[Johan Beyers] built an elegantly simple Dog Speedometer project that uses a POV display to display a running dog’s speed without the benefit of an accelerometer. Using an Arduino (looks like it might be a D-love) and a line of 5 LEDs, [Johan] built a dirt-simple POV — 39 lines of code — that times out the flashes so that an immobile viewer sees the dog’s speed. How do you know your pup’s loping speed? That’s the beauty of this project.
Instead of putting all of the LEDs in a line, they are arranged in a V-shape. Because of this spatial offset, the patterns flashed out only “look right” at the right speed. Each number is flashed at a different speed, so you just look for the least distorted numeral.
[Johan]’s code does only what it needs to get the job done. The character data are stored in arrays that are played back directly to the pins of PORTD — avoiding most of the usual Arduino-style complexity with pin definitions and other foolery.
POV displays can be leveraged to add pizzazz to any project — this CD-ROM POV clock and this wind-powered POV weather station come to mind.
Aww, who’s a good doggy? Whoozagoodpuppy? Who’s gonna tear that thing to shreds when they bound away off-leash? You are! Oh, yes you are yousagooddoggy, you.
Super cool! (But it might need a case.)
And some smaller arduino type, not that one which is supposed to be on worktable.
If I did this today, I would, yes. When I did this (in 2012), I only had that one Arduino and I hadn’t built my 3d printer yet, so no case. It works very nicely to have the older-style arduino, since a stripboard shield is very easy to make for those.
Interesting project. Would be nice to see a video of it in operation.
I have a setup where I trigger it at a specific point while spinning on a lazy susan, which shows the concept. I just have to set it up, so expect that in the next few days.
I can’t really read the numbers on the photo version, so I fear I won’t be able to make sense of a video version either
He claims you can get a speed reading accurate to 1km/h – I’d like to see how he worked this out
I just eyeballed it :) Since I can see the amount of skew for each indication, and they are 5 km/h apart, I can make a pretty good guess. If needed, I can add intermediate lines to increase the visual accuracy. In practice, +-1km/h is easily achievable.
obligatory 555 comment — he should do it with a 555
That’s over engineered, one transistor to measure electrical activity in its gluteus maximus (bum) with a wire soldered to a needle and another one driving a led bar graph through a resistor network.
That’s too fancy, what you need is an anemometer driving a zeotrope calibrated to various speeds…
“D-love”? Due-mila-nove. 2009. It’s the Arduino 2009. It’s not hard. I don’t speak any Italian at all and it’s still obvious.
I figure it’s just how the cool kids refer to the old-school Arduinos these days. You know, like when someone’s got a Raspi project, and you’re like “I coulda done that on a D-love.” Nerd slang 22 lyfe!
Finally got a video made: https://youtu.be/dlEagnvZ-Sk
Just pinging to get notified of comments.
It is CUTE. I wonder how many G’s she pulls in those turns and what her caloriemeter reports…