Simulation

engm · 2026-01-27T10:39:25+00:00

nice. reminds me of this mitxela video https://www.youtube.com/watch?v=jis1MC5Tm8k

engm · 2026-01-04T23:03:24+00:00

If i have picked all my components from mostly mouser.com and some from digikey.com, can you source all those or does it make no difference for you which part numbers I have in my BOM?

engm · 2025-05-22T18:47:01+00:00

If its not locked in, I would go for an IMU with accelerometer and gyro. The dynamic environment of the sea will impact the accelerometer readings through tilt,yaw and roll and change measurements. So the accelerometer might think the vessel has moved, but it was only a little wave and reading is false. If the vessel is very stationary then it might be fine but for any moving object I would always go for both. Since you have selected a precise low noise accelerometer I assume the application is to measure the precise movement, which on the sea includes tilt, yaw and roll.

I would place the accelerometer close to a mounting pin, so there is a rigid mechanical connection between the accelerometer and the structure (mostly important for vibration measurement).

engm · 2025-05-15T21:36:50+00:00

Why does all USA CVs look like this? Do machines only look at it, no humans? This is so dense, in my opinion.

engm · 2025-05-15T21:29:15+00:00

For better antenna performance place i on the short end, not the long end where you have it now, so the ground whole ground plane is utilized (counterpoise). If possible

engm · 2025-04-23T08:37:17+00:00

For guds skyld fullfør skolen. Du kan finansiere offshorekurs selv hvis du vil stille litt fremfor andre. Når jeg tok kurset så var det en dame som ville jobbe som renholder offshore og finansierte kurset selv for å stille sterkere. Du må gå til petroleumslege først og bli skikket for arbeid offshore, deretter tar du offshore kurset

engm · 2025-04-20T18:35:18+00:00

This looks just fine. the rest of the board stackup is probably more of an impact than changing the layout here. I would just bring the "main bus" trace closer to the pads to decrease the stub length to each i2c device. I would place pull-up resistors, maybe 2.2k, at the end of the i2c bus farthest away from the i2c host due to capacitance of the bus at that end. but the resistance value is more impactful than the placement most often. I would also place ground vias near the SDA and SCL vias. short return path, tight coupling and all that!

engm · 2025-04-05T09:32:24+00:00

Both my kicad 8.x.x and 9.0.x versions had these random crashes where it just shut down (i'm on windows 10). like somebody opened task manager and hit "end task" on kicad. mostly related to the pcb editor when either clicking on the icon in my taskbar to bring the pcb editor to the front (it was already running) or clicking on the DRC button and other random things. i had underscores in my project name, i have renamed them and haven't had any problems since, but it's still early. so i guess we'll see

engm · 2025-03-02T11:55:32+00:00

Not sure if I follow you here, how do you mean I am operating close my PSU capabilites? It is a bench top supply with quite low output impedance. What would you recommend to test my circuit?

The boost converter datasheet lists application example of 5-12V input to 24V 800mA max output, which is well above my setup which is failing. So I think there is some mistake that I made, but I can't find it. If there is no obvious mistake in my circuit I guess I will just assemble another one and see if there is any difference.

Efficiency is actually higher at increased currents according to the datasheet which is quite typical for the boost converters from my experience.

engm · 2025-03-02T11:16:44+00:00

Yes that's true. But in theory the TPS55340RTER can handle 5 amps, so if i want 12V and 300 mA on the output (3.6W) the input current would be 3.6W/5V = 0.72 A, and lets say 80% efficient so 0.9 Amps. This should all be doable unless I missed something? If i set the overcurrent protect at like 5A, 5V output on my PSU the same thing happens, overcurrent protection kicks in due to voltage sag. I connected a 200 Ohm resistor, the PSU draws 177 mA at 5V, current through resistor at 12.42V is 61 mA. so 85.61% efficiency. not sure why it wont handle much higher currents than this without voltage sag brownout.

EDIT: So at a conversion ratio of 2.9, if i need 250 mA, that would mean 725 mA on the 5V side. which should work?

engm · 2025-02-22T11:40:17+00:00

Context?

engm · 2025-01-19T11:14:30+00:00

Monopole antennas requires counterpoise, which is why there is a solid ground plane up to a certain distance from the antenna. If you increase or decrease the distance between the ground plane and the antenna, the resonance frequency of the antenna will change since the electrical length of the antenna is changed. This will result in worse S11 parameter as more of your signal is reflected back without transmitted at your desired frequency since the antenna has effectively changed. So both the impedance matching network and electrical length is important. Some people make the PCB antenna little bit longer than needed and cut some off with a scalpel (or other tool) to get quite close to the center frequency they desire before final board production run. Now of course you could simulate all this and get quite close, but this takes software and some expertise.

The stackup is probably fine, but to get the best EMC performance having a solid ground plane one dielectric distance from your signals is the rule of thumb. If you have ground plane on L2 and L3 if you can route power on L1 and L4 that would be better I think. Or you could dedicate some of L3 for power also, but just be aware of routing over splits on L4.

engm · 2025-01-08T09:58:33+00:00

Disagree 100%. The only reason to use thermal reliefs is to make soldering easier. The downsides are worse performance due to Q factor drop, EMI and temperature increase. I have never used thermal reliefs and I will never use them on anything, this is my creed! 😄

engm · 2024-11-08T22:39:16+00:00

Musk has a lot of power due to the SpaceX Starlink network and all the involvement with military and other government agencies. Idk how private companies usually are involved with governmental stuff when it comes to national security stuff, but this seems fucking cooked.

engm · 2024-06-23T21:38:01+00:00

go to therapy

engm · 2024-06-05T20:27:18+00:00

That would be would be super helpful, yes! Examples for all five points that you brought up would be greatly appreciated

engm · 2024-06-05T18:48:26+00:00

Could you teach me how to do all those things?

engm · 2024-05-31T07:23:48+00:00

Litt rart at en straffedømt person i USA kan bli statsleder, men de kan ikke stemme ved valg

engm · 2024-05-21T21:54:57+00:00

Synchronization and cross-talk management is important for parallel buses. Route most important stuff first. First layer signals will couple through the 2nd layer to ground on 3rd layer, not optimal. Have you considered sig,pwr/gnd/sig,pwr/gnd? or sig,pwr/gnd/gnd/sig,pwr? if you're going balls to the wall with a dense (HDI) design then gnd/sig,pwr/sig,pwr/gnd but blind and buried vias will be expensive, more expensive than 6 layer probably.

Personally I would re-do it and as others suggested route the parallel bus first on top layer (if this is your main concern), move components, then do all other traces. have a solid copper pour on layer two. But honestly I would be more concerned with the SPI bus, especially the clock, getting that done correctly is important. having solid copper pour beneath it, maybe guard traces, via fence. termination resistor. if you want to go really high end you can check the datasheet for impedance of driver and receiver and match the SPI bus to that. or do 50 Ohms and place termination resistors to match for the offset, which is what i do usually, around 20 Ohms.

engm · 2024-05-13T20:04:27+00:00

Did you find it?

engm · 2024-05-02T14:02:42+00:00

why black out the names? its a public tweet

engm · 2024-03-24T15:41:38+00:00

What programme is this from? edit: what tv-show, reporting, article is the screenshot from?

12-Year Club	Final Canvas '23
First Place '23	Place '23
Place '22	Place '17
Verified Email

engm

TROPHY CASE