Finished 2DOF 12V DC wiper arduino playseat

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Finished 2DOF 12V DC wiper arduino playseat

Postby RacingMat » Fri 7. Jun 2013, 09:33

Thanks to Xsim software ;-) I have now the joy to drive my own dynamic 2DOF simulator !!
X-sim / Arduino / motomonster / 12V DC truck wiper motors

Years ago, it was really impossible to start such a project... without a software like Xsim !
But when I came back on the Internet in 2013 with this simulator project still in mind : I discovered Xsim and fully functional projets 8-)

So, I started a simulator and ... I finished it !!!

I'd like to share in return what I did, to help others as I've been helped by reading your posts

It's running in rFactor IA mode in order to show the maximum effects ! and prouve that wiper motors can be strong enough !
It can be smoother.



Among many designs, I finally choose to follow the building instructions of Lipide512, thanks to him for his great tutorial and his help !

The concept:
A dynamic simulator which integrates the driver, the seat, pedals and steering wheel (but not the screens !)
The two axes (2DOF: Two Degrees of Freedom) are : roll and pitch (roulis and tangage).


The principle is inspired by the commercial model from Frex
but with gearmotors (wiper motor + rod) replacing the electric linear actuators.

[*]This simulator uses the essential software Xsim to extract games telemetry data and send the data to the motors.

[*]Two computers :
Pc #1 (graphic card "7970 lightning", Windows 7) :

- The car games (Dirt3, rFactorLite and Richard Burns Rally)
- Xsim Sender

PC #2 (Recycling) connected via a crossover cable RJ45 to PC #1

- Xsim Profiler

[*]Electronic cards : Arduino + Motomonster

An Arduino card linked to computer #2 with a USB cable.
The Arduino controls the MotoMonster shield "motor driver board".

The power board Sparkfun "MotoMonster" drives the two motors (12V 47A = 575W) according to the instructions of the Arduino (5V 5mA = 25 mW).

For simplicity, the motor driver board is equivalent to 4 relays:

driving the right motor forward <-> this means mounting the right side,
driving the right motor in the other direction <-> this means lowering the right side,
driving the left motor forward <-> this means mounting the left side,
driving the left motor in the other direction <-> this means lowering the left side,

An arduino program (C language)

This program interprets the data sent by serial port xsim (instructions) and sends it to the motor control board.
It performs a feedback control by reading the values of the potentiometer coupled to the motors :
-> The actual position is compared to the setpoint, and this will create a new updated order sent to the MotoMonster card.

This feedback loop is performed every 80 ms.

A punchy 12V Power Supply Unit about 30A.

Electric Motors :

2 Truck Wiper Motors for actuating the movable platform, with their positioning potentiometer (for feedback).

Structure in rectangular steel tube:

- the frame
the frame rests on the ground and supports the movable platform via a motor drive shaft (U joint).

- the moving part: the "cockpit"

- A true racing bucket seat (tubular). The fiber seats are lighter but more expensive.
- A harness! important to feel the seat movements and for realism of immersion
- Force Feedback steering wheel and pedals

The dimensions
Here are the quotations to give you an idea :



The step-by-step pictures:


It was very convenient to have the bucket seat's mounting plate: I drilled the structure easily! (Uh, now it's for sale!)

Power Drill and a conical tool to adjust the hole to good diameter
Take care to ensure the shaft 's squareness : it has to be vertical !

Then I crossed the bars at 45 ° to triangulate my frame :

Here's the frame:

Look for a car or truck gimbal at scrap yard or
an ebay search "rear drive shaft" (don't buy a RC model shaft ;-)

The gimbal (U joint) is blocked in rotation along the yaw axis.


the gimbal assembly:

which gives this :-)
and this

Theignition key, of course = :))
a plate on the side of the wheel holder:
and here is a "starter / emergency stop" key §

The pedal support


the right bracket must be folded down!

folding legs with a hammer

The D5mm hole for a screw that will lock the support and prevent it from slipping

After welding, the result in perspective:

Dirlling of the pedals and support plate at the same time
Two-components glue bonding and 4 screws M5x16
take the opportunity to remove the unnecessary ballast which adds to the inertia of the system :)


after painting (and shorter legs):

and perspective view

The 4-point harness

In fact, it is a 6 points but it's too much ! and not comfortable : 4 is fine.

welding a small bolt

the clip can be mounted and removed

side view:


conclusion: the harness is great!

