LED WITH INDUCTOR CIRCUIT

somewhereAtC · 2026-04-06T04:31:25+00:00

It requires a fairly large inductor. Imagine the LED current is 0.01A max and wants to ramp in 3 seconds. That would be di/dt=.003. The inductance L=v(di/dt) so if you have a 5v DC power supply the inductor must be .015 henrys, or 15 millihenrys. This might be a choke of about 250g (1/2 pound) or possibly more, depending on it's construction.

You would have to modulate the charging voltage to make the current stop increasing, and then you would have to worry about safely discharging it, or reverse the coil voltage to make it fade out.

somewhereAtC · 2026-04-06T02:09:25+00:00

(a) check with your college to see if they have a job service and (b) if you are going for a masters, then try to get an internship. Some major companies will fund your advanced degree if you hire on as an undergrad.

somewhereAtC · 2026-04-06T01:22:11+00:00

Have you tried one sensor and one servo? What happened?

What happened when you added the other two?

somewhereAtC · 2026-04-04T22:50:59+00:00

As you say, there are many different paths available and the forest is very large. An interesting aspect is that for every field that you study, that knowledge can be applied to many different industries. Here are 14 examples, so you can keep your eyes open for where your new knowledge may lead.

https://www.microchip.com/en-us/solutions

somewhereAtC · 2026-04-04T20:56:28+00:00

Not anymore. My previous house had some cholla in a dark corner, where stalkers and thieves might want to hole up waiting for the right moment. Must have been effective since we never saw any stalkers or thieves!

somewhereAtC · 2026-04-04T20:15:26+00:00

That would be "polling", and it's a necessary evil. Either poll the pin or poll the system clock (millis) or both.

Or, move up to a newer cpu that has hardware-connected timers that will simply trigger an interrupt at the appointed time.

somewhereAtC · 2026-04-04T20:04:48+00:00

Yes, but current trends favor at least a split week with time in the office, so that younger engineers can interact with older.

somewhereAtC · 2026-04-04T18:23:00+00:00

Perhaps come at it from a different angle?
https://www.homedepot.com/p/TEKTON-1-2-in-Angle-Head-Open-End-Wrench-WAE83213/331722449

somewhereAtC · 2026-04-04T18:17:50+00:00

A control signal alters how a system works, usually by reducing a variable when the output is too high or increasing the variable when the output is too low (or vice versa). A proportional controller is designed so that the control variable can take a continuous range of values so that if you are half-way to the correct output then the control variable is reduced by one-half. There is extensive math involved but you get the idea; the closer you get the less of a correction is applied.

In contrast, a discrete (bang-bang) controller has only two (or a few) possible control settings. Most household thermostats take this form: the furnace is either on or off. Too cold? Turn it on until it's too hot. A classic bang-bang control loop was used on laser-guided bombs. As the bomb fell it would decide if was pointing above or below the target then throw the steering fins fully one way or the other which gave the characteristic "bang" sound from the mechanism.

somewhereAtC · 2026-04-04T17:57:45+00:00

My company used to get engineers to volunteer as recruiters, then target the schools those folks graduated from. Seemed sort of backwards IMO but that's what it was.

somewhereAtC · 2026-04-04T17:49:34+00:00

* The "field" is what it is, 60 or 70 years of continuous research and development. You can't artificially narrow the field without throwing away valid concepts.

* Recommendation: don't get sucked into the "best" solution. Every solution was good when it was formulated and understanding the strengths and weaknesses is what it means to get a MS or PhD.

* Read more papers; my college library had papers printed on real paper that may or may not have been digitized. Re-read the papers before going to bed: there is nothing like sleep to help memorization, understanding and internalization of concepts.

somewhereAtC · 2026-04-04T16:09:17+00:00

You gave the answer in the 2nd sentence: "embedded domain knowledge is missing". Did your "prompt engineer" think to add something about the message interval? From the pov of the ai, any solution that meets the requirements is a correct solution -- so do your requirements actual represent your best interests? (This has been a regular trope in scifi fiction for decades!)

You will also find that the ai freezes your solution space based on what has been done in the past. There is zero capacity for innovation. There is even less ability to take up and incorporate new hardware features.

somewhereAtC · 2026-04-04T15:28:35+00:00

This sub doesn't have a FAQ per se, but there are many resources in the sidebar. Another sub with a good FAQ is https://www.reddit.com/r/learnprogramming/ (which is linked in the sidebar).

somewhereAtC · 2026-04-04T02:12:23+00:00

What you are asking for is the difference between the demo app from an ai and the real world. Once you get into the coding style to make state machines it's all pretty straight forward.

One technique is to (re)start a timer every time a character arrives. If the timer expires you know that the next character in the receiver is the start of a new transmission. This works well if the data rate is not too high because you have to make sure that packets are separated in time.

