MKIII throttle features ported to compact collective

A couple of cool features have been ported to the compact collective:

  • DCS Huey compatibility mode
  • joystick button press on throttle cutoff
  • secondary axis stabilizer – adjustable noise filter for potentiometer driven axes
  • bug with incorrect button modifiers fixed for both pedestals

I think we can safely say, that with these features added, the compact collective is now complete. Here’s how it behaves by default at the moment:

  • DCS Huey compatibility mode is turned on by default. That means, that when advancing throttle from full-right (closed) position, up to idle detent mark, keyboard button for throttle up key will be pressed (PgUp by default). After the mark, regular axis movement will be performed. To close the throttle completely (past the idle stop detent) you need to press the right push button on the compact collective head, which is set up as an IDLE REL button. This button won’t be pressing any joystick buttons when configured as IDLE REL button. If you don’t press the button before advancing the throttle past the idle stop mark, the virtual grip will stay at flight idle. You will have to move the grip back to the detent, press the IDLE REL button, and then close the throttle again.
  • joy button press on throttle cutoff is turned on by default – that means that if IDLE REL button has been pressed before closing the throttle, a joystick button (3 by default) on the collective joystick (note that, not the head, but the collective!) will be pressed when the throttle will reach full-right position. This is very useful for XPlane helicopters (like DF 407, for example).
  • secondary axis stabilizer is a very simple “digitizer” for potentiometer-driven axes. It allows for setting the minimal axis movement required to register a change in an axis. This kills the jitter completely and does not affect precision for stuff like throttles, zoom, and other secondary stuff where super precision is not really required. Can be set up on per-device basis depending on your potentiometer state =)

You can download the latest firmware from simchair4_software repo on GitHub.

Compact collective with VRMaxII pedestal checkride

Here’s my first attempt to film a complete short flight between airports for a demo of the hardware, and it hasn’t gone without some errors and weird maneuvers ofc lol (because 3rd take lol!), please excuse that =)

In the first part of the video, I show hardware up close, and then fly from 4S2 Ken Jenstedt to 35S Wasco state in XPlane 11 using KLICKITAT VOR for navigation, mainly to show the new radio panel of VRMaxII pedestal! =) You can also see how fun it is to fly with real VFR charts in PDF using Avitab plugin, rather than with a built-in map! Puts some extra workload on you during long (boring) straight flight legs =)

With a moving map, you only look out of the window because you’re bored. Without it, you have to constantly look for scenery highlights to check your position! I’d say try it, and you won’t regret!


Somehow so far I haven’t talked about pedestals yet except for a brief introduction in a recent video, so let’s look at the latest updates =)

At the moment, there are two pedestal devices available: the simple pedestal, and the VRMax II one. These devices are actually very similar to each other, one being the more advanced version of another:

Simple pedestal
VRMax II pedestal

One of these, in my opinion, is a must-have option for Simchair collective. Why? It allows you to use your left hand for operating switches, knobs, and other stuff in a helicopter, thus eliminating the need for letting go of your cyclic. When I first tried the simple pedestal, it felt like a major improvement to the flying experience.

I’ve been gathering feedback from the community for a while, and there were 2 popular opinions:

  • 1 knob for everything is cool – you can’t cover all of them anyway
  • having more knobs is better – on some helicopters, there are knobs that are placed in a way that looking at those would still be distracting

I, personally, liked the VRMax head and wanted to make something that will take its pros while dealing with its issues. So the VRMax II pedestal was born – which uses the straightforward and compact design of a simple pedestal while also adding the comfort of having 4 separate knobs for frequently used functions – and has a really nice rotary switch to map these knobs to 8 joystick button sets (of 10 buttons each – 2 per encoder + 2 green push buttons). An important thing is, it’s designed to be mounted onto the base of the lever, and that means, you can use it with a motion platform without worrying about its weight =)

Initially, I thought using a rotary switch might be confusing, but only until I mounted the device to the collective and tried selecting modes with it. The switch turns 3 clicks to the left and 4 clicks to the right, the shape of its knob can precisely tell you what position the switch is at now.

For the simple pedestal, its assembly manual, software, and model files are available, for the VRMax II one, radio panel firmware is in development at the moment. It’s model files, however, are already available in simchair4_models repo on GitHub.

MKIV stackable master controller enclosure

I am happy to announce I’ve just pushed the final part of the controller to the repo =)

The new device looks better than the MKIII one, you can mount it to any 10x20mm rail (the default option is to mount it onto the cyclic base one). With the new software, you can put the needed number of these thingies next to each other, using the standard short blue USB wires that come with Chinese Arduino clone boards and a USB hub.

Standard setup with a compact collective, equipped with a pedestal, requires one master controller, but for stuff like VRMax, you may need two of them.

Internally, its the same thing as MKIII but with an added MCU reset button (which was needed occasionally when there was something wrong with the firmware). The button is connected between RST and GND of the board.

Stay tuned!

Simchair MKIV in action!

I’ve been able to make a couple of videos to show new devices in action, with simple pedestal among them! I really liked it, for me it solves the mouse-in-VR problem perfectly. It can be easily found while wearing the helmet, and position of controls on it allows for comfortable operation.

In the first video, I talk about MKIV line, the new firmware, and show the new collective base, the pedestal, and a simple collective MKIV lever body parts.

The second one is an extension to the 1st one, in which we can see how the new hardware and software work together in flight. This time controls were captured with a separate wide-angle-lens camera!