- For the look 8-)
- For immersion: it feels like being in a rally car!
- For sensations: I think we fight less against movements playseat, it is more inclusive

but it requires a keyboard support!

The bottom
To finish the structure, a wooden bottom on which I can put my electric stuff

Drilling diameter 4, threading M5 and screw

The rubber feet

Essential accessory: small rubber feet to absorb vibrations and provide stability on the ground.
Here are some hard plastic and adjustable feet

Width of the frame, I aimed a compact size to begin with
Edit: The first tests have shown that ... it was not wide enough!
then I added + 11 cm on each side (it must go through the door ^ -) for a total of 68 cm

The Center of Gravity cdg
I determined it with "precision" with an assistant:
on a tubular steel rod, roll frame until you find the balance
with the driver in it!
(the rod has to be perpendicular to the plateform !)

Mechanical part:

In Frex system, the seat is operated by electric actuators.
Xsim users recommand the use of SCN5 actuators. The Xsim application has a dedicated setting window.
But the cost was too expansive for me: € 320 each (the only retailer here (

So, the actuators are advantageously replaced by wiper motors and a system of rods (just 10 times less expensive).

Wiper motors

Edit : finally, this bracket is too short : I couldn't mount the 2 motors symmetrically .
If you can, make a DIY bracket with custom height.

-> And check that the rod can rotate 360 °.

Mounting with 3 screws M6 x 16 and washers

A steering rod (15 €):

A connecting rod:
- Center distance 65 mm (finally)
- 5 mm thick

With a file, try to file a 18° cone down : it has to go well on the motor shaft.
Tighten hard !


motors and rods final mounting
sanding the edges to remove the zinc coating of the bracket for a good welding

I checked the alignment of the motors with the platform (= I conterbalanced a small angular error during the welding of the platform)

Edit: the engine brackets are not stiff enough! they move under the constraints.
solution :

and I checked the rod could rotate freely at 360°
do not hesitate to do the same (one full turn may arrive more quickly than you think :-)

here the assembly of the connecting rod with the movable platform :

Fixing rods on the platform:

we notice the hexagonal hollow: handy to tighten nylstop nut for example :-)
it works well for top seat side.

On the other end, I shortened the length of the threaded rod so that it can rotate 360 ° without stumbling. There is a problem : the spindle mounted on ball, turns on itself when i tighten the nylstop nut : '(
So I made a hacksaw deep enough to insert a screwdriver while I clamped the nut.


Mounting potentiometers
wiper motor's preparation = fixing the pot at the back of the engine

1 / tapping of the smooth hole of the engine
2 / a M4 threaded rod
3/ a 6mm diameter (like pot) spacer and M4 tapped


assembled with loctite:

then the parts for making a rotational connection adjustable to adjust the potentiometer
(The brass piece is ... a 380V connecting block course!)

This solution is rather excellent!
it is tight enough to but if it goes too far: the pot is not damaged, it slips.

Making a light and flexible bracket for the pot: it should mainly prevent its rotation and absorb a bit of eccentricity.

thickness: 0.8 mm for soft and flexible
Overall un-folded dimensions: 50mm x 129 mm

the first bracket and the second waiting!

overview !

Engine and rods mounting :

- Make sure the platform is horizontal (spirit level)
- the 2 rods has to be perpendicular (red square on picture)

For the electronic part:
The 12V power supply 47A
eBay, the DPS-600bp model ( ... pb&_sop=15) is 30 € with shipping: 575W
The mod is very light! ad here
There is not need to open the block and therefore no risk of electric shock.

Cards: Arduino and MotoMonster:

here is the wiring diagram I followed from Lipide512


I chose not to stack the two cards although it is expected to:
- I wanted to keep me a chance to reallocate the outputs of the Arduino
- I wanted better cooling system (so I raised the motomonster)

If you bought the Motomonster board, the simpliest is to stack it onto Arduino !

If you don't, you have to follow the following pinout :
Arduino and Motomonster have same pin's number !
connect together

Arduino .../...Motomonster
......GND <-> GND pin
........5V <-> 5V 4 <-> pin 4 5 <-> pin 5 6 <-> pin 6 7 <-> pin 7 8 <-> pin 8 9 <-> pin 9

pin 13 is not needed
on the pictures, I've soldered more wires (but they are unused wire...).

