Thrustmaster T3PA DIY Loadcell mod (T300, T500) < 10$ by Kookaburra88

Last crawled date: 3 years, 1 month ago

Introduction
This is how you can add a loadcell to your T3PA pedals and thus improve the brake fell in your favorite racing simulation.
Requirements
What you need:
Thrustmaster T3PA pedals
Aruduino Pro Micro(~4$) (Arduino Micro, Due or Leonardo should also be possible) link
Loadcell (~2$) link.
HX711 breadbord with adjustable framerate (~2$) link
some cables
2xM5x12 bolts
1xM5 nut
Instructions:
Remove the conical brake mod from your T3PA pedals
Print the brakeMod_part2.stl (loadcell holder)
Mount the loadcell to the printed loadcell holder using the two M5 bolts
Insert the M5 nut into the loadcell holder
Mount the loadcell holder to your T3PA pedals using the original M5 bolt from the conical brake mod
Attach conical rubber to loadcellOption 1:
Cut out a piece of aluminum/stell where you can mount the conical rubber on and screw it onto the loadcell, see images.Option 2:
Drill a 8mm hole throuh the inner M4 hole and cut a M10 threat through that hole. Screw the conical rubber directly to the loadcell. You may also want to use the circlip, which you find as a stl file. To mount the circlip, screw out the conical rubber and slide the circlip onto the conical rubber thread.
mount the arduino to the T3PA pedals
Cut the circuit path like shown in one of the images. This will increase the readout rate from the loadcell from 10Hz to 80Hz
Connect the loadcell to the breadboard
Connect the breadboard vcc --> arduino vcc
Connect the breadboard gnd --> Arduino gnd
Connect the breadboard DAT:Option 1: If you have an Arduino (Pro) Micro, breadboard DAT --> Arduino 2Option 2: If you have an Arduino Due, breadboard DAT --> Arduino A7
Connect the breadboard CLK:Option 1: If you have an Arduino (Pro) Micro, breadboard DAT --> Arduino 3Option 2: If you have an Arduino Due, breadboard DAT --> Arduino A8
Open the attached arduino file
Install the HX711_ADC library link
and modfy it's "HX711_ADC.h", so that the value of "SAMPLES" is set to 4. This will decrease the low pass filter order and thus make it faster.
Connect the arduino via programming USB port
Flash the arduino with the attached file.Option 1: If you have an Arduino (Pro) Micro, please flash the file "brakeMod_Arduino_Pro_Micro_EEPROM.ino"Option 2: If you have an Arduino Due, please flash the file "brakeMod_Arduino_Due.ino"Option 3: If you have an Arduino Due with external EEPROM, please flash the file "brakeMod_Arduino_Due_EEPROM.ino"
Connect the arduino via native USB port
Loadcell calibrationOption 1: If you have an Arduino (Pro) Micro, open the Arduino IDE. Connect the Arduino to the PC. Open "Serial monitor" and type "calibrate", hit send. During the next 10 seconds hit the pedal mutliple times. The arduino will read the Loadcell and automatically adjust the Loadcell readings and map it correctly.Option 2: If you have an Arduino Due, during the first 10 seconds after you connect the Arduino to the PC, you need to press the brake hard and fully realese it multiple times. It will read the readout limits and use them for proper scaling the readout values. During the calibration time, you will see the internal Arduino LED blinking with 1Hz. After the calibration time, it will turn of the LED. This procedure needs to be repeated everytime you connect the arduino to the PC.
Install the Arduino joystick Librarylink
Open your racing simulation and adjust your controller settings the use the value from the arduino instead of the brake signal from the T3PA
Edit 08.10.2018:
Attached the "BrakerBumper1.stl" file, which you can use instead of the original rubber cone. It gives a much softer brake feel, similar to that in my private vehicle. Print with TPU with 4 perimeters, 15% infill, no top & bottom layer as seen in the images to achieve best possible braking feel.
Note:
I also attached files for a loadcell rubber contraption (holder + rubber). Tested the rubber printed it TPU, but it was not soft enough. In case somebody has softer filament, please tell me!