Has Anyone Ever Had This Problem With Their Pedals?

[GeekyDeaks]

I noticed that the new set, like my current Thrustmaster T-LCM, reports from 0 to 65,535. My old set also did 65,535 total but reported from -32,767 to 32,767. I know it's the same thing but is that a sign something was updated, or can that easily be changed in the underlying calibration program (eg. FreeJoy) with just some clicks/keystrokes?

In the USB HID spec (section 5.8) it states:

If Logical Minimum and Logical Maximum are both positive values then a sign bit is unnecessary in the report field and the contents of a field can be assumed to be an unsigned value. Otherwise, all integer values are signed values represented in 2’s complement format.

What this means is that they are not just the same values displayed differently and would suggest that both the HID Report Descriptor and Encoding of the values are different between the two. It seems odd for something like a clutch, brake or throttle to have a negative value as it's not clear what it would represent when it is negative, and you are at the mercy of the software using the values to 'do the right thing' so the updated range looks more sensible to me.

 

[Spinelli]

In the USB HID spec (section 5.8) it states:

What this means is that they are not just the same values reported differently and would suggest that both the HID Report Descriptor and Encoding of the values are different between the two. It seems odd for something like a clutch, brake or throttle to have a negative value as it's not clear what it would represent when it is negative, and you are at the mercy of the software using the values to 'do the right thing' so the updated range looks more sensible to me.

Good to know. Thanks.

Is that a potential sign of hardware differences between the 2 or is that just software/firmware setup stuff?

 

[GeekyDeaks]

Good to know. Thanks.

Is that a potential sign of hardware differences between the 2 or is that just software/firmware setup stuff?

My guess would be the range change is just a firmware difference. It doesn't rule out a hardware change to address the issue you have experienced though. Did the seller give any insight to possible changes?

 

[Spinelli]

My guess would be the range change is just a firmware difference. It doesn't rule out a hardware change to address the issue you have experienced though. Did the seller give any insight to possible changes?

I asked if any upgrades/changes happened in the past year or so (I purchased the first set in Feb or March 2022). He said no changes. I guess I just got unlucky with a defective set.

 

[Spinelli]

I received the pedals 2 days ago (arrived in 6 days, unexpectedly fast).

To my great frustration, the issue with the throttle and clutch still exist. It's much more difficult to tell if the brake has the issue but the throttle and clutch have it 100%.

- 1st part, throttle & clutch out of game
- 2nd part, throttle & clutch in ACC w/ PC load light = preset @ Low, framerate limiter @ 30, resolution scale @ 50%
- 3rd part, throttle & clutch in ACC w/ PC load heavy = preset @ Epic, framerate limiter @ unlimited, resolution scale @ 200%

I wonder if other people with the same or fairly similar pedals (eg. SimJack, Simsonn, Rui To, SimX, SimForge, etc.) just never noticed the issue or if they genuinely don't have the issue. Or if they just ignore it and don't mention it in posts / reviews / videos. Or what.

I'm assuming electrical parts like ADCs (analog-to-digital converters), amplifiers, controller boards, etc. aren't identical between the different "brands". If that's the case, then it's entirely possible that the other "brands" don't have the issue.

 

[Deleted member 197115]

HE Pro I had didn't have that issue, neither Simtrecs. May be going with mainstream reputable brand is not such a bad idea after all.

 

[mteam]

Maybe @Jeremy Ford could test the sim jacks for this issue. I always find his reviews great

 

[GeekyDeaks]

This might not be relevant, but you said earlier that the new set was reporting only positive values, however the vid is showing negative ones.... is it definitely the same board?

 

[Spinelli]

I might keep them and just calibrate the throttle and clutch for the worst case scenario. If I calibrate for a worst case scenario, it means when in a lighter scenario (say playing RF1), my pedal will reach 100% throttle when I'm "only" pressing the throttle and clutch like 99% or 98%. It's just a tiny bit of movement before the throttle physically stops. It doesn't seem to interfere with my driving because when I lift the throttle slightly from full-throttle, or if I want to press the throttle almost fully but not quite (say 95-ish percent), I'm still not at the physical zone where the pedal is reading 100%. I made that sound confusing, lol.

Basically, sometimes the brake inputting 100% throttle a tiny bit before it physically hits the stops is not causing any problems - not with throttle application, fine throttle lifts/modulation away from full throttle, etc. - because the point this can happen is just too close to the physical stop, at least in quick testing.