Alternative: the olimex VNH3SP30 works like Motomonster VNH2SP30: 1 pin for PWM speed, 2 pins needed for direction
and can handle 24V
and so the code is compatible!

specs ... h3sp30.pdf

The Olimex board (integrating VNH chip) pinout is:
Olimex pin 5 = inA motor1
Olimex pin 4 = inB motor1
Olimex pin 6 = pwm1

Arduino /.. VNH3SP30 motor1
Ard GND <-> Olimex GND pin
Ard 5V <-> Olimex 5V
Ard pin 4 <-> Olimex pin 5 inA motor1
Ard pin 9 <-> Olimex pin 4 inB motor1
Ard pin 6 <-> Olimex pin 6 pwm1

Arduino /.. VNH3SP30 motor2
Ard GND <-> Olimex GND pin
Ard 5V <-> Olimex 5V
Ard pin 7 <-> Olimex pin 5 inA motor2
Ard pin 8 <-> Olimex pin 4 inB motor2
Ard pin 5 <-> Olimex pin 6 pwm2

Arduino / Potentiometers
Ard pinA4 <-> center pin of pot 1
Ard pinA5 <-> center pin of pot 2
Ard pinGND <-> 0 ohm's pin potentiometer 1 & 2
Ard pin 5V <-> 10k ohm's pin potentiometer 1 & 2

First movement tests
a video to show the amplitudes of movement of the cockpit and the moving speed.
The position commands are typed by hand in the arduino serial monitor (RF7LF7 then RAELFF etc ...)

Heat sinker had to be cut in half in order to have a good contact with the 2 chips (uneven)

go for the thermal paste

spreading the paste:


Protection for cables :
-> electrical conduit
-> A notch

-> And insert in the hole!

the cover of the electronic cards with his fan

+ a grid that prevents the wires to be worn against the fan's blades.


a glogal overview of the electrical stuff:

For your information, here the wiring for 2 motomonsters and 1 arduino if you intend to build a 3DOF or 4DOF

If you're using more powerfull motors, you can use one Motomonster per motor. Follow the specification of VNH

Arduino configuration :
PC1 : Games & Sender
windows seven
IP fixe : (TCP/IP v4 protocol)
this PC runs the games
and Xsim Sender

PC2 : Profiler
windows seven
IP fixe : (TCP/IP v4 protocol)
this PC runs Xsim Profiler
and communicates with Arduino via USB serial cable.

*/ Arduino : install manually the drivers (see the Arduino's documentation for Windows Seven installation).
After complete installation, find in the Windows system on which COM Port it has been installed : you will need to put this information in Xsim Profiler.


Double clic on Arduino's line and adjust the default speed :

In the Arduino plateform, put the right COM Port : if not, you won't be able to upload your program into the Arduino...

If you need to lead some communication tests, use the Serial Monitor ("magnifying lens" on top right ).

Adjust here as well the same default speed :
and you will have to copy this very same information in Xsim Profiler !

Arduino's code

see finished project topic here viewtopic.php?f=36&t=1617

copy/paste the code in a "sketch" (.ino file) and upload it into the Arduino

first hardware tests and trials

First : your pot are not mounted onto the motor
you can see the expected behaviour in this video
and please find the explanation of the code here :

The code is written to put the simulator on middle position at start :
/* init position value*/
int DataValueL=512; //middle position

- if your pot is fully turned to max, as Arduino "reads" potentiometer value as motor position, Arduino believes that motor is in max position.
- but the order is to be in middle position
- so the Arduino will ask the motor to go reverse in order to go to middle position
- your motor is turning
- but while your pot keeps still, the motor will turn non stop !

- when you manually turn the pot backward to min, Arduino reads that motor is in min position
- but the order is still middle position, so Arduino will tell the motor to go forward
- motor runs non stop until the pot is in middle position

In the code, you have a "tolerance" parameter : when the pot is around middle position (<middle+tolerance and >middle-tolerance), the motor stops.
You can broader Tolerance value to stop your motor more easily manually.

Second : now checked the wiring
Once you have played in this manner, now checked the wiring
simulate the pot mounted onto the motor (back to back or alongside with gears...)
reduce the speed (pwmMax) to see the direction of motor rotation
and check if Arduino will behave as expected when you turn the pot

if your pot is mounted this way :

when you turn in a direction, motor has to go the opposite way.
If not, invert motor wiring or pot wiring.

