segment gauge

[steveo]

really i think it was just sampling with arbitrary intervals that was the problem. i just changed my strategy so speed sensor polling happens in a tight loop for >50ms. there's a lot of dead air while displaying stuff.

the only reason i wanted to catch every sample rather than overall frequency was a total pulse accumulator so i'd have a perfect odometer, but i'd gladly sacrifice that so i don't loose speedometer precision at high speed.

i'll just calculate a rough average meters per second for an interval and feed the odo/trip accumulator with that, should be accurate enough.

[steveo]

just tested this:

http://yaab-arduino.blogspot.com/201...log-input.html

using interrupt driven input gives you much faster sampling and you can multitask (the processor is still available while the ADC is processing, the analogRead() function just blocks until it's finished)

actually dont think i'll need it, but for other projects, will come in handy to be able to sample at much higher rates.

[steveo]

it works pretty well

the cable between the ardunio and the display, i just chopped an old usb cable.

i ended up going with a really tiny sparkfun ardunio clone, as the uno wouldn't really fit in a container i liked.

external circuitry was really minimal, just a cheap switching power supply, a few lm7805s to step down the signal and high beam inputs to 5v, and two diodes for the signals so i didnt have to add a third regulator.

indicator logic: uses the first digit for signal (S) and high beam (H) (alternating), second digit for neutral (n) or the hundreds of speed (100+kph you aren't going to be in neutral, hopefully) and the last two digits for speed only.

it does FI light and oil pressure too, displays 0IL or ECU alterating with the speed/indicator display when these errors occur

inside, it's really hacky and circuit boards are held together with silicone, but i think it'll live.

speedo seems really accurate up to insane speeds, calibrated with GPS

[DavidBraley]

Looks good! I love how bright that display is. :)

[39 delux]

Been toying with the Arduino a bit but have hit a brick wall. No matter what I do with a sketch when I go to compile "file not found". Great potential with this unit (or Raspberry Pi) that can bring cheap fuel injection, displays and transmission controls.