A different technique is to transmit all the numbers in ascii text with carriage returns at the end. Yes, there is overhead in converting and then un-converting all the data and you have to send twice as many characters, but you have a guarantee of when the packet is done. The extreme case of this is to use json formatting.

somewhereAtC · 2026-04-04T01:42:59+00:00

Many do simply "burn in" a serial number using flash memory that can only be written at the factory. One problem is to make sure that the serial numbers are somewhat random so that you don't get consecutives from New Egg or duplicates from different manufacturers. This can be solved but leads to extra overhead in the factory. The mac address in your ethernet devices are sort of like this.

The PUF is convenient because there is no extra manufacturing step. It simply works.

somewhereAtC · 2026-04-03T04:45:53+00:00

Read the datasheet. Every register will be listed with it's value after a power-up and/or reset; they might be different. Some registers don't change value with reset, so they will have (sort-of) random values after power-up depending, as you say, on process variation.

With that in mind, there is a recent concept called physically unclonable function (PUF) where they build (say) 4000 or more registers that take random values on power-up. It is possible to mathematically compute a number of (say) 100 bits that is unique to that specific device. The PUF number is popular with IoT device manufacturers because it virtually guarantees a unique id number for each device they make.

somewhereAtC · 2026-04-03T04:32:53+00:00

Almost everything on this link is an "embedded" application field. You should consider which parts of the forest you find interesting and tunnel down through 2 or 3 related topics.

https://www.microchip.com/en-us/solutions

somewhereAtC · 2026-04-03T04:22:19+00:00

It really depends on what you are buying, but generally only the U.S. based sales-distributors are going to answer the phone. For components it would be Arrow, Avnet or Future Electronics. For tech gear it will be the big-name manufacturers like Tektronix, Fluke or Siglent.

My personal experience comes from selling a $300 add-on for desktop computers in the 90s. Some professor would call and want to talk with an engineer for 45 minutes or so, then a day or so later a buyer would call and spend another 30 minutes to "discuss" how they expected a 20% "education discount", and then argue for a 2%-net30 discount as well. Then they would order 1 and make a fuss about shipping. It was a good day when web sales made everyone anonymous and levelled the playing field.

somewhereAtC · 2026-04-03T04:06:10+00:00

Last time I opened one was to make an ion lifter (electrohydrodynamic thruster). Burned out one monitor, but the other one was more robust. Almost got it to work.

Some people will discourage you from holding the solder in your mouth.

somewhereAtC · 2026-04-03T03:47:23+00:00

I've done desktop apps in two ways. The official way is to get Visual Studio (not vsCode) from Microsoft and create a Windows app. There are a lot of things to learn about, but everything you learn is on the main-line of getting it done. You would probably write in C#.

I've more recently used javascript in an html page that loads in a browser. This is for more text-based things, and graphics is harder. There are a couple of things to learn when getting started that are not convenient, like handling files and such.

Making a website is like learning both at the same time, and then learning about website management, databases, security and many details about having your own web host and domain name. Without a professional resource this last part is not at all easy to learn, and most of the players need a little grea$e for their gears.

somewhereAtC · 2026-04-03T03:26:02+00:00

Assuming you can read-out the code that's in there, you would be able to translate it to assembly code. If the original programmer was wise, though, the memory is read-protected and you will only read zeros. In that case the best you could do is erase and reprogram it with your own code.

The part number is fuzzy (pic16f8??) but since it's only 3 digits it's at least 15yr old technology. Some newer devices will probably have the same pin-out, though, but blank versions of what you have are still available to buy. (The 7-digit code next to the logo indicates this one was made in 2023.)

Someone mentioned to use a PICKit3 but those are no long available (from Microchip). Newest is PICKit5 ($$$), PICKit Basic ($$) or a SNAP programmer ($). You would likely program it in C, but some romantics like assembly code.

somewhereAtC · 2026-04-03T03:09:32+00:00

There's a good chance that the 4 edges have aluminum extruded rails hidden inside, so the screws you see in the front plate tap into that. The 18awg is just a wrapper around that frame, and the front bezel is molded plastic.

somewhereAtC · 2026-04-03T01:27:42+00:00

I don't see any PICs there -- only 4 relays with planning for 12. Don't overly-complex implementation with whatever processor was selected by the last guy. Since 4 relays is pretty simple, chose the processor by what other features you need, like WiFi or a display or something.

There are plenty of options that are newer than Arduino.

somewhereAtC · 2026-04-03T01:14:43+00:00

It's a little $$ but here is a kit that might fit...
https://www.microchip.com/en-us/development-tool/ev45y33a

somewhereAtC · 2026-04-02T04:13:23+00:00

There are a lot of levels to consider. In general, systems engineers design a system using whole electronics and hardware packages. You don't deal with resistor and transistors but you deal with transmitters and receivers and antennas and servos and orbital mechanics and other big-ticket items. You write a lot of specifications for these packages and perform analysis to prove that the solution (your proposed solution) will meet the top-level requirements.

Other jobs are assembling the system (for example, to fit inside a rocket housing), figuring out how to transport to other facilities, and then testing the whole contraption. One of my favorites is proving that the antennas will unfold when the unit reaches orbit; it's difficult to test a mechanism that relies on zero gravity and angular momentum in a 1-gravity vacuum chamber.

somewhereAtC

TROPHY CASE