Now, it’s been a shamefully long time since we’ve driven a car with a manual transmission, but as we recall it was pretty straightforward. It certainly didn’t require a lot of help with the shifting pattern, at least not enough to require a technical solution to know what gear you’re in. But then again, we suspect that’s not really the point of [upir]’s latest build.
Oh sure, it’s pretty cool to display your current gear selection on a little LCD screen using an Arduino. And [upir] promises a follow-up project where the display goes inside the shifter knob, which will be really cool. But if you take a look at the video below, you’ll see that the real value of this project is the stepwise approach he takes to create this project. [upir] spends most of the time in the video below simulating the hardware and the code of the project in Wokwi, which lets him make changes and tune the design up before committing anything to actual hardware.
That turned out to be particularly useful with this build since he chose to use analog Hall sensors to detect the shift lever position and didn’t know exactly how that would work. Wokwi let him quickly build a virtual prototype for one sensor (using a potentiometer as a stand-in, since the simulator lacked a Hall sensor model), then quickly expand to the four sensors needed to detect all six gear positions.
By the time his simulation was complete, the code was almost entirely written. [upir] also walks us through his toolchains for both designing the graphics and laying out the PCB, a non-trivial task given the odd layout. We particularly enjoyed the tip on making smooth curved traces around the oval cutout for the shift lever in the board.
The video below is on the longish side, but it’s chock full of great little tips. Check out some more of [upir]’s work, like his pimped-out potentiometer or his custom animations on 16×2 LCDs.
Continue reading “Arduino Gear Shift Indicator Finds ‘Em So You Won’t Grind ‘Em”





Simple machines are wonderful in their own right and serve as the cornerstones of many technological advances. This is certainly true for the humble lever and the role it plays in manual transmissions as evidenced in this week’s Retrotechtacular installment,
Next, we are shown how engine power is transferred to the rear wheels: it travels from a gear on the engine shaft to a gear on the drive shaft through gears on the countershaft. At low speeds, we let the smallest gear on the countershaft turn the largest gear on the drive shaft. When the engine is turning 90 RPM, the rear wheel turns at 30 RPM. At high speeds using high gears, the power goes directly from the engine shaft to the drive shaft and the RPM on both is equal. The film goes on to explain how the gearbox handles reverse, and the vast improvements to transmission life made possible through synchromesh gearing.