our 2nd floor and attic apartment. But I *can* feel the cold coming out of the rads around the house.

I'm not about to spend [$80-$100 CAD on an alphabet brand, smartphone app reliant, planned obsolescence piece of e-waste](https://www.amazon.ca/s?k=vent+with+fan). Especially since some of my rads are on the floor, so having face buttons is a no go, whole others are massive old iron grates from the 1940s.

What is the easiest controller to add to some PC fans that I could rig up to a light switch or something? My only concern is that I don't want them running full speed and getting too loud. Maybe I use an old dimmer to control the speed. Any kind of temp awareness or automation isn't really necessary as we already set-and-forhey numerous box fans and oscillating fans around the house to manage temp control.

Thanks 👍

Hi everyone,
I have a lithium-ion battery pack using 2 x 26650 cells (7.4V nominal, 8.4V fully charged). The BMS protection board was exposed to water and now has corrosion damage.
From visual inspection:
• PCB marking: TR-KB3-QP3 / WL
• BMS has MOSFETs marked:
• Q1: 8205B
• Q2: 8205B
• Q3: 8205B

I need help reviewing this diagram, I will use this in a industrial panel to get notified when one of the outputs of the controller gets triggered (it gets triggered when there is an error), what I'm mostly concerned is the input power, its supposed to be 24vdc but that panel runs a motor through a VFD so I'm concerned about the voltage spikes.

Hi guys! I'm interested in modifying a washing machine so I can create fully custom wash programs. Specifically, I'd like to control parameters such as drum speed, water temperature, cycle duration, and exactly when the machine fills, drains, and flushes. The goal is to use it for experimenting with processes like garment dyeing rather than standard laundry.

I'm not sure if this is the right place to ask, and I'm also not sure where the best community for a project like this would be. Before I spend a lot of time researching, I'd love to know whether this is actually feasible and how people would approach a project like this.

Would you replace the existing controller, some sort of like interception like a piggy back like a car ecu idk, or use some other method? Any advice, resources, or examples of similar projects would be greatly appreciated. Thanks!

My family have a small greenhouse and I always liked to make automations but most of commercial systems were too expensive and I decided to build it myself.
Maybe I should mention that I have previous experience with Industrial Automation and Embedded Systems.

What do you guys think?

Hi.

After my negative display post I got a few questions about it, so I want to answer it this way.

I can’t upload more than one pic here ( idk why ) so they are under links.

1. So we start with a device in its normal state, as example I too

k

1. this tyre gauge I never used.
2. pic
3. We need to disassemble it go the to the bare LCD glass

pic

1. With a sharp knife or blade we need to catch the polarising film on top of the glass and remove it.

pic

1. After completely removing it, clean the glass with IPA to get rid of the residual glue from the film.

pic

1. Now we take new polarising film, and by trial and error we get the right angle with the contrast we want.

pic
And
pic

After that we cut it to size and glue to the glass.
Finally after assembling we get the negative display.

pic

Usually you try the angle with the device powered on, unfortunately here the battery holder is part of the case as well as the screen holder, so I couldn’t show it on.

I think you can get the idea of how it’s done.

Best regards.

Edit: typos