Maybe @Jeremy Ford could test the sim jacks for this issue. I always find his reviews great

I asked SimRacing604 if he could do it with his SimJacks and SimForge. He said he hasn't checked but that it would be an interesting experiment. Hopefully he checks.

 

[stigs2cousin]

It´s always a good idea to have small deadzones in you throttle.
I once found out that I had phases where I thought I was WOT but wasn`t.
The throttle was calibrated too "tightly", as soon as the foot relaxed a little from pressing into the endstop the graph fell.
Calibrate a 3% deadzone, problem solved.

And , scnr, I have to double down on on the "buy once, cry once" philosophy.
How many month of trouble free racing would you have had if you´d bought "the real thing" from the beginning?
And I have learned the hard way, same as you

 

[Neilski]

To my great frustration, the issue with the throttle and clutch still exist.

Are you gonna break out a multimeter and check if the voltage arriving at the pedals is drooping? (Or even HWinfo64.)
I (mis?)understood that the reason you didn't already do that is because you had returned the pedals before creating this thread.

 

[Spinelli]

Are you gonna break out a multimeter and check if the voltage arriving at the pedals is drooping? (Or even HWinfo64.)
I (mis?)understood that the reason you didn't already do that is because you had returned the pedals before creating this thread.

You didn't misunderstand This is the re-purchased set. When these recent exact models dropped from the usual $450-$550 USD to around $335 (prices include shipping / free shipping), I had to give them another shot. Plus, the seller I got them from this time is the actual maker (SimDT AKA DT Sim Racing) so I can talk to him even about things like bearings, rods, etc. Most others sellers are clueless.

I haven't checked my USB. I don't have a multimeter, however, I unplugged all other USB devices (except mouse and keyboard) - no difference. I also tried different USB ports - no difference.

I have a powered USB hub coming tomorrow to test...Assuming it is a motherboard-USB port power issue, should a powered USB hub solve it?

Assuming the pedals still show the same problem with the powered USB hub, does that rule out motherboard USB port power issues or should I still get a multimeter?

 

[Neilski]

I have a powered USB hub coming tomorrow to test...Assuming it is a motherboard-USB port power issue, should a powered USB hub solve it?

Ummm, probably/maybe?
It's such a weird fault I have no confidence what the cause could be, but strictly I should say yes - that if it's down to the mobo USB power delivery then a powered USB hub should sidestep that entirely...

Assuming the pedals still show the same problem with the powered USB hub, does that rule out motherboard USB port power issues or should I still get a multimeter?

Well if the powered hub doesn't help, we're into some weird parallel universe I guess
A multimeter would maybe help explain it, but I guess that's a bridge to cross if the hub doesn't help.

Can't recall if you ever stated whether HWinfo64 was reporting any variations (you can watch min/max) on the 5 volt lines under load?

 

[Spinelli]

Ummm, probably/maybe?
It's such a weird fault I have no confidence what the cause could be, but strictly I should say yes - that if it's down to the mobo USB power delivery then a powered USB hub should sidestep that entirely...

Well if the powered hub doesn't help, we're into some weird parallel universe I guess
A multimeter would maybe help explain it, but I guess that's a bridge to cross if the hub doesn't help.

Can't recall if you ever stated whether HWinfo64 was reporting any variations (you can watch min/max) on the 5 volt lines under load?

Haha. OK, sounds good. I'll check HWInfo.

Maybe @Jeremy Ford could test the sim jacks for this issue. I always find his reviews great

Is that Sim Racing Corner? If so, he responded quickly and we spoke back and forth. He said his tests don't show the issue. Seems like a good guy.

If the issue is my PC, I'm going to owe these pedal guys a huge apology especially considering it'll mean this thread is giving them false & negative coverage...but let's see first.

 

[Spinelli]

Just tested with HWInfo on Win desktop and then in ACC with the following settings: epic preset, res scale: 200%, fps limit (in-game & gfx driver): disabled, VSync (in-game & gfx driver): disabled, time: 12:00 AM, weather: storm, opponents: 29, track: Monza, starting position: last, start of race (as cars start moving to begin the formation lap)

HWInfo +5V
Desktop: 5.010 V - 5.020 V
Game: 4.880 V - 4.910 V

Don't let the negative numbers below confuse you. The closer to 0, the more throttle is being given.

