You will need the following (prices as of 7/24/2022):

1 Arduino Zero $47.40 https://store-usa.arduino.cc/products/arduino-zero

1 Tundra Labs HDK $149.99 https://tundra-labs.com/products/steamvr-tracking-general-purpose-hdk-reference-design-tl448k6d-gp-hdk?variant=39421903536337

1 Dualshock 4 Controller $59.00 https://www.walmart.com/ip/Sony-PS4-DualShock-4-Wireless-Controller-Jet-Black/28802345?fulfillmentIntent=In-store

1 HTC VIVE system $379.95 https://www.ebay.com/itm/115462668469?epid=24031083110&hash=item1ae21c80b5%3Ag%3AFZ8AAOSwC2FizbrK&LH_BIN=1

1 Adafruit 50 pin 0.5mm pitch FPC Adapter $2.95 https://www.adafruit.com/product/1492?gclid=Cj0KCQjw2_OWBhDqARIsAAUNTTGFtP9uOp4txL4VB3iM2fRCx-2gsc8LQW7-TXvh53Q7n8jvxHMquWIaAhxuEALw_wcB

1 25pin connector $2.41 https://www.mouser.com/ProductDetail/Omron-Electronics/XF3M-2515-1B?qs=%2F9jDaHz9Z2hfWPSUJy%252Bmsw%3D%3D

1 Micro USB to Micro USB cable $7.39 https://www.officedepot.com/a/products/143927/StarTechcom-8in-USB-OTG-Cable-Micro/?utm_source=google&utm_medium=cpc&mediacampaignid=71700000096441899_17451447826&gclid=Cj0KCQjw2_OWBhDqARIsAAUNTTEJUSkQPUrMOsTOX9NnBlPmykRN8yS3RmoqbBmp-oehMveUyCBKDH8aAu6IEALw_wcB&gclsrc=aw.ds

1 USB to USB-C Cable $7.48 https://www.amazon.com/Samsung-Braided-Charging-Durable-Compatible/dp/B07C97XFRL/ref=sxin_17?asc_contentid=amzn1.osa.354faebc-5d4e-4a11-8318-efc43f8312b5.ATVPDKIKX0DER.en_US&asc_contenttype=article&ascsubtag=amzn1.osa.354faebc-5d4e-4a11-8318-efc43f8312b5.ATVPDKIKX0DER.en_US&content-id=amzn1.sym.15d473d8-31ee-48d9-a207-aaa8ce868fca%3Aamzn1.sym.15d473d8-31ee-48d9-a207-aaa8ce868fca&creativeASIN=B07C97XFRL&crid=38WH410ZPYXHS&cv_ct_cx=usb+c+cable&cv_ct_id=amzn1.osa.354faebc-5d4e-4a11-8318-efc43f8312b5.ATVPDKIKX0DER.en_US&cv_ct_pg=search&cv_ct_we=asin&cv_ct_wn=osp-single-source-earns-comm&keywords=usb+c+cable&linkCode=oas&pd_rd_i=B07C97XFRL&pd_rd_r=b832dac4-4121-4fec-b41a-e89b6a027f33&pd_rd_w=KZ71W&pd_rd_wg=4Jooz&pf_rd_p=15d473d8-31ee-48d9-a207-aaa8ce868fca&pf_rd_r=1KBE9YZ1DPQ5VBZ8X4E6&qid=1658698389&sprefix=usb+c+cable%2Caps%2C123&sr=1-1-071eec3b-aca5-449e-bbff-36c3e2e2e9e2&tag=gamerevolution-tca-20

1 Micro USB cable capable of charging $4.79 https://www.amazon.com/Micro-USB-to-Cable/dp/B004GETLY2

1 Battery Pack $25.99 https://www.amazon.com/Anker-PowerCore-Ultra-Compact-High-Speed-Technology/dp/B0194WDVHI/ref=sr_1_18?keywords=usb+battery+pack&qid=1658698571&sr=8-18

1 Basic Soldering Kit $19.99 https://www.amazon.com/Soldering-Adjustable-Temperature-Multimeter-Desoldering/dp/B09VXQ221K/ref=asc_df_B09VXQ221K/?tag=hyprod-20&linkCode=df0&hvadid=564798416375&hvpos=&hvnetw=g&hvrand=5931988270728837608&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9019122&hvtargid=pla-1654365861245&psc=1

1 Hot Glue Gun $5.67 https://www.walmart.com/ip/AdTech-Full-Size-High-Temperature-Select-Hot-Glue-Gun/17404364

1 Order a 3D print of the CIA model from place like https://www.hubs.com/3d-printing/

1 Computer capable of powering virtual reality $700 or more - see guide here (need a keyboard, mouse & monitor as well) https://techguided.com/vr-ready-pc-builds/

1 Steam account with SteamVR HDK permissions $Free

Download and Install Arduino IDE with SAMD package of Arduino Zero 1.8.2 VERRY IMPORTANT as the other version of the package don't work.

Also download the PS4 SAMD master folder from the github and place your Arduino library https://github.com/felis/USB_Host_Shield_2.0

Download and and install SteamVR - make sure to opt-in to the SteamVR Beta

Download and Install SteamVR HDK

Additionally go to the project page and download CIA.zip and Driver.zip

Once things have arrived go ahead and get things ready!

Make sure the HTC VIVE system works on the computer. 

Test the Arduino zero by using the "blink.ino" file

Charge the Battery pack.

Charge the PS4 Controller.

Solder the 25pin FPC onto the Adafruit adapter.

Open the CIA. zip file or look at Input tracker video.

Wire the arduino zero to the adafruit adapter as outlined at the start of the CIA.ino file or in the video.

To upload the Arduino program to the Arduino Zero you need to export the CIA.zip file. The files from the zip folder need to be in a regular folder name "CIA". Then you need to open Arduino and upload the code to the programming port of the Arduino zero

This part is tricky because I'm not sure what I'm allowed to say.

The STeamVR Tracking HDK has a lot of documentation is pretty straight forward.

Basically I give you the CIA.stl file, a model. You then need to place the tracker locations on the device using the SteamVR Tracking HDK and export those locations into a Json file. Then use a hotglue gun to glue the Tundra Labs HDK and sensors onto the CIA model as you had made the device be in the SteamVR Tracking HDK.

As an alternative you can try to hot glue things as close to what I have - flash the json file on the the TundraLabs and see how it tracks. 

You may also need to run the IMU calibration of the device as each IMU is slightly different.

Now that you've programmed the Arduino, uploaded the json files,  got the device tracking and sending inputs its time!

Connect the USB cords to the device as shown in the image gallery.

Enjoy using the PS4/Dualshock4 Controller in SteamVR!