A few weeks ago, users necronom and punkmarine posted this thread with the videos of the working (really working!) Aliens Motion Tracker made by RobSmithDev, with the DreamHAT+ radar module to detect motion up to (theoretically) 15m.
I immediately knew I needed to build one as well. But of course, I had to tailor make it for my own "Motion Tracker needs" and will therefore have to heavily modify my build.
Notable differences that will govern my build:
1. All real (found) parts Motion Tracker
I gathered all the parts years ago, and even got quite far with my assembly, but was searching for years for the right electronics kit. RobSmithDev has made this dream come through, but he used a 3D printed tracker. That means I will need to do loads of modifications, since the real parts tracker (especially the Kango drill) will need to be dremeled out to create the necessary space, and the electronic parts rearranged to fit my version. Luckily, there is already a user pioneering a real parts build on RobSmithDev‘s discord which I might use for inspiration, at least as long as it fits my vision of my tracker.
2. Position of the radar module
After rewatching the movie, I noticed that the Colonial Marines make it a point that the Motion Tracker needs to be held „downwards“ when tracking, i.e. with the Kango grip not towards the user, but towards the ceiling. RobSmithDev put the radar module at the „front“ on his build, but I want to put it at the „top“ of the Tracker, so that it detects the way it does in the movie.
3. Detection range
RobSmithDev seems to have gotten a lot out of the radar module, but I’ve been pouring over the code and the datasheets and had a few ideas to try and extend range. Contrary to what RobSmithDev states in his second video, the two lines on the Tracker display don‘t seem to correspond to 5m and 10m in the movie, but rather 10m and 20m, or even more. While it is unrealistic that such a range can be achieved with the Dreamhat radar module, I believe the advertised 15m instead of only slightly over 10m might be well within the realm of possible, with tightening the bandwidth and a few other tricks.
4. Accurate sounds
RobSmithDev has the Raspberry Pi synthesize the sounds. While this does in theory seem better and likely faster than using sound files, the ping sounds in the videos don‘t quite grab me the right way. Of course, this might be the video or the small speaker size, but it‘s something I‘d like to look into once I get to that stage.
So stay tuned, I only just got some of the electronics in and retrieved my tracker parts from storage. This is not going to be a quick build, since my job doesn‘t leave me with much free time, and I want to get this right to be my „be all, end all“ Tracker build.
And many many many thanks go out to RobSmithDev and his great videos! I haven't been this excited about the Aliens Motion Tracker in quite a while!
Cheers!
Roman