When you’re driving a car with a stickshift, it’s pretty easy to keep track of which gear you’re in. That can be a little bit more difficult on something like a motorcycle with a sequential shifter. [decogabry] built a neat gearshift indicator to solve this issue.
An ESP32 devboard is used as the brain of the build. It’s paired with an ELM327 dongle over Bluetooth, which is able to hook into the bike’s ODB diagnostic port to pick up data like engine RPM, wheel speed, and coolant temperature. The first two factors are combined in order to calculate the current gear, since the ratio between engine RPM and wheel speed is determined directly by the gear selection. The ESP32 then commands a Philips ZM1020 Nixie tube to display the gear, driving it via a small nest of MPSA42 transistors. A separate self-contained power supply module is used to take the bike’s 12 volt supply up to the 170 volts needed to run the tube. There is also a small four-digit display used to show status information, RPM, and engine temperature.
Notably, [decogabry] made this build rather flexible, to suit any bike it might be installed upon. The gear ratios are not hard coded in software. Instead, there is a simple learning routine that runs the first time the system is powered up, which compares RPM and wheel speed during a steady-state ride and saves the ratios to flash.
We’ve featured projects before that used different techniques to achieve similar ends. It’s also interesting to speculate as to whether there’s a motorcycle vintage enough to suit a Nixie display while still having an ODB interface on board as standard. Meanwhile, if you’re cooking up your own neat automotive builds, don’t hesitate to drop us a line.
For years my daily ride (a KZ400) had a magneto and points. It did have a neutral indicator light, which I thought was a pretty nifty innovation.
Even now it sounds crazy to me that a bike has an OBD port and a Bluetooth connection.
The bike doesn’t have BlueTooth, the ODB dongle does.
I’ll dispute his “most bike have OBD” claim. It was never mandated for bikes, so manufactured never bothered for the most part, Some larger bikes now have it, very few smaller bikes do, and even then it’s non-standard.
At best you might get a blink code.
Vibration and a Nixie may not ride well. Maybe the Soviet ones made for tanks and such might.
K.I.S.S. what’s between your legs while riding when it comes to visual distractions.
kiss… between legs… distractions… username checks out. :-)