Working Arious motion tracker

Working motion tracker from the video game Alien: Isolation

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This motion tracker is not a 100% replica, it contains deviations which are necessary for it to function properly. The motion tracker from the video game is much more practical to build that the one from the movies, so its easier to build.

By using an array of multiplexed Doppler radar modules motion can be registered and the direction can be extrapolated. Distance cannot be measured, but signal intensity can, and by knowing the object size, distance can be approximated from the signal amplitude.
Once the signals are processed, a dot can be displayed on the screen and instead of distance in meters, the distance is represented in decibels which show the received signal intensity.
Additional processing is required to cancel out the motion of the device itself and detect only objects moving relative to the background.

This project was inspired by the 2017 sci-fi contest, so everything here was created from scratch and posted as a contest entry.

GNU GPL license

To match the style of the device shown in the movie/games modern components were avoided where possible, which made things a bit more difficult. The only components where this project cheats is the LCD module instead of a CRT, and accelerometer and magenetometer modules.
To power the device, 8x AA batteries are required. The device supports NiCd rechargeable batteries, NiMH will not charge properly with the included charging circuit.
In this project its stated that it uses the HB100 module which actually is not true, the modules being used are Chinese clones which work just fine.
It is actually not possible to purchase the HB100 modules from websites like Mouser, there seems to be a restriction which prevents them from being exported ??? (at least to Croatia)

Main components:
- Max 8 Doppler radar modules
- PIC18F series MCU
- 4.3" TFT LCD SSD1963
- External A/D and D/A converters
- Accelerometer and magnetometer mdoules
- SAA1099 sound chip
- MAX232
- Rechargable batteries

Project members & tasks:
Dajgoro - Electronics & firmware
Lovro - 3D modeling & mechanical
Ante - Logistics & QA


KiCad footprint for the 4.3" TFT LCD SSD1963 module for those who wish to use it for another project. Pins are set so that it matches the regular dual row pin header component. Example link:

kicad_mod - 6.37 kB - 03/07/2017 at 00:15


KiCad project of the main board (gerbers included).

Zip Archive - 766.55 kB - 03/06/2017 at 23:57


Arious main board v1.2.pdf

Main board schematic v1.2.

Adobe Portable Document Format - 226.50 kB - 03/06/2017 at 02:24

Preview Download


Thoughts on how the processing algorithm might work.

plain - 1.48 kB - 03/06/2017 at 02:21


KiCad project for the HB100 preamplifier module, along with the gerber files (updated).

Zip Archive - 171.44 kB - 02/28/2017 at 23:25



LTspice simulation of a custom charging circuit designed for this project that is able to charge NiCd or NiMh batteries and indicate when its done charging. Also there is a low drop linear voltage regulator that can provide 6V for the analog circuits even if the battery voltage drops as low as 7V.

asc - 4.56 kB - 02/17/2017 at 02:20


HB100 preamplifier.pdf

PDF of the HB100 preamplifier scheamtic.

Adobe Portable Document Format - 47.14 kB - 02/17/2017 at 00:12

Preview Download


Slightly modified LTspice schematic/sim of the preamp found in the HB100 application note.

asc - 2.62 kB - 02/12/2017 at 19:16


View all 8 files

  • 5 × HB100 module Doppler radar module
  • 1 × 4.8" 320x480 TFT LCD TFT LCD display
  • 1 × PIC18F4550 Microprocessors, Microcontrollers, DSPs / Microcontrollers (MCUs)
  • 1 × SAA1099 Programmable Sound Generator IC
  • 1 × MPC3208 Data Converters / Analog to Digital Converter ICs (ADCs)
  • 1 × CD4051 Electronic Components / Misc. Electronic Components
  • 5 × TL074 Amplifier and Linear ICs / Operational Amplifiers
  • 10 × BC547 Discrete Semiconductors / Transistors, MOSFETs, FETs, IGBTs
  • 4 × 2N2222 Discrete Semiconductors / Transistors, MOSFETs, FETs, IGBTs
  • 1 × BC560 Discrete Semiconductors / Transistors, MOSFETs, FETs, IGBTs

View all 31 components

  • Quick update #5

    Lovro Dujnić03/14/2017 at 21:21 0 comments

    3D printer is still at hold, we are waiting for other PLA material so in the meantime we are working on part design. When we finish and test all parts, we will publish all models to be ready to print. Handle is standard bicycle size so you can put standard bike handle on it. Right side of mainboard box is without any holes because we want to leave option for any kind of switch to be installed on to it also as rectangular fuses. Main parts assembly chart can be seen below.

  • Quick update #4

    DL10103/08/2017 at 01:29 0 comments

    We already got most of the parts for the main board from TME, except that they didn't have some of the IC we needed, those will have to be sourced from ebay. /:

    Due to limited PCB space the fuse holder has been removed from the PCB and will have to be installed on the chassis instead, the five bumps on the right side of the screen might be replaced with fuse holders.

