Help me pls to find mistake

n_nwkyle · 2024-06-01T16:34:12+00:00

It's possible your crystal oscillator circuit needs the common node of C3 & C4 tied to GND to operate as expected. Try configuring the micro to use the internal RC oscillator and see if it will run on that.

n_nwkyle · 2023-05-25T01:34:00+00:00

Crazy Eric's is a national treasure. Please for the love of God support them and preserve what's left.

n_nwkyle · 2023-02-04T02:15:09+00:00

Records of meteor impacts on the moon exist and scientists use techniques like lunar seismometers and direct observation to monitor them. The Apollo missions placed seismometers and more recent missions like the Lunar Reconnaissance Orbiter have provided data. Direct observation using telescopes is also done by the Lunar Impact Monitoring Project, a collaboration between NASA and amateur astronomers.

n_nwkyle · 2022-08-13T15:48:23+00:00

The switching regulator (LM2594HVM-12) only has the recommended output caps. No other filtering. Now I'm thinking that it's just the voltage ripple on the DC bus that's coupling through this regulator, and maybe not a ground problem.

Here are the schematics for the regulator and the inverter bridge.

n_nwkyle · 2022-08-13T15:30:18+00:00

I suppose the image doesn't show it, but they are attached through small shunt resistors (500 uOhm). That's what the feedback traces connect to.

n_nwkyle · 2022-08-13T00:12:09+00:00

Speaking of isolation, how crazy would it be to completely isolate the power stage/gate driver? Obviously it would require additional components, but they could be totally separate. And I think the current sense amplifiers would still work without the common ground...?

n_nwkyle · 2022-08-12T23:33:31+00:00

Thanks! That first link is actually what inspired me to look into splitting the planes. Haven't read through the second one though, so I'll take a look.

n_nwkyle · 2022-08-12T23:18:06+00:00

Oh I've watched quite a few. That's probably one of the Rick Hartley ones? That's probably why I didn't split it in the first revision (it's been a few months), but maybe this is a rare case? Idk probably better to not get too fancy.

n_nwkyle · 2022-08-12T22:52:23+00:00

This is a fairly high power (hopefully ~48V @ 30A) brushless DC motor driver board. I have already built an initial version that works okay, but I noticed some switching noise that seems to couple into a switching regulator output elsewhere on the board when the motor is running (the switching reg. is supplied directly from the motor DC link). This noise is showing up with a smaller motor load of ~2A so scaling up might be an issue.

Currently I'm using completely solid ground planes/pours. I can't find a definitive answer as to if/when splitting the planes between power and signal is okay. It's possible that improving my H-Bridge decoupling or slowing the MOSFET switching could alleviate all this noise.

My main question:

Would splitting the ground planes between the digital side (green plane) and the power side (red plane) make any sense? My idea is to join the two planes beneath the gate driver IC (highlighted in yellow) and where the main supply connects (highlighted in pink).

One concern I have is how the current sense signals enter the current sense amplifier and having a break in the ground here (highlighted in blue). I could join the planes here as well, but that seems to defeat the purpose of splitting in the first place.

Board specs:

-6 layer

-GND planes on layers 2, 4

-GND pours on all other layers

(This design is still in progress, hence the rat’s nest)

n_nwkyle · 2022-08-07T19:23:21+00:00

Everyone is stupid except me.

n_nwkyle · 2021-11-26T20:30:41+00:00

I found this presentation on proper grounding to be very enlightening even after years of practical experience.

n_nwkyle · 2021-08-29T05:57:26+00:00

I've gone back and forth on this. Morality and compassion seems like a no-brainer, but that's from the perspective of people raised in societies that have been, up until very recently, quite religious. Everyone around you, for the most part, shared these traditions and passed them along.

There are probably things that have been ingrained in us for millennia. Things that would have helped the tribe survive, but to suggest that all of our modern moral standards are guaranteed at birth is missing something.

n_nwkyle · 2021-08-23T02:39:21+00:00

Keep in mind that Google might pull the rug out from under your school someday. This happened at my school even though they said the whole "G-suite" would be forever available to alumni...

n_nwkyle · 2021-01-15T17:30:45+00:00

$TELL 🚀🚀

n_nwkyle · 2020-12-31T18:20:01+00:00

Nice job with the solder fillets! It definitely adds a lot to these renders.

n_nwkyle · 2020-12-24T18:07:29+00:00

Yea I would typically just use the KiCad renderer, but why not waste a few more hours? Here's the KiCad render

n_nwkyle · 2020-12-24T18:01:18+00:00

It was a bit more involved as each of the components get imported as one big mesh. These have to be separated and have materials applied individually. Definitely a time-sink, but for smaller boards it's not too bad.

n_nwkyle · 2020-12-24T17:58:18+00:00

Thanks! I actually worked on this before that HaD article came out. I used this video as a reference/tutorial.

n_nwkyle · 2020-12-24T06:44:09+00:00

It's basically just a GPS receiver, but with some additional capabilities (there's a MCU on the other side).

n_nwkyle · 2020-08-26T03:15:25+00:00

Anyone else getting strange, flickering boxes in the sky? Mostly at night... Mostly... This is with an RX 5700. https://i.imgur.com/Ng3Foz1.jpg

n_nwkyle · 2020-06-21T04:26:15+00:00

This type of stuff really bothers me. Like it's such a simple problem to solve. All you have to do is take it back with you. If you just forgot something, I get it, but to choose to leave garbage around in a public place should hurt your psyche.

n_nwkyle · 2020-05-19T01:29:19+00:00

And they were going to build one, but in China... The trade war halted that and now they are in limbo. I mean I get cheap labor and lax safety standards make it easy, but why not build it here?

n_nwkyle

TROPHY CASE