DIY FFB Steering wheel (MMosFFB ) (In Progress)

good effort ! - i use these for my motion sim motors and have a fan on them - they seem to work fine

my guess is the ffb wheel will deliver less heat - i like your adaptation of a PC cooling fan

I have got my DD FFB wheel working good if anyone is interested

project has been a success - thank you everyone for your help

you can see the build here -- https://www.xsimulator.net/community/threads/cousin-of-osw-open-sim-wheel.10915/

Dudes.

I have found there to be an issue when using certain encoders. Especially those cheaper ones from china.
These cheaper encoders have an output type called NPN. This is a type of transistor.

In short this will not simply plug and play and a modification must be made to the outputs of the encoder.
What is needed is called a pullup resistor. These are resistors in the range of 2k - 5k that are connected from A/B outputs to 5v.

These encoders that have a voltage range of 5v - 24v have an internal regulator which brings down the voltage to 5v and we will use this as the 5v source.

The connection of the pullup resistors are pictured: (the two blue ones with leads)


It is also advisable to use an external 12V source for these encoders as applying the 5v source from the MMos seems to be insufficient for the onboard regulator to work correctly.

you can also fit the pullup resistor on the input channel of your circuit board

Hi,
Does the OMRON E6B2-CWZ6C Rotary Encoder 2000P/R count as a cheap chinese encoder?
What is the advantage of soldering the resistors inside the encoder? If I don't want to risk opening the encoder case, does an external resistor between the input channel and the STM board have the same result?
I got it to work with the Leonardo, using 1k resistors, but no success with the STM32 board and MMOS.
I might be missing some detail. My search had no result so far.
I could use some help. Thanks in advance.

Yours is not a cheap encoder however it is an NPN output type. The only way I could get mine to work was by having a 12V input from a separate voltage supply and tied to 5v output of the onboard regulator as shown above. Opening the case is easy, just undo the screws and SLOWLY pull the case back. As you pull the case back feed a bit of cable back into the case so that you do not rip any wires on the inside.
Do this in a clean area so that you do not allow dust and debris to get on the encoder wheel.

I did some voltage measurements on the encoder outputs. Everything connected and the discovery board plugged in, the two encoder outputs had 5,3V when HIGH, 0,28mV when LOW. They changed accordingly between these values when rotated. Had the same results using 5V or 12V supply to encoder.
Does that mean the encoder is working as it should?

I also thought the problem might be on the software side, or I connected them to the wrong inputs. They are on PA0 and PA1 on the discovery board, as shown in some old drawing I downloaded with the MMOS instructions.

I finally got the encoder working with 1k pullup resistors. One thing is strange though. Is there any feedback in the MMOS software panel of the rotation? In the Game Controllers window I can see the axis moving, but in MMOS the Rotation Offset stays zero the whole time. Should that counter be active?

Hey, Alexy once you load the MMOs software to the Stm32f4 it shows up as a MMOs ForceFeedback device.
In this image, if DIY peddles were connected as in this image .. https://puu.sh/ysxDr.jpg using potentiometers
do you need any Code for them to work.Im new to this electronics stuff. Sitting in the back of the Brain [ oh its going to go bang or Smokes coming Next ]....lol.
Still, thats how we learn.

Thanks.

Hi, If you have downloaded all of the MMos zips then in there is a section that depicts connections for the pedals.
The specific zip file is labelled as "Anschluss" which has an image named "pedale". This image shows the connections for potentiometers for your pedals.

There is no code needed.

For your gears and other functions look at the picture labelled "Anschluss" and it shows connections for button 1 - 16. These are active low. So you connect these pins to ground to activate a button press.

Page 4 of this thread contains images for connections
https://www.xsimulator.net/community/threads/diy-ffb-steering-wheel-mmosffb-in-progress.7769/page-4

Hello!
What way i need to connect these wires?
Can someone help me pls?
here is the pistures of my arduino and the encorder.
P.S. Allsoo i have wires, switches for h shifter and 10k ohm encorders for gas, brake and cluth.

0v Gnd
Vdc 5v
A and B on pin0 and pin1
Z pin6

In the datasheet there are no internal pullup resistors, you need to use pullup resistors, but test before without.
See the image, got it from EbolzMagy youtube.

and from where 5V comes to resistors?

5v pinout arduino
See the previous image:
- 5v arduino connected to pullup resistors and VDC encoder (brown wire)
- GND connected to 0V (blue wire)

Ok
i did all that i wired it up but it doesn't show the wheel state all it shows is this...

what are your advanced settings ?

hello gentles,
I'm also working on building a Force Feedback Direct drive, but I'm trying a direct drive with a stepper motor, but with a low cost
So far the main thing to build a project like this is the driver for the stepper motor. I already found some drivers like the Argon driver with some auxiliary components which is able to control the stepper with the PWM sent by the DISCOVERY board (but the cost for this is way more then I want to spend, and close to commercial steering wheels).
Considering this cost, I started to think in a cheaper solution to the masses, but before executing this plan I would like a second opinion out it.

first two basic facts
1 - commercial steering wheels are based on torque control, so it can give a high torque for strong effects and lower torque for the weak ones.
2 - to control the torque of an electrical motor we need to control the current, in this case in the coils of the stepper motor.

Following this thinking, I made a lot of research and I found that the most of the "Chinese cheap drivers" have current control by chopping the current. The problem then was that the mode of we set this current control is mostly through switches, so we couldn't control it by Arduino(I choose Arduino because I couldn't find the code to modify the firmware of the discovery force feedback, just the .hex file to burn on it.)
Searching a bit more about chopper stepper drivers I found some circuits DIY based on the chip Toshiba tb6600, which can drive steppers using 10 to 42VDC up to 4.5A, and the mode of control of this circuit is via 10K pot, so the plan is to use one of this driver ( I found for 10 aud from China), and replace this pot by a X9C103 Digital potentiometer, so we can control it via Arduino

PS: As the intention is to build the steering wheel not the driver I'll jump this part and buy one of this,(if someone is interested just let me know that I can share the project of this driver and some more information that I found about Chinese drivers, because I am convicted that we can use this "mod" in any driver)



I will copy the main idea of another forum that uses an Arduino to convert the PWM coming from the DISCOVERY board into a percentage of effect intensity, to control torque( or percentage of Amps applied to the coils), controlling this way the torque.
The direction signal I will use to set direction and a constant speed, sending pulses to the driver ( I'm not sure about using a constant speed, but it looks like this is the way the commercial FFB wheels work, constant speed and variable torque depending on the effect)

if this plan works we can make a direct drive 13N.m for under 250 dollars.(this is cheaper then a logitec g29)
prices in aud
90 Keyway Dual Shaft Nema 34 Stepper Motor 13Nm
50 shipping for the motor
10 chinese driver
31 power supply 48v 5A
28 OMRON E6B2-CWZ6C Rotary Encoder 2000P/R New
25 discovery board
10 arduino
_________________
245 total

I would like to listen to a second opinion about this crazy plan before start buying stuff. Do you guys think this would work? any suggestion about the circuit or the mode of control?

Hi Henrique,

would like to see how you progress in your project. Maybe you get some inspiration from this thread https://www.xsimulator.net/community/threads/son-of-opensimwheel-an-experiment.7422/

Is this wiring correct? I tried so, but it didnt worked for me

You have advanced in your project, I am interested in doing a flyer, do you speak Spanish? could we talk from steam or email?