Load Cell Pedal Mod For Fanatec CSL Pedals

I was inspired by rrigby49's mod, but wanted a custom pedal plate and a little better mounting/wiring etc.

Designed to use with m3 Heat inserts on the back of the face-plate, and M3 screws from the back. I printed a blue layer in the middle to make the logos pop a little.

Below is useful info from the linked Remix, I take no credit for it.  They have much better info on how to wire etc, some of the pictures used are their wiring diagrams, I only made a better housing for it, since I am not a  fan of hot glue (although a little glue to hold the boards down isnt a huge issue.

Pieces are separated in 2 so that you can print without overhangs.  I used 5 walls, 5 top and bottom layers and 55% infill.

Here are the parts I used:

4x50kg load cell kit with HX711 amp module - https://smile.amazon.com/gp/product/B086ZHXNJH
Each module can handle 50kg to this kit could actually support up to 200kg of force.

IMPORTANT - The Arduino used must be either a Pro Micro or Leonardo. Only the ATmega32U4 Arduinos support USB HID to be seen by the OS as a USB game controller.
Arduino Pro Micro - https://smile.amazon.com/dp/B08BJTS2N8

Here is the Arduino code: https://pastebin.com/QEseWrLE

I used a USB-C Pro Micro because I like USB-C, there are micro-usb versions as well. 

To change brake pressure, adjust the "calibration_factor" variable at the top of the Arduino code until the Fanatec brake and the Arduino brake are very similar in range when the brake pedal is fully depressed and voilà, virtually no getting used to the new brake pedal as you just set them to have a very similar load cell pressure vs pedal movement range

HX711 80hz mod.  Definitely do this, otherwise your brake input will be noticeably laggy, and have “steps” if you are using any form of visualisation, instead of being smooth.

1. Ok this is probably the hardest step so be careful. On the HX711 board pin 15 needs to be lifted from its contact pad which is ground. Then it needs to be bridged to the neighboring pin 16. If pin15 on the HX711 board is low it runs in 10hz mode which causes the pedals to react too slowly so we’re disconnecting it from ground and bridging it to pin 16 which is high. Some boards have easier ways to do this as can be seen here: XFW-HX711 80Hz mode - Using Arduino / General Electronics - Arduino Forum but I’m only familiar with the method I used. Check my “HX711 10hz to 80hz mod” photo. If you have very little experience with a soldering iron, you might find it easier to use a really pointy pair of flush cutters to cut pin 15, bend it upwards with a razor blade, and then solder it to pin 16, but as with the other boards I didn’t do this so I’m not sure how well it would work. They might just not be pointy enough to make a suitable cut.