    The next update about the electronic part should be when we receive the PCBs which might take a while to arrive..

  • Case redesign

    Lovro Dujnić03/06/2017 at 17:52 0 comments

    We had to redesign entire case and part placements in order to get rid signal attenuation that was caused by PLA plastic. Now the radar antennas are exposed to outside environment in order to increase sensitivity of radar modules. Covering holes with non-conductive materials like teflon is also an option so the case matches in looks of the thing in the game. We have some problems with new PLA filament we bought so let's hope that we will fix that ASAP. How it looks now? See below.


  • Mainboard routing completed

    DL10103/06/2017 at 02:21 0 comments

    After I was able to test two radar modules simultaneously and confirming that at least two can work without interfering I modified the main board schematic to allow multiple modules working simultaneously.
    Once the schematic was done, I routed the board, project files can be found above.
    The main board PCB mounts directly under the LCD, pin header connector is visible on the left side.

    Also, I wrote a little text file with thoughts on how the processing algorithm should work, I will have to wait to get the main board pcb done before I can test anything.

    *Board has been updated since this picture was uploaded

    Since the old 3D model is not valid anymore, what managed to be printed will mostly have to be scrapped, new model is not yet finished.

  • Radar preamp modules completed

    DL10103/05/2017 at 01:17 0 comments

    Today (5.3.2017) I finished soldering the individual radar module preamp boards (one extra just in case).

    So now I was able to test how two modules interact when powered simultaneously.
    To be safe I assumed they would interfere each other, but now when I can actually test them I see that they can actually run in parallel.
    Since they can be tuned with the screw on the metal shield there can be a big enough difference in frequency for them not to interfere with each other anymore. When looking at the output spectrum from the previous log its visible that the output spectrum (harmonics aside) is very narrow.
    This is also means now I can update the mainboard schematic so that it can activate multiple modules simultaneously instead of just one at the time, allowing for a much more responsive scan.

    Here is the picture of the output signal when both are working and me waving my hand:

  • RF test

    DL10103/01/2017 at 22:57 0 comments

    I managed to get some measurements done at the RF department of the local university. We took a look of the output RF spectrum, and did a simple range test. While measuring the output spectrum I changed the supply voltage of the radar module to see how the output frequency changes and here are the results:

    4V - 10578.702 MHz
    4.5V - 10578.502 MHz
    4.75V - 10578.612 MHz
    5V - 10579.020 MHz
    5.25V - 10579.348 MHz

    This show that changing the voltage from 4.5V to 5V gives about 500kHz of frequency shift which can be used for FMCM operation.

    Range test showed that its works up to 20m, but due to noise I would say it works reasonably well up to 15m.

    Test setup:




    Person walking towards from a distance of about 15m, radar module is on the left behind the metal sheet, so it does not register the oscilloscope operator/cameraman.

  • Preamp boards

    DL10102/28/2017 at 23:19 4 comments

    The preamp PCB-s have arrived today(28.2.2017), the components had already came the day before so I was able to solder a board and see how it works. At first it did not work as well because I had set some wrong resistor values for the voltage settings, which I fixed and now updated the project files. Now it works reasonably well, it can detect motion reasonably well all across the apartment length (have yet to get a meter and do a proper range test).

    On the image below it detects motion as the picture is being taken from just me waving the hand a bit behind the camera.

    The boards are Seegson branded, bit of Sevastopol/Sevastolink station tech.

  • Quick update #3

    DL10102/23/2017 at 20:13 0 comments

    - The new plan for the radar module placement is to put two of the angled (looking at 45 deg) on the slopes behind the display, and the other three (looking left, right and forward) in the upper back compartment so that cutouts can be made to expose the antenna pads. Batteries and speaker would sit in the lower back compartment and the electronics could be right behind the display.
    - Preamp PCB-s have been shipped and are on the way.

  • Signal attenuation test

    DL10102/22/2017 at 00:27 0 comments

    We made a quick test as to see how much signal attenuation is there when the radar module is enclosed with the 3D printed plastic since the issue was mentioned in the comments below.
    The current configuration seems to be problematic, so changes will have to be made. One option is moving the radar modules in the lower compartment and having cutouts where the patch antenna are located.
    Video demonstrating the issue:

  • Quick update #2

    DL10102/21/2017 at 20:44 0 comments

    - Minor changes to the mainboard schmeatics.
    - We got different kinds of paint and started experimenting to see how can we match the exterior texture
    - 3D printing is still ongoing

View all 17 project logs

View all instructions

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AKA the A wrote 02/17/2017 at 12:07 point

One question - have you tried how the plastic wall of the box affect the signal from the module? At 10GHz, a lot of material (including plastics) behave differently...