Pedal, 0 physical travel (firmware raw value, only visible in Freejoy)
Desktop: -21,200
Game: -21,600

Pedal, 100% physical travel
Firmware raw value (approx), only visible in Freejoy:
Desktop: -9000
Game: -9700 to -9600

DiView / DXTweak2 raw value:
Desktop: 32,767 (100%)
Game: 29,191 (94.54%) to 30,034 (95.83%)

DiView / DXTweak2 value:
Desktop: 65,535 (100%)
Game: 61,959 (94.54%) to 62,802 (95.83%)

So, when applying 100% physical throttle during heavy graphics load, there's about a 4-5.5 % drop in the final brake input signal.


P.S. This is with calibrating the pedals so 100% input is when I give it 100% throttle (-9000) at the desktop. I did not give it extra calibration to make up for the heavy PC load issue. I did this to make the issue more visible for the sake of testing.

 

[Deleted member 197115]

HWInfo +5V
Desktop: 5.010 V - 5.020 V
Game: 4.880 V - 4.910 V

That could be your answer, you are not getting 5V under load. Hopefully powered USB hub will sort this out.

 

[Spinelli]

That could be your answer, you are not getting 5V under load. Hopefully powered USB hub will sort this out.

Every where I checked says getting 4.9 even 4.85 while on very heavy load is fine and common.

Also, this doesn't happen with any other pedals, then again the T-LCM throttle and clutch are not loadcell. Iit is a PC problem, is possible it can only affect loadcell but not hall-effect pedals?

Official ATX specs say 4.75 V - 5.25 V is the acceptable range.

Do you think it's maybe simply the GPU / PC system causing tons of noise throughout the "electricals" and therefore the electronics on the pedals and/or controller board can't handle it?

 

[Deleted member 197115]

EMI is a known thing that affects load cell amps. Usually if you ground the amp it shouldn't be an issue. Does set come with grounding wire, did you install it per instruction.

 

[Neilski]

HWInfo +5V
Desktop: 5.010 V - 5.020 V
Game: 4.880 V - 4.910 V

Yay, we finally have a (probable) smoking gun.
Kinda weird though, because on my PC, when I stress it, only the +12V line droops; the +5V is rock solid. This makes sense to me because all of the load is on the 12 V rails.
Is your power supply flaky, or being run near its limits? Replacing it may be worth considering...

Every where I checked says getting 4.9 even 4.85 while on very heavy load is fine and common.

Yes, almost all USB devices will work with a lower voltage, but...

My first guess (caveat: written in haste, may be nonsense! ) would be that the pedals are using the raw USB voltage straight to the pots (are your pedals using pots? I can't remember, but it doesn't necessarily affect my argument here) but are using a voltage reference from something stable (Zener diode?) for the ADC. This means that the ADC is comparing something variable with something fixed and your digitised pedal position becomes a function of the actual pedal position AND the USB voltage.
If they instead used the USB voltage as the reference for the ADC, the digitised value would be independent of fluctuations in the USB voltage...
(Does that make sense?)

 

[Spinelli]

Yay, we finally have a (probable) smoking gun.
Kinda weird though, because on my PC, when I stress it, only the +12V line droops; the +5V is rock solid. This makes sense to me because all of the load is on the 12 V rails.
Is your power supply flaky, or being run near its limits? Replacing it may be worth considering...

Yes, almost all USB devices will work with a lower voltage, but...

My first guess (caveat: written in haste, may be nonsense! ) would be that the pedals are using the raw USB voltage straight to the pots (are your pedals using pots? I can't remember, but it doesn't necessarily affect my argument here) but are using a voltage reference from something stable (Zener diode?) for the ADC. This means that the ADC is comparing something variable with something fixed and your digitised pedal position becomes a function of the actual pedal position AND the USB voltage.
If they instead used the USB voltage as the reference for the ADC, the digitised value would be independent of fluctuations in the USB voltage...
(Does that make sense?)

All 3 pedals use loadcells.

PSU is an Antec HCP-1200. HCP-1200 is very high-end with OEM Delta parts inside. It's comparable to PSU series like Corsair's top-of-the-line AX and EVGA's G2/P2/T2.

How much GPU power was used with your stress test?

Multimeter and powered USB hub arrived. Will test in the next hr or so.

If any drop or rise in 5v rail results in different pedal readings, would you say that's a pedal design flaw (or at least design oversight)? Even of the 5v rail doesn't drop to 4.9-ish V, it'll still drop nonetheless with any PSU (eg. 5.13 V to 5.05 V).