tloimu

Quick update. Got Constant, Sine and Square effects implemented and working in both x-y-axis with proper directions on my modded MSSW FFP. It has L298N H-bridge (with 12V wall wart) connected to Teensy 2.0 running the adapt-ffb-joy's direct-drive code branch. The lastest code is in the Git. Looks like the ATmega32U4 is fast enough to relatively easily run at least a single Sine effect with all directions and such even when using full floating point calculus and no LUTs for sin(). But it is getting a bit tight and it certainly cannot run 10 active Sine effects in parallel if you want to update all forces every 1m while still be able to handle all joytick position reading and other USB protocol details. Of course, you could really divide the force calculations into multiple 1ms cycles (of reading joystick position via USB) and thus, allow for more parallel effects to run even if their math takes longer than 1ms in total. I don't think anyone would be even able to feel the difference (especially thru all kinds of motor and real world inertias) even if you would calculate only some effects every 2ms and other effects every other 2ms. But yes, as someone just mentioned here a couple of posts ago, optimizing for speed using a simplified sin() (LUT) and switching to integer math only will come handy at some point of development.

I saw your design images earlier, but now you've actually printed and constructed a physical version. Nice. Any estimates on how much load, wear and tear it will take when printed with 3D printer plastic? The bearings seem to take the most wear off the plastic but the place where motors are attached to the axis could take some beating? Ah, yes. The code does look a bit familiar. Good that you have found some use for the earlier work. I have branched the adapt-ffb-joy code to an experimental branch called "direct-drive" which you can see here: https://github.com/tloimu/adapt-ffb-joy/tree/direct-drive It now has a working spring effect and auto center spring, but for other effects, just empty place holders. The code is structured to separate the FFB calculations ("ffb-abacus") so that it could be easily tested separately and ported to other projects too, if you may. I could see potential for us to share that part of the code at least. The USB side and the actual low level motor control (including hardware dependent impulse response and force linearization compensations) can still go on their own directions easily.

Hi, I would be interested in getting into the software side. I have the tools, basic hardware and even some experience to go with. And, of course, as a flight simmer (is that a word?), motivation too. I dug out my old project (adapt-ffb-joy - I think someone referenced it in this thread a couple of years ago) and wanted to improve the MS Sidewinder's FFB effects (the GamePort version) by bypassing its obscure FFB firmware with code running in Teensy (2.0) and controlling its motors directly with a simple L298N h-bridge. If that would work well, most of the FFB control code should have a lot in common with more ambitious hardware (like seen in this project plans) too. Now, I stumbled into this project just recently. And, it seems like your path is taking a lot of parallel directions and seems very interesting. Is there some project page with the designs, code etc. in some Git or elsewhere or is this forum thread (phew! this is a looong thread you got here) the only way to the info and interaction?