As for modulating the frequency - it's dependent on the current going through the device. Modulate the power input and the output should be modulated as well.

  Are you sure? yes | no

DL101 wrote 02/17/2017 at 12:54 point

I don't really know how the plastic will react, but its the only kind of housing I can afford to make. If it will be an issue I'll have to cut holes and cover them with paper or something.

Regarding the frequency, as I wrote below on another reply, I won't be doing that for now before I get the simpler version working, tho the preamp module I designed has its own little regulator for the radar module, so modulating the power supply would just be a matter of tapping the regulators voltage reference. I even set an enable signal which directly affects that, so I might not need any hacking at all to perform that. I might build in such an option in the hardware and let it sit there until I get arround fiddling with it later.

  Are you sure? yes | no

Martin wrote 02/17/2017 at 14:11 point

Paper would not be that good, especially if it has any chance to absorb moisture. If the plastic of your housing really absorbs too much of the RF energy then try polystyrol, polyethylene or teflon. These have really good RF performance (low losses).

Btw.: I just saw, that you plan to use BC109C. You can just use the more modern cheaper BC549C or BC550C just what is more easy to get.

  Are you sure? yes | no

DL101 wrote 02/17/2017 at 14:59 point

"try polystyrol"
Thanks for the advice.

"Btw.: I just saw, that you plan to use BC109C. You can just use the more modern cheaper BC549C or BC550C just what is more easy to get."
That was just an Easter egg, wondering if anyone will notice. :D
I will use either the BC5xx or the 2N2222.

  Are you sure? yes | no

DL101 wrote 02/22/2017 at 00:58 point

The plastic is bit of an issue after all, will have to rearrange the modules and add cutouts.

  Are you sure? yes | no

Martin wrote 02/16/2017 at 09:43 point

You write that the detection of distance is not possible. It would be if you can somehow modulate the frequency of the module to some extent, ideally with a triangle waveform. Sinusoidal is also possible, but it is more difficult to evaluate the signal. (FMCW radar principle) Perhaps it is possible to do this with some variation of the supply voltage. Then you get output signals even for a motionless object, the frequency is dependent on the distance. If the object is moving you get different frequencies during the rising and falling portion of your modulation signal. Now the some of the two frequencies gives you the distance and the difference the speed.

  Are you sure? yes | no

DL101 wrote 02/16/2017 at 12:58 point

The HB100 module uses oscillator which is physically tuned with a dielectric pellet and traces which match the oscillator wavelength.
In a further iteration it could be possible to create a voltage controlled oscillator and maybe use one of those integrated RF amps to boost the signal and create a array of receiver antennas which would all sync up with the main oscillator instead of multiplexing individual radar modules. Something like this might work:

  Are you sure? yes | no

Martin wrote 02/17/2017 at 12:20 point

I know it is a DRO, but you can even pull (modulate) a crystal oscillator and a crystal has a much higher Q than a DR pellet. So it should be possible.

With not to much inaccuracy you could call the DRO pellet a glorified ceramic capacitor. :-) Normally they are factory tuned by a grounded thick screw, like a worm screw which is placed above the pellet at a distance of some 0,1mm. So at least some mechanical tuning should work, if you place a grounded slug above the pellet on a piezo speaker. Perhaps even a piezo disc from a buzzer alone would work. I don't know the tuning sensitivity (Hz/µm).

In theorie a small plate or metal ring connected to a varicap diode could also work.

This sure requires some experimentation (or research about tuning DRO's), but that truly would qualify as a hack. :-)

Building a phased array antenna instead of individual modules would of course be a great achievement but require good in depth RF/microwave design knowledge and simulation tools. I don't know your technical background.

  Are you sure? yes | no

DL101 wrote 02/17/2017 at 12:50 point

For start I'll keep this thing simple, its complex enough as it is.
For now I just want to be able to measure the amplitude and angle of incoming signals. Once I have that working I can work on the next version.
Another problem that needs solving is the motion of the device itself, all signals will have to go over the FFT so that the motion of the device can be cancelled.

As for doing the custom device, I am not an RF wizzard, but I would love to try doing something like that. I do have a friend who works at the local uni in the RF lab and he has access to all of the fancy tools and gears for doing such things.

  Are you sure? yes | no

AKA the A wrote 02/17/2017 at 12:03 point

It (at least theoretically) is possible to get distance measurements from a doppler device... you need at least 2 of them, fairly far apart and the object (or detector) has to be moving. Then it's just slightly more complicated goniometry, that should be capable of providing speed and angle, from consecutive measurements you should be able to count distance.

  Are you sure? yes | no

DL101 wrote 02/17/2017 at 15:01 point

Oh, thanks!
I'll give it a read.

