G25/G27 pedals to USB - How to?

[Leon Charmant]

I'd like to use my G27 pedals as a standalone device (since I don't have a G27 wheel), so therefore I'll need to connect it to my PC directly via USB.

I know of the Bodnar cable, which does exactly that, but I'd like to try something else first. And, my question to you is...: will this also work?

1. I'd connect my pedals to a female-to-female D-SUB 9 piece, as shown below.
   
   
   
   
2. I'd connct this USB to D-SUB 9 adapter converter to the above piece, and then plug it directly into my PC with the USB end (a driver for this adapter is included).
   
   

I don't know anything about hardware, so therefore I'd like to know if this would work exactly like the Bodnar cable would. In my mind it should, since I've essentially "converted" the pedals to USB via this 'chain', but I might as well be sure...

Thanks!

 

[RaceWasGood]

Can't answer your question, but if you end up taking the Bodnar cable route i have a cable/adapter for both the pedals and the wheel, that i'm willing to let go in exchange for a small donation. Cheers and good luck with your project!

EDIT: The other adapter is for the shifter of course and not the wheel...

 

[PicoBp]

It won't work. The Bodnar cable also has some built-in electronics that translate the pedal signals to USB inputs, and comes with its own driver as well.

 

[Leon Charmant]

It won't work. The Bodnar cable also has some built-in electronics that translate the pedal signals to USB inputs, and comes with its own driver as well.

Thanks for your reply! That was exactly the information I needed

I sent RaceWasGood a PM.

 

[Neys]

Old topic I know - I thought I'd let you know about a cheaper alternative here if you know how to handle a solder iron - I'm obviously affiliated with this project...

GitHub - n-e-y-s/G27_Pedals_and_Shifter: Arduino USB interface for Logitech G27 Pedals and Shifter

Arduino USB interface for Logitech G27 Pedals and Shifter - n-e-y-s/G27_Pedals_and_Shifter

github.com

Nice things about it: only one adapter for shifter and pedals, filtering possibilities for efficiently reducing spiking with worn pots, ability to mod the code on the Arduino to fit your needs. I really like this solution

 

[GeekyDeaks]

Nice! I have been considering using one of my spare arduinos for something like this so I could remove the slight mapping the wheel applies to the brake pedal input on the G29 (to offset the rubber block) and maybe also look at building a shifter.

I'll probably have a proper play in a few weeks, but I was wondering if you calculated the input lag when using the filter at various sizes? I haven't used the ADC feature in mine seriously yet, so I'm not sure of the sample rate and I was kinda curious why you settled on `#define MAX_FILTER_SIZE 49`

EDIT: ignore me! I just re-read the filter and realised I misunderstood what you were doing with the arrays. I thought you were buffering the values but I can see you are ordering them to determine the median. I had expected to see a low pass filter with a simple mean calc on a ring buffer, but I was wondering why you decided on a more complex process to use the median instead?

 

[Tronicgr_6DOF]

Maybe use stm32f4 MMOS that can read the G27 pedals and G27 shifter, and as bonus perhaps add a DD with cheap servo on it

Thanks
Thanos

 

[GeekyDeaks]

I have some spare arduinos floating around, which is why I was considering that approach for prototyping. Normally I'd build a bespoke circuit around a PIC, but the stm32f4 has a crazy spec for the price, so I might take a closer look. Ta!

 

[GeekyDeaks]

Ah! @Tronicgr_6DOF, I have just seen your TDD updates on youtube and realise what the board above is for now! Nice work

 

[Neys]

I'll probably have a proper play in a few weeks, but I was wondering if you calculated the input lag when using the filter at various sizes? I haven't used the ADC feature in mine seriously yet, so I'm not sure of the sample rate and I was kinda curious why you settled on `#define MAX_FILTER_SIZE 49`

EDIT: ignore me! I just re-read the filter and realised I misunderstood what you were doing with the arrays. I thought you were buffering the values but I can see you are ordering them to determine the median. I had expected to see a low pass filter with a simple mean calc on a ring buffer, but I was wondering why you decided on a more complex process to use the median instead?

The frame rate is about 500 FPS / 2ms in the arduino, so the lag introduced by the filter is approximately filtersize/2 * 2ms; For the maximum size of 49 this would be appr. 50ms. Median has the advantage over a simple mean or other linear filter to be robust against outliers. When the pots are worn (like mine) the pedals tend to spike and a median filter of suitable size is able to completely filter out the spikes. A low pass filter on the other hand will integrate all the data and so spikes will always have an effect unless the filter is much larger than the corresponding median filter.
The implementation is quite efficient even on the tiny arduino.

 

[Chris Canfield]

hello. I'm trying to figure out how I can convert a Logitech G29 pedal potentiometer to a direct USB cable.

My USB type a internal cable wiring is like shown in image below.

My USB type A plug looks like image: "a)".

My pedal potentiometer looks like the image shown below.

What & which wires on my USB-A cable that I connect to the potentiometer termanels SHOWN ABOVE, ?

Any advice on this issue would be great, & thanks !

Chris Canfield.

 

[Tronicgr_6DOF]

hello. I'm trying to figure out how I can convert a Logitech G29 pedal potentiometer to a direct USB cable.

My USB type a internal cable wiring is like shown in image below.
View attachment 446914

My USB type A plug looks like image: "a)".
View attachment 446915
My pedal potentiometer looks like the image shown below.
View attachment 446916
What & which wires on my USB-A cable that I connect to the potentiometer termanels SHOWN ABOVE, ?

Any advice on this issue would be great, & thanks !

Chris Canfield.

Sorry to break it to you, the potentiometer itself will not enumerate as USB device, especially not as joystick

You need to place in the middle a microcontroller that has USB stack, haptic device descriptor stack (joystick in plain language) and ability to read ADC input to measure the potentiometer voltage...

Just saying

 

[AmazingReflex]

Look at this for example. I haven't done this myself but I have managed to get an Arduino Pro Micro set up as a button box device to my PC.

Thrustmaster T3PA DIY USB Adapter - YouTube