DIY FFB Steering wheel (MMosFFB ) (In Progress)

Hi, I am a new User. I have ı few questions. 1- I want a strong FFB .
Which engine should I use? 2- I cant found disc encoder in my location. Can ı use black rotary encoder and
how many ppr do i need . 3- I need wheel , pedals, shifter base layout. Thx for your help. My private email : enesbtfb@gmail.com

Hi everyone, so my DIY wheel is currently set-up with 2 RS775 motors connected in parallel to 2 BTS7960s connected in parallel too. I did this minimize the number of wires running from my motors to my control box and to ensure that they rotate identically. Would separating the motors and drivers (two sets of RS775 + BTS7960 connected to the STM32) instead of using them combined have any advantages?

I can't think of any obvious reason that it would or would not be recommended but consider the current source and sink ability of each.

i.e 2 Motors in Parallel is 1/2 the resistance, but you're doubling the current handling ability by 2 7960's in parallel too. However, by keeping them separate, it may 'load balance' better. It's hard to tell without testing directly but my guess is that the mechanical difference would be somewhat negligible.

However, if the motors are not perfectly matched (resistance etc), you may end up with one motor getting way more power than the other and more likely to melt rather than a true balance than you think you have. This may mean there is a reliability reason rather than a performance based reason to separate them.

If you want to try, leave the 7960 in parallel (inputs) but just change the outputs. There's no issue with them rotating identically as they don't really rotate (you're not matching speed/voltage), it's force applied which will still be cumulative from each motor.

I suggest using some sort of temp sensor to monitor each of the motors.

hello, if i use another motor rather then the denso one, do i need to make change in the firmware>?

What type of motor driver will you be using?
There is not much more to change in the fw except the PWM behavior, so probably no.

BTS7960 is the driver i intend to use. Can u tell me what is pwm behaviour? Im a beginner.

What microcontroller do you plan to use? If you are a beginner I would suggest EMC, it is quite easy to use. The STM or the Arduino that it uses is quite cheap too. The MMOS STM can be a bit pricey.

The PWM behaviour is how the microcontroller sends the force data over to the motor driver. It is different for different drivers. I think the BTS uses 3 signals; one PWM left, one PWM right and a "enable" signal. At least when you use the EMC.

I will use arduino leonardo

What firmware? EMC or Aiwave?

Im not sure yet. Cant understand whichi should i use. Can u help?

Like I said before, choose EMC. It is very easy to use and quite well documented. There are a few YouTube videos covering it. Search for Ebolz Magy

Thank you.

Which one is the best firmware? I may change my Setup according to that.

EMC

[QUOTE = "doddynco, post: 170342, membro: 26752"] Encontrei uma maneira de parar o atrito não preciso O : sorrir retorno da força melhorou maciçamente. Isso significa que a ponte H nunca aterrissa na configuração do loop de terra causada por ter R_EN e L_EN sempre em 5v.

O Mmos precisa ser definido como 'PWM & dir', 16,8khz. Coloque o pino 9 em L_EN e R_EN. Pino 11 a RPWM e pino 10 LPWM (dependendo da polaridade do seu motor, pode ser necessário inverter o pino 10/11)

Nesta configuração, 50% pwm = 0motor; Ainda não sei por que isso é verdade - mas é verdade, pelo menos para mim. A solução é definir o ganho mínimo de feedback da força do jogo em 50% - encontrarei um trabalho mais permanente em torno do uso de hardware, mas, por enquanto, funciona muito bem. Além do mínimo de FFB no jogo, use a configuração de ganho mínimo da configuração do mmos para o ajuste fino (cerca de 1% a 5% normalmente). Testado por mais de 40 minutos e o motor não estava mais quente do que na configuração antiga, pode até estar funcionando mais frio.

Como experimento, removi o capacitor pequeno de 300uf (fica no trilho de alimentação entre positivo e neutro) do IBT2 e funciona bem. No entanto, sinto um pouco mais de 'conversa' elétrica com os componentes - se esse é o termo certo . Enfim, acho que ele atua como um filtro para picos de tensão de frequência muito alta causados pela comutação PWM sob carga - tenho certeza de que o pequeno capacitor deve ser deixado no lugar.