  Are you sure? yes | no

Ianmcmill wrote 02/12/2017 at 12:57 point

I did some research on those radar modules and I stumbled over a blog article from 2013 where the guy is showing an amplifier for the HB100. The schematics are open source. He also offers ready made pcbs but they are rather expensive compared to the 3€ radar module.$7-USD-doppler-motion-sensor

  Are you sure? yes | no

DL101 wrote 02/12/2017 at 13:19 point

Thanks for the link. The HB100 datasheet also has such schematics.
The pcb-s are not an issue, I will design my own and order them soon.

  Are you sure? yes | no

Martin wrote 02/17/2017 at 12:54 point

I don't think this circuit at "limpkin" is a good solution. What you want is a very low noise AC amplifier. You do not even need a very defined gain, as you are only interested in the frequency. So an Opamp, especially a rail to rail Opamp is not a good part for this task. Rail to rail amplifiers are normally a compromise per se and OpAmps normally produce more noise.

This is a high speed low distrotion OpAmp (50MHz GBW) for a task needing only a GBW of greater 7kHz. Ampflification of 100 with an upper frequency limit of 72Hz. This high bandwidth increases noise completely unnecessary and makes it expensive.

The amplifier has a quite good noise voltage performance of 4,5nV/SQRT(Hz) but at 100kHz. In the interesting frequency range (10 to 70Hz) it has 50 to 100nV/SQRT(Hz). And the circuit is of quite high impedance to be low noise. 

By the way the symbol of the double OpAmp in the circuit at "Limpkin" is the worst example of such I have ever seen. It is just confusing. Either you have a block symbol of the IC with its pins in the physical layout of the package or you use two individual triangular symbols.

I would use 2 or 3 single low noise transistor stages, AC coupled and also AC couple the input of the comparator. I would probably design the first stage with a gain of 100 and 2 more stages with a gain of 10 to enable higher output swing. But it can be also possible that you can use just two *100 stages. With an RC combination in parallel to the emitter resistor you can adjust the frequency response (filter curve).

You can also use a good low noise microphone amplifier, if you want to use an IC.

  Are you sure? yes | no

DL101 wrote 02/17/2017 at 15:10 point

I already designed and ordered the amplifier board which is based upon the application note schematic. I will build it and test how it performs.
This is just to have something better than what I have now which is just two bjt-s. Those ended up being bit too noisy. In the next iteration I'll be getting a better opamp and building it all with smd. This first revision of the entire device will be a bit crude, but should be good enough for proving the concept. Also the next model might get a design overhauld, not having to stick with the game prop hosuing.

  Are you sure? yes | no

Ianmcmill wrote 02/11/2017 at 22:49 point

A really cool project. It would be really nice to see the radar setup and it's results!

How about a PiZero?

Thumbs up on this project!!

  Are you sure? yes | no

DL101 wrote 02/11/2017 at 22:52 point

Sure, we(me and my friends) are still putting together a list of parts to order, unfortunately things take a month to arrive from china, so before than the project is stuck only with the one radar module i had from before. If all goes to plan the housing should finish printing in a week.

PiZero could work, but its not necessary. It only needs to draw a static image for bacground, and everything else is just math.

  Are you sure? yes | no

Ianmcmill wrote 02/11/2017 at 23:00 point

Ok, cool. I am not very into coding and UI stuff on Arduinos and TFTs. I know there is the utft library for Arduino which is capable of the stuff needed for this project. Albeit a PiZero might be overpowered, it has the capability to do some nifty screen effects like blur/motion blur. :) And throwing some cool linux boot code onto the screen which could be modified with Wayland Corp. stuff.

  Are you sure? yes | no

DL101 wrote 02/12/2017 at 00:01 point

I won't be using an arduino, I rarely use it. The graphic is rather simple, it consists of straight lines and circular sections, none of those are hard to generate. If I wanted a fancy background I could just draw an image on the PC and turn it into raw RGB data and load it into an flash/eeprom.
As for Wayland Corp, this model is manufactured by Seegson, the competitor company. :D
*Edit: Not actually made by Seegson, only the station was made by Seegson

  Are you sure? yes | no

Ianmcmill wrote 02/12/2017 at 11:38 point

Seegson. Right. I need to do my homework more carefully :)
How long is the range of those doppler radars?

And I would love to print the model already. Did you design it yourself or where did you get it from?

  Are you sure? yes | no

DL101 wrote 02/12/2017 at 12:35 point

The Doppler modules are HB100, and the datasheet says it can detect human walking at range of 15 meters, the ebay sellers claim 20 meters, so its something in that figure. The device from the movies has the same range.
So far I only built a small amplifier with two discrete bjt transistors, and that has lots of noise which limits the range to about 5 meters.
The 3D model is being designed by a friend who is involved in the project (gotta yet to open a account), and its not done yet. Once the design is completed, it will be uploaded here, along with everything else.

  Are you sure? yes | no

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