There are many excellent DIY devices and rigs out there that can give you extra buttons, enhance emersion, help with accessibility or do the thinking for you in highly stressful races.  Here is a list of items I have used, reviewed and found over the past few years that you may want to consider building.  As I continue down the DIY path, I will update this article with all the new and wonderful things I build along the way.

iRacing PitBoard [for iRacing]

There are many things I can not do and one of them is calculate how much fuel I need while racing other cars out on track.  Sure, I probably should be more prepared and do enough practice before a race to determine my fuel requirements, but due to safety cars, drafting and strategy, sometimes you need to do this on the fly.  The iRacing PitBoard by Brock Cremer is a device I have built and is now something I can not live without. Active development of this device has been going on for a few years now and if their website is to be believed, almost 1000 people have spent the $15 or so dollars on the Arduino and screen on eBay to build the device. The website says that "the iRacing PitBoard is a small Arduino based device designed to give you live up to date information about your fuel requirements in any session online or offline including races that requires one or more pit stops. It works with both timed and lap based sessions up to 24 hours in length", which in my experience, is exactly what it does.  More recent development has introduced automated stopping of re-fueling which means that it does all the thinking for you and tells the pit crew to stop putting fuel in the car when there is enough to finish the race.  Zero touch pit stops sounds and is delightful to me. The community data from all the connected devices also updates the website and shows fuel burn figures for almost every car and track combination.  So even if your not into this DIY project, there is still some benefit to checking out the site.

Reading through the forums, there have been some people out there that have had some issues with reversed text on their screen or connectivity issues after recent Windows 10 updates.  The community is very active, as is the developer, who is more than happy to help resolve any issues you may have.  Brock, the developer also regularly asks for ideas and features that the community wants to be implemented, so there is little risk of this becoming unsupported in the short term.

More information can be found on the iRacing PitBoard website and the iRacing forum.

Cost: ~$15
Build difficulty: 3/10
Effectiveness: 9/10

Analogue handbrake by amstudio [for all games]

What happens when you buy a cheap "real" handbrake of eBay, an Arduino Pro Micro, a slide pot and some parts found around the house, well you come up with an analogue game controller with 1 axis in the shape of a racing handbrake.  This is one of those devices that I thought I needed, found a really good tutorial, built and spent the rest of the year telling everyone I could that they should build one.  The tutorial video on YouTube walks you through converting an after market hydraulic handbrake suitable for a track day car into a pot driven USB game controller.  The removal of un-required parts is rather easy with the difficulty in this build being shaping and building an end plate and the flashing of the Arduino code.  This is only tricky because you can brick your Arduino if you don't install the appropriate board driver.

This device works exceptionally well in iRacing (Global Rally Cross) as well as Assetto Corsa and will work with any game as it is seen by the computer as a single axis game controller.  Given the left over pins on the Arduino, you could also add additional buttons if you wanted to spend time updating the Arduino code.  At the time of writing this, the tutorial video has over 232,000 views, making it a very popular source for a DIY project.

Cost: ~$45
Build difficulty: 5/10
Effectiveness: 7/10 

Extruded Aluminium Sim-Rig (aka 80/20)

Now this is something that I have yet to build as I have a commercial sim rig, but given my love of tinkering and the idea of having a unique and perfect rig for my needs, the idea of building one from scratch often comes into my mind.  In fact, I only found this because I was wondering what designs were out there.  This buying guide is a very good source of knowledge to start.  It is full of pictures and information that can help you get well on the way to building your own custom sim rig.

Cost: Depends on complexity and availability of materials (~$1.25 per foot/metre)
Build difficulty: 6/10
Effectiveness: 7/10  

iFlag [for iRacing]

DIY: Check
Open Source: Check
Cheap: Check
Useful: Check

Parts
Arduino UNO board or any 100% UNO compatible clone
Colors Shield by Itead
60mm 8×8 LED Matrix by Itead

This is a device I built simply because I am colorblind and it helped me see the difference between yellow and green flags in iRacing.  iFlag or iRacing Flashing Light Awareness Guard is a "race marshalling light board for iRacing.com motorsport simulation. Arduino-based LED matrix displays racing flags in a truly noticable peripheral vision fashion making it literally impossible to miss any flag like yellow, blue or safetycar flags. Additionaly includes optional useful signals like start lights on the grid and more".  This is a great little device that just works and does what it says it will do.  There are a number of 3D printable cases specifically designed for this device if you go searching, and I did end up printing one for myself.

Cost: ~$35
Build difficulty: 2/10
Effectiveness: 8/10  

Comment