Warning ! if you have gears between pot and motor, you'll have to twist your mind :eek: to check the correct behaviour.

Third : mount the pot onto the motor, the behaviour will be the following :
- motor goes to middle position and stop
- if you send order to Arduino via Serial Monitor (say R7FLAE) the left motor will move and stop at his new position ! right motor didn't move.
- etc...

First serial tests: without Xsim
For beginning, start by sending yourself instructions to the Arduino and to your motors...
No need at this stage to use Xsim and Game's data !

L for Left
R for Right

8 bits resolution and hexadecimal output
-> value in hex varies from 01 to FF
01 full speed reverse
7F stop
FF full speed forward

-> value in decimal (more explanatory) varies between 0 to 255
0 full speed reverse
64 mid speed reverse
128 stop
192 mid speed forward
255 full speed forward

In the "Serial Monitor" send the following strings in Hexa and Enter:
-> it should move the playseat in horizontal position

R01L01 (max !!)
-> it should tilt the playseat backward and a bit further

RFFLFF (Max !!)
-> it should tilt the playseat forward and a bit further

You can mix for rolling movment :
R01LFF (Max !!)
-> roll left

RFFL01 (Max !!)
-> roll right

Xsim setup
you can upload the file (rename it to .rn2) from Kalarius ;) here

Then in Xsim Profiler / Output / port com

serial Port configuration :
select the right arduino's COM Port

if you don't find it in the drop box, write it directly (as explained below the drop box on the screen) like this \\.\com4

For rFactor game (and many other games) :
- find its plugin (if it exists or a compatible one) in the Xsim's plugin's directory : copy it
- paste it in the plugin's directory of the game

Xsim sender (running on the Game PC#1) defines the following parameters :

IP address of the 2nd PC
the path of the game executable file
the plug in being used
informations for the joystick ...

Easy !
These parameters are saved in a text file with .fsd extension (XSim 2)

Xsim profiler (pc #2) transforms and combines the telemetry data in order to get an order for each motors.
Muy difficil !!!

- serial link choice (for me and my Arduino, its USO not synaptrix)
- Axe 0 : combination of (lateral, longitudinal, pitch ...) game telemetry effects to calculate the right motor's position
- Axe 1 : combination of (lateral, longitudinal, pitch ...) game telemetry effects to calculate the left motor's position
- some general parameters of the software
- serial link's configuration : port number, data's format (for me, its R~a02~L~a01~)

These parameters are saved in a text file with rn2 extension (XSim 2)

select your "Right DOF" and type the format awaited by arduino "~a0~"
8 bits resolution and hexadecimal output
watch out, the ~ characters are mandatory !

the same with "Left DOF"

"Output Protocol Parser" (the values that will be sent every cycle) :

packet send on start : R7FL7F
this is a middle position (ie the simulator is parallel to the ground) (7F = 127 : mi-course de l'amplitude des potards = niveau 0)

data's format :
it means that the values of a0 are sent to the "Right motor/DOF" and the same for a1 and Left Motor

packet send on simstop : R7FL7F
when Xsim stops sending game telemetry's data, it puts the simulator back to the midlle position


On the next picture, I show the different ranges and conversions through all the stages from the game / Sxim / Arduino / pot / motor
it useful if you need to understand the code ;-)


Items to buy
- motors 12N.m 24V : 2x35€ + 16€ shipping
SWF VALEO NIDEC ITT 404.458 motoréducteur 24V DC

- Arduino board : 25€ + shipping

- MotoMonster board (16V max) :
70€ @ Sparkfun
27$ @ DX

- you can use 2.5mm² wires or bigger
@ 20A continuous
and 30 cm length between driver and motor
-> the wire will heat 37°, which is below the 60° max heat. ... article=88

Have shortest possible wires between driver and motors!

RacingMat wrote:You can find some Motomonster on Aliexpress @ 14$ :)

or you can use OLIMEX with 24V
9$ per motor ... -VNH3SP30/

- server PSU 12V 47A (575W) DSP600 : 35€ on eBay

- 2x potentiometers : 2x7€ + shipping
you can buy any cermet potentiometer : "cermet" means Ceramic Metal.
It guarantees you that it's the strongest design compared to plastic-carbon low cost pot.

