Motorcycle computer

Hackaday writer of yore [Will O’Brien] has been working on this hardware for his motorcycle. Speed, voltage, gear, and temperature data is displayed on a 16×2 character LCD. The speed is pulled from the bike itself and the gear is calculated by comparing engine RPM to wheel RPM. He’s using the popular DS1820 1-wire temp sensor along with an Arduino to pull everything together. At this point he estimates there’s about $50 worth of parts, but that can be reduced by etching a board and just using the necessary components.

21 thoughts on “Motorcycle computer

  1. This is a great idea, its nice to be able to glance at what gear you’re in on a motorcycle, and he has the right idea talking about isolating parts. 10 points for using the Arduino to PROTOTYPE…

  2. it’s a nice project, but after almost 10 years riding my bike all year long, I still don’t understand why there’s a need for “gear” info.

    Everything that can distract you from the road (beside the actual speed) is something that can severely reduce your lifetime.

    I would be much interested in some mileage infos to look at when I stand still at a stop sign.

  3. @ino
    That’s true, I didn’t even think of mileage, would be very useful to look at. It’s nice to see one of these projects for motorcycle though, versus the hundreds of car projects out there.

  4. Cool project, my only suggestion might be along the lines of what ino said, reading actual numbers can take your eyes off the road, which is always bad. I’d probably go for a small graphic lcd, where you could replicate analog needle gauges, I think they’re faster to read, as you’re not trying to read a number, but instead just looking at a position. iirc, this is why needle gauges are still used.

  5. I have one of these done with a PIC 16F877:

    Since then I’ve implemented coolant temperature using one of the ADCs. And I’ve plugged it into a real engine.

    I have considered gear indication by comparing speed and RPM, but decided it would be too flakey to be of real use, maybe I’m wrong on that one.

    Our screen is for a Formula Stutent car, which uses a CBR600RR motor. I’ll be posting another video using a real engine soon.

  6. Gear indicator? I guess if you’re deaf or senile that might be useful. Of course if you’re senile perhaps a moisture sensor for your Depends would be more useful.

  7. @ino: sure, any ol’ biker will say something like “i dont need no darn computer to tell me what gear im in”, but its the other useful stats and data that are of use, whether it be while driving or, as you stated, at a stopsign.

  8. If you’ve never caught yourself trying to find that elusive seventh gear, you haven’t ridden much. I’m working an this very same thing right now for my SV650, but the gear calculation method is slightly simplified. There’s actually a signal to the ECU that tells it what gear you’re in, so I’m tapping that and interpreting the signal to get the gear.

  9. Hey Andy.

    I have a ’07 sv650s myself. If you haven’t found it, there is a schematic over the gear resistors somwhere on

    Is there anyway to pull the data from the onboard ecu like OBD2 in cars?

  10. Woohoo! I was just planning on doing this myself.

    I have a 2004 Honda CRF450R (dirt bike) that I’m finishing up a dual sport conversion on to make it street legal.

    The bike had basically no electrical system whatsoever except for the ignition module (which I can get engine RPM from by counting the pulses), I’ve created everything myself (so far new stator -> voltage regulator -> small battery as a buffer -> lighting system).

    I’ve seen some aftermarket motorcycle computers, but, being an EE student at UT Austin, that’s just not good enough, I’m going to do it myself.

    I’ve got all the parts, just need to code it all up. The sensors will all be wired to a Silicon Labs C8051F340 MCU (it has USB for firmware updates and datalogging), which will collect sensor data and stream it out via serial. On the other end of the serial line will be my Android phone, which I will dock into the handlebars when I’m ready to go for a ride, and will have a cool UI. I’m also considering some anti-theft measures, to where the bike will only start if the phone is plugged in and sends the right “key” to the MCU, which will then enable the ignition system.

    Add in a stereo bluetooth headset into my helmet, and I’ll have my dashboard, GPS navigation, phone, and music all in one! Yay Android!

  11. I gotta chime in on the gear info. I can see the value of gathering the data – even if it’s not displayed. If you can store that data to memory, it could potentially be used if (God forbid) you’re ever in an accident. If you weren’t driving recklessly and the data is collected at a high enough rate, you could probably use the data to help your case. If you can show that you weren’t making aggressive gear shifts and your speed was within limits – that could really help prove whether or not you have partial responsibility.
    Personally I would opt for having a display – my bike shows very few metrics, so I’m pretty sure a little number won’t start a helmet fire.

    I really like this idea, it makes me wanna work something like this up for my bike!

  12. I, too, am a biker, I own a 79 CB750, which has little to no information other than speed and tach. I’m in the research process of designing a full ECU for it, and replacing the gauge pod with a digital version. Gear indication I could care less about really, but with an air-cooled engine, the temperature measurement would be quite invaluble. Speed and Tach, too, as my needles are warped and I’m pretty sure sticking a bit on the housing.

  13. Once I get things working well, I’ll put up code and schematics. Right now I’ve finally got most of the code roughly working, just working on debugging everything.

    For the gear indicator guys: I’m not too worried about the gear – I am worried about reprocessing the speed pickup and sending it the digital gauges I’ve retrofit.

  14. @Abbott:

    I have a ’79 and an ’80 F – love ’em both! For onboard ECU, etc, check out megasquirt. I’m doing that to mine right now, and Will’s project comes in at just the right time.

    I agree with the other posters – I’ve had more seat-time than I can fathom, so gear-position is pretty much useless WHILE I’M RIDING, but the *logging* portion makes gear-position much more desirable.

    @Tim with the CRF – dude, BAD-ASS BIKE! You’ve certainly got bigger cojones than I do though, putting your Droid on the bars. Then again, maybe your level of sanity off-road is higher than mine ;)

  15. Gear indicator can be dead on accurate if he simply swaps out the neutral switch for a indicator switch. Most bike makes have a low end (sportbike) and high end (touring) and they all use the same parts for the most part. replace the neutral switch with the gear indicator switch from a touring bike and you now have an absolute gear indicator.

    Most parts on bikes from the same maker are interchangeable. I swapped in a FJR1300 rear end onto a Royal Star venture and turned a old fart bagger into a sportbike (up to 750cc) killer. I make the kiddies on the Ninjas cry daily as I completely own them from light to light. I have trouble with the hayabusa bikes, but most of those are owned by kids that don’t know how to ride them so I still own them through 3rd gear.

  16. I am going to do something similar as a summer project.

    The things I will do different though:

    * GPS speed, will not be fast enough on acceleration but it’s ideal on highways because of the speed-cameras.

    * Outdoor temperature, I don’t care about engine temperature

    * RPM is guessed by voltage. Not accurate, but the only other option is to measure the pulses from my ignition coil, which is really hard to do.

    As for the device itself:

    -4 times 4″ 7-segment displays, much faster to read than an LCD display

    -8 large LEDS to display RPM.

    -PIC microcontroller because I’m not used to Arduino and I already have all the prototyping hardware I need

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