[glavey]

I think I've discovered the reason guys who name bikes, cars, trucks, etc use female names... I was going to name by bike something really unusual, like... Bob. Then I realized if I was ever asked what I was doing all weekend long, I'll have to answer, "Oh man, I was riding Bob all weekend. He's a real screamer. I couldn't walk right for a while after getting off of him."

On a less sarcastic note, I took Bob out for a brisk ride today. About 50F, but with clear skies and sunlight to warm you up. I adjusted the clutch so I can actually start from a stop and not stall 5 times. I had read that the gearbox in this engine is quite smooth, but damn it really is. This bike is an excellent candidate for a quick shifter. I'm not sure if this is the correct terminology, but the gears are close ratio, meaning... for example lets say you are at 5000rpm in third gear, you shift into fourth and the revs only go down to... maybe 3700-4000rpm. Not a lot of drive line shock will happen going between those revs.

I have been looking for a wideband gauge that has the numerical AFR readout as well as a row/bar/graph/ring of LEDs that at a quick glance can give you a rough idea of what your mixture is. I could only find gauges with integrated sensor controllers for >$125. Nope, I already bought a controller and I'm not buying another just for a gauge. So I set out to make my own.

2 or 3 years ago, I made a dashboard for my scooter (pictured). Everything on it worked as it should (needles moved, numbers were displayed), but I had a problem with getting a reliable, clean signal for the engine rpm and the speedometer. I stopped working on it because I had one of those moments where you work hard on something, and in the end it was all for naught, combined with me not really riding it enough to warrant caring about it.

I dissected dashboard and preformed an display-ectome. I took out the 16x2 character display (blue rectangular display) and the two 7-segment, 4 digit displays. Organ harvesting done, I started trying to imagine what the gauge could look like with what I had to work with. The 7 segment display fit in the center of a gauge face I had (in a previous life, the gauge was for oil temperature on my scooter) with enough room around it to line the gauge face with LEDs.

I like the wideband gauges that have, from left to right, yellow LEDs for rich, green for stoichiometric, and red for lean. I wanted to copy that in my gauge, so I gathered some LEDs out of my electronics project box and glued them in a ring to the inside of the gauge face along with one of the 7 segment displays (pictured). I wanted to have two 7 segment displays and the LEDs, but the chip I am using to drive them can only do 2x 7 segment 4 digit displays (maximum of 8 digits) OR one 7 segment 4 digit display and the LED ring that I just glued in. I went with a 7 segment 4 digit display with the LEDs. I did have another driver chip in the scooter dashboard, but when I tried to de-solder it, I killed it.

After much soldering, gluing, and back-ache from being hunched over a desk, I got all of the LEDs and the display connected to an arduino nano and used a example program to test out all of the individual sections of the display and LEDs.



Success! Now, on to actually programming the arduino to make the display and the LEDs show meaningful data. After about 2 days, on and off (I'm not very good or fast at programming) I had working code that interpreted a 0-5 volt signal into 10.00 to 20.00 AFR on the display, and individual LEDs would light to indicate AFR within a given range (attached to this post, if you have the arduino IDE, you can just double click the afr.ino file to open it in the arduino IDE. If you don't have the arduino IDE installed, you can open the afr.txt file. Both filesa re exactly the same, just with different file extensions). Now that I had working gauge electronics, I had to cram and stuff them into the gauge housing. In the end I got everything in; the gauge face and everything glued to it, the arduino, all of the wiring, and a 5 volt step-down voltage converter. I plugged in the arduino using a USB cable and nothing happened and then I saw a small whiff of magic electronic smoke escape from the voltage converter. It appears that the converter was not able to have 5v applied to the output when there wasn't any voltage on the input side. I tried using a diode on the 5v output, but it was too late, the patient had died. Now I can either make a voltage regulator (it would get real hot inside a gauge case) or buy some different, better made voltage converters(like the one I used in the bluetooth case).

Thats about it for this post.