- cermet
- linear (not logarithmic)
- 10 kOhm

I bought mine at ... -11293.htm
you can find here many other electronic distributors :

+ my plateform structure weight 8,6 kg
tube 30x20x1,5 (1,1 kg/m) 5,4m : 5,9 kg
tube 16x16x1,5 (0,7 kg/m) 4,1m : 2,7 kg
+ rally tube seat : 9 kg
+ rally harness : 1 kg
+ logitech MOMO wheel and pedals : 4,5 kg
+ buttkicker 1 kg
subtotal : 25 kg

+ driver !
grand total : 100 kg which is heavy and has great inertia in mouvements !
-> so keep in mind to build light

Electrical power consumption

I measured the power with this wattmeter : 1961

PC#1 Games : 80 to 100W
PC#2 notebook : 30 to 45W
Dolby 5.1 : 15W
Power supply PSU : in IA mode rfactor which sakes a lot ! between 170W and 220W (depending on the parameters in Arduino code : max speed and amplitude)
the PSU efficientcy is 81%, hence it gives 180W to the motors.

-> 90W per motor -> 7,5 A in 12V DC
Last edited by RacingMat on Wed 3. Feb 2016, 12:27, edited 32 times in total.
2 DOF playseat : arduino, motomonster, 12V truck wiper motors
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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby Racerr87 » Fri 7. Jun 2013, 18:36

Very nice!
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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby prodigy » Fri 7. Jun 2013, 22:45

Very good and detailed project, maybe just add some X-Sim setup screens too and it will be complete.
It's nice to see Arduinos in action.
And looks like those rubber feet absorbed vibrations pretty good, it looks much better than without them like in your second video.
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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby RacingMat » Sat 8. Jun 2013, 15:55

@ Racerr87 : thanks ! it represents one month of intensive reading and 2 months of work

@ Prodigy : thank for your opinion !! In reply to your message, I've uploaded images on Arduino's and Xsim's configuration
and wrote some instructions in the first post.

Between the 2 videos, there is a difference : I enlarge the base as it was too instable (and the soft rubber feet amplified a lot the problem...)
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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby vicpopo » Sat 8. Jun 2013, 19:23


Super boulot , super bien détaillé pour aider ceux qui sont tentés par l'aventure.J'ai lu sur le forum gameover le super 2dof de lipid512 , super boulot aussi.Pour le problème de chauffe pas grand chose à faire ou changer pour des moteurs plus puissants.

Very nice job .Nice to see the french guys here on the xsim forum for sharing them job.

Good thread with many details from the building. ;)
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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby RacingMat » Sun 9. Jun 2013, 10:10

Thanks !

I've added some explanations in the first post for configuring Xsim for my 2DOF.

For the temperature, my motors are just fine, not hot (even after an hour !!)
(it's written somewhere in the Lipide512 post ?)
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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby sirnoname » Sun 9. Jun 2013, 12:53

Hi Mat,

great docu.
Some question: Is this firmware written by yourself?
Do not see a dl :(

If a answer is correct or did help you for a solution, please use the solve button.
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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby RacingMat » Sun 9. Jun 2013, 18:24

@ SirNoName : thanks for your positive opinion !
This gives me the opportunity to tell you that I'm grateful for your Xsim programming ;)

The Arduino's program has been written by a french guy (mentioned at the top of the code).
It is based on the example given by Sparkfun who sells the motor driver card "MotoMonster".
So I've mainly re-read it, streamlined few things and added comments (in english) for a better understanding.

I've inserted the code at the end of the first post.

Next steps, I'd like to give a try to improve the speed of execution (Analog to Digital Conversion's overclocking for example).

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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby futuresims » Wed 12. Jun 2013, 01:47


I give you 5 stars out of 5 stars.

You did a really fine job of documenting your work.

You are a very inspirational person!

This is what X-Sim is all about.

X-Sim is about inspiring other people to build their own motion simulator.

When people document their work with complete measurements, pictures, videos, and wiring diagrams, it helps to inspire others who follow you.

When others see your work and work well documented like you have done, others will see that they too can do this.

Thank you very much for your Great work.
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Re: Finished 2DOF 12V DC wiper arduino playseat

Postby RacingMat » Thu 13. Jun 2013, 22:02

Thanks Futuresims ! I appreciate that even more because you're posting some very detailed and interesting posts !
(so you know well how often it requires to disassemble everything only for taking a good picture to share...)

I wish you to succeed in your playseat construction project ! Driving it, is such a reward and such a pleasure !!
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