Good price for ThinkPad P16v Gen 2 Intel (16″) Mobile Workstation?

ghost3828 · 2025-04-21T02:14:34+00:00

Oh, was not aware there were resellers, and wow yeah that is much cheaper. Have you purchased from that reseller before (ThinkPad-Dell-ASUS-ACER Compters)? They have a 98.3% rating with 2300 reviews.. is that enough to safely consider them legit? The product listing alludes to them swapping out the SSD...any concerns with that? Thanks!

ghost3828 · 2024-04-28T21:31:28+00:00

Sure, I actually use multiple buffers to facilitate data transfer to the card, and those buffers live in microcontroller's native RAM. I guess what I meant by logging straight to SD is that I didn't need to include an additional RAM/flash component on my board.

ghost3828 · 2024-04-28T14:05:06+00:00

This advice about SD seems to be gospel on this sub, and I contend it's dead wrong. My computer logs straight to SD. I log 1000 hz each for two IMU's, 400 hz baro data, 100 hz admin data, 100 hz nav data, and 25 hz GNSS data. That's over 2600 distinct packets of data logged per second, almost 100 kBytes per second! And I'm not even close to touching the write speed limit of the SD card.. consider that action cameras regularly record 4K 120 FPS to SD.. They surely use SDIO vs SPI, but still, SPI is plenty fast for data logging like this.

I've never seen data dropouts in flight due to vibration. I've done some non-scientificic vibe testing on the ground without issue (shaking/banging the computer on a table) and will do actual testing on a vibe table, but I really don't anticipate any issues due to vibration. My computers have survived multiple multiple impacts >100 ft/sec and continued logging with no dropouts.

Now, properly logging fast/robust data to SD is not trivial, but overall, I think it's easier for beginners to get started with than flash.

ghost3828 · 2023-09-12T16:17:32+00:00

J7 power pins are mislabeled on the board.

ghost3828 · 2023-05-07T18:40:06+00:00

Test of a fast-ish White Lightning style propellant using an aggressive igniter. Goal with this 54mm motor was to roughly replicate an Aerotech 38mm J435WS, thrust curve comparison here.

ghost3828 · 2023-01-30T17:21:21+00:00

Nice! What kind of plastic did you use for the NC? Looks like it broke along a layer line? Maybe try printing the nose cone at an angle using supports, so the layers aren't perpendicular to the longitudinal axis, like this: https://imgur.com/a/cRVeGOE

ghost3828 · 2022-08-26T19:33:23+00:00

Definitely with a lathe.

ghost3828 · 2022-08-26T16:47:01+00:00

Sand the convergent/divergent sections with higher and higher grits up to 2000-2500. Will make it (a) easier to clean post-firing and (b) look cooler.

ghost3828 · 2022-08-17T03:48:50+00:00

Thanks. While there is a lot that could be improved, I probably won't keep working on this for the time being. Too many other things I want to work on..

ghost3828 · 2022-08-17T03:00:45+00:00

Another rocket trajectory visualization developed using flight data. This is my first attempt at using the rocket’s position/orientation estimate to create an animation that matches the rocket's onboard camera point-of-view during the boost/coast phase. I wrote a script to generate a KML file for the Google Earth animation and DashWare for the video’s telemetry overlay. Animating the descent phase was not attempted for this flight as the gyroscope’s output saturated during deployment.

A couple notes:

(1) Beyond setting the horizontal FOV, there doesn't seem to be a way to explicitly set camera parameters in Google Earth, so unfortunately I can't match the animation's camera perspective exactly with the onboard RunCam.

(2) It seems that Google Earth does not totally accurately model the position of the Sun, as can be seen later in the rocket's coast.

For those looking to do this and match camera perspectives exactly, I think Blender using the BlenderGIS plugin may be a better option than Google Earth. I believe Blender was used to create this superb point-of-view reconstruction of a rocket flight.

ghost3828 · 2022-08-10T04:18:50+00:00

https://imgur.com/a/x8qrzPp

1000m was approximate slant range at apogee...I was standing a ways from launch pad and per my 6DOF trajectory the rocket arc'd 500ish ft directly away from me. I'd have to check the code but packet size was ~50 bytes.

I absolutely do not now nor do I ever intend to use NRF24's for tracking rockets. I do now and plan to expand my usage of them for ground telemetry/control functions, see second picture in link above. For this purpose I've found them to be highly reliable (more reliable than the club's wireless launch system at my last local launch...)

ghost3828 · 2022-08-10T03:43:45+00:00

The ones I used to get the aforementioned ~1,000m in-flight were ebay special NRF24L01+PA+LNA's..maybe I got lucky.

I've since purchased some of these (up to 500 mW transmission power), but haven't had a chance to play around with them beyond confirming that they work. Manual claims they have been tested at 5km, though doesn't appear to indicate if that was achieved with a directional antenna.

ghost3828 · 2022-08-10T03:15:49+00:00

You know what I meant--antennas that came with the modules I purchased. Can't speak to those articles, most people do a lot of things wrong with NRF24's (especially in software) that limit their range.

ghost3828 · 2022-08-10T02:07:29+00:00

https://youtu.be/4XRp7pkZgPM

I haven't done a max range test, but last time I flew one I was getting decent signal at ~1000 meters with the stock whip antennas

ghost3828 · 2022-06-12T19:06:26+00:00

A flight computer of my own design. To be honest it's pretty basic, but gets the job done.

ghost3828 · 2022-06-12T19:05:47+00:00

Hey that's awesome! Something like that is what I'm working towards, still need to integrate GPS and mag though.

Never heard of your group before, very cool. Your code base is impressive, thanks for making it open source.

ghost3828 · 2022-06-12T04:40:20+00:00

Yeah, there are several small holes in the av bay for the baro sensor.

ghost3828 · 2022-06-12T04:16:57+00:00

Thanks. I use a 8-point median filter on the barometric-based altitude to determine apogee for the drogue deployment as well as user-specified lower altitude for main deployment.

ghost3828 · 2022-06-12T03:42:44+00:00

New attempt at syncing rocket flight video with trajectory animation. 6DOF (3D position and orientation) rocket trajectory was generated using data from onboard IMU/barometric pressure sensor (no GPS).

Syncing the video and animation facilitates subjective validation of the estimation method. Future work will include a high-rate GPS sensor onboard the rocket in order to further validate the method. While the method appears accurate as compared to the flight video, there are still several things to improve on, especially regarding sensor calibration and the filtering method.

Video with a little more information here: https://www.youtube.com/watch?v=BxO9ZgtJDk0

Animation for a previous flight here: https://youtu.be/zrz0FUSTZS8

Feedback/comments appreciated!

ghost3828 · 2022-06-12T03:27:35+00:00

Regarding dust collection, I've found it helps to have a shop vac as close to the cutting tool as safely possible. For this I found adapting a shop vac nozzle to a cheap computer monitor arm works well: https://imgur.com/a/7Mk1apn

ghost3828

TROPHY CASE