O parágrafo a seguir ainda não foi testado, portanto, tente apenas se você conhece as implicações do que está fazendo - os capacitores são potencialmente muito perigosos:
Além do capacitor pequeno, acho que um capacitor grande de 2000uF + em paralelo ajudaria ainda mais a regular a tensão de alimentação. Espero que isso signifique que podemos girar a roda com ou contra o motor, e o trilho de alimentação mantém a tensão.

Por fim, para evitar o alto nível de força mínima do jogo, tentarei projetar um simples pós-processador pwm para fazer ...... <50% pwm = 0% pwm ....... 50% pwm = 50% pwm ........ 100% pwm = 100% pwm ....... para que não tenhamos nenhuma mudança desnecessária dos mosfets. Isso deve ajudar no resfriamento e em algumas outras pequenas coisas sem importância para os detalhes. [/ QUOTE]

Hi....

which pins on IBT_2 do you use?
I am currently using MMOS with STM32.
like this:
---------------
BTS | STM32
---------------
GND | GND
R_EN | 5V
L_EN | 5V
RPWM | PE9
LPWM | PE11

in MMOS

PWM Mode: PWM(H-Bridge)
PWM: 4.2khz
Encoder CPR: 8000 (my is 2000ppr)
Reverse Encoder: Unmarked
Use Encoder Index: Unmarked

Hello!
I looking for some motor to my ffb wheel.
https://www.robotshop.com/en/12v-dc-motor-251rpm-encoder.html (it's can too slow with this rpm? Can i use this encoder)

https://hobbyking.com/en_us/propdri...073&indexName=hbk_live_magento_en_us_products

Or which motors you prefer (i know my- and rs- ). I would use it with belt in ratio around 6-7Nm on wheel.
Thx for help

Hi @doddynco, first of all thank you for doing various tests and sharing them.
Soon I have to start the wiring of the stm32 + ibt2 too, would you advise me to connect as you say and put in MMos in PWM & dir mode and not use the H-bridge mode?
How did your final tests go after so long?

PS: I will use a 48v 1000w motor powered by 12v 100A

Thank you

Mmos needs to be set to 'PWM & dir', 16.8khz. Put pin 9 to L_EN and R_EN. Pin 11 to RPWM and pin 10 LPW. So it should look like this:

---------------
BTS | STM32
---------------
GND | GND
R_EN | PE9
L_EN | PE9
RPWM | PE11
LPWM | PE10
(depending on the polarity of your motor, you may need to reverse pin 10/11)
---------------
MMOS
---------------
PWM Mode: PWM & dir
PWM: 16.8khz
---------------
In game: Minimum ffb set to 50%

I definitely would recommend doing it this way providing the game you're using can do 50% minimum feedback. RF2 can do this and so can AC if you make a custom .csv(?) ffb curve.

I have some code which a friend wrote for me which should make the 50% minimum thing unecessary. It requires an UNO to post process the PWM signal. It's been a long time since I played with this but I intend to sell my converted MMOS twin motor T500 soon, and so I will have to finalise the project. I will be sure to post all of the wiring/instructions here (along with that code for the arduino) as it is a massive improvement over the original mmos wiring.

Thank you @doddynco, I wanted confirmation not to be wrong.
Unfortunately, I am unable to create a .csw file.
On other games how it works like Dirt rally, raceroom, Project CARS etc. etc.?

I look forward to the developments with Arduino

If I've remember this right, all you need to do for AC is add this into a txt file:


0:0
2:51
100:100

(You may need to invert these left to right - I can't remember which way round they're meant to be)

Then save and rename the txt file to myfile.lut.

Then edit and save the ff_post_process.ini as follows:

[HEADER]
VERSION=1
TYPE=LUT
ENABLED=1

[GAMMA]
VALUE=1

[LUT]
CURVE=myfile.lut




I don't know about the other games you mention, it really depends if they allow ffb minimum of 50%. (only 35% is really needed in-game as you can add in the first 15% in mmos.)