Simchair MKIV firmware is now flyable

I have ported essential stuff to the MKIV master firmware today and had a few minutes to make a couple of circles around the runway to test it. At the moment, we have the support of the following peripherals in the firmware:

  • compact collective (at the moment MKIII simple collective- axes only)
  • simple pedestal
  • cyclic base (MKIII/MKIV)
  • B8 grip
  • pedals

All special stuff like force trim, sensitivity switching, etc, works already. For now, each device shows as a separate joystick. Here are a few key features of the new firmware:

  • the user specifies connected devices manually by uncommenting corresponding lines in “device_definitions” tab
  • software is now modular by design – every device can be disabled or enabled separately
  • controllers are now infinitely stackable – user can choose what device goes where, the only limitation is – cyclic base, grip, and pedals should belong to the same controller for special stuff to work!
  • an infinite number of devices can be included in the firmware thanks to the new modular design
  • custom devices (mods, variations, etc) can be added in a way so those won’t interfere with firmware updates!
  • no more limits on axes and buttons – if we need more for some particular device, we just add another controller! All devices have unique joystick ids that will provide at least a certain order of controllers in games. That means, e.g. a throttle quadrant plugged into controller #3 will still appear in joy.cpl with e.g. id #5 – below other devices plugged into controller #1, that e.g. have ids #6 and #7.
  • minimalism – joysticks only have what’s needed now instead of trying to fit stuff into 3 predefined joysticks, e.g. pedals only have 1 rudder axis and nothing else. Among other things, this helps with identifying devices. It results in some overhead, that may lead to additional controllers needed. I may unite essential flight controls into 1st joystick (axes only) while keeping the rest of the stuff separate.
  • the code is mostly cleaned and reformatted for better readability
  • it feels great in flight! =)

Simchair MKIV firmware news

The new MKIV firmware is now live! So far it supports the simple collective (MKIII one) and a new “simple pedestal”, the name will most likely change =)

The most important part about the new software is, it uses a different approach to how devices are set up. If MKIII software was autodetecting devices on startup, MKIV one requires a user to define what devices to expect. This approach allows for saving both RAM and flash memory, and thus we may even end up using a single Leo board, while the library of supported devices can grow infinitely!

The only limit is the number of devices actually connected simulatenously!

Another important change is how joystick objects are used. In MKIII, there were 3 joysticks with a large number of buttons, and all devices used the same set of buttons. In MKIV, different joystick objects are generated for different devices. Some of them will share joystick IDs (e.g. collective levers), others will be unique (e.g. collective heads).

Other devices will be ported into MKIV as soon as possible, starting from MKIV gimbal, B8 grip, and pedals.

More cool stuff is on the way, so stay tuned!

MKIV collective base is released!

I am glad to announce the completion of the 1st manual of Simchair MKIV line. The new line of hardware will take a Linux-like approach – we will have separate compatible modules that can be connected together to form a lever of choice.

The new base is epic, so from now on, the MKIII one is obsolete =) It is fully compatible with all MKIII lever bodies, and you can safely use it with those if you’re building the lever right now.

The first lever body to be released will be the compact collective – a motion-platform ready compact solution with integrated head. An interesting thing about it is that it supports the pneumatic mod, but does not require it! Also, it doesn’t need the counterweight, and that’s important with all lateral loads and shake that can be present when using the lever with motion platforms.

STL’s and sources can be downloaded from the new simchair4_models repo.

First Simchair MKIV collective is ready for testing

I have just finished building the 1st MKIV collective base, and can say it’s great!

Not only its much stronger and more precise, but has a built-in mode switch that can be used for various functions in the software, 2 Ethernet sockets instead of a cable with a plug, and can be flashed through any of these sockets – with any USB-UART board! For cheaper boards without the DTR pin it has an MCU RESET button, that allows it to be flashed with manual reset in the process with stuff like PL2303 (which I no longer recommend using, just buy an FT232TL based board which is roughly the same price but installs drivers for itself and resets ProMinis automatically).

I actually liked ” live ” flashing and calibration more than I thought I would. The lever body itself is the first one intended to work with motion platforms – it’s strong yet lightweight, so lateral loads should not be a problem for it. The head also features the same set of buttons as the Huey-style head – but can be operated without the pneumatic mod.

Now, let’s look at what has changed. The new base has its Pro Mini connected in the following way:

  • Mode switch left pin -> Pro Mini pin 2
  • Mode switch GND -> GND next to RST
  • Mode switch right pin -> Pro Mini pin 3
  • MCU RST button -> between RST and GND next to it
  • SS495A1 pin 1 -> THR POT left pin (on the left when the lever is mounted as usual) VCC cable tie <- Pro Mini VCC <- Ethernet sockets pin 1
  • SS495A1 pin 2 -> THR POT right pin -> GND cable tie <- Pro Mini GND <- Ethernet sockets pin 2
  • A0 -> SS495A1 signal
  • A1 -> THR POT signal
  • A4 -> SDA cable tie <- Ethernet sockets pin 3
  • A5 -> SCL cable tie <- Ethernet sockets pin 4
  • Collective head I2C cable -> VCC, GND, SCL,SDA cable ties
  • Pro Mini Rx -> Ethernet sockets pin 5
  • Pro Mini Tx -> Ethernet sockets pin 6
  • Pro Mini DTR -> Ethernet sockets pin 7