I'm an iOS developer. What would people want in an ecodriving app?

[gone-ot]

...TORQUE can be backsolved from HP and RPM and VE

...it's the MEP number that's gonna be the "bear."

[gone-kl]

social integration for challenging fellow ecomodders and hypermilers with potential built in for possible facebook updates or twitter feed updates when "milestones" are achieved. You don't have to take it to that level, but that's what people are looking for in an app these days.

if I were you and I wanted to make this app stand apart, I'd make it free, but with unlockable features either through IAP or by inviting other people to download the app. the unlockables don't need to cripple the app, but just add some neat functionality or customization. Of course, I have no idea how far you were hoping to take this app...without some of the above though, you're just another forgotten app in the hundreds of thousands of other apps.

[dcb]

familiarization with obd would be a good start, there is a Load pid. screw the social whizbang stuff without covering the basics.

[NateSchiffer]

Originally Posted by euromodder

An extensive hypermiling feature set will sell better to the ecodriver's niche-market - but we're below the 1%-ers

This is true, but I want to see what can be done if we really focus on ourselves. Part of it is scratching my own itch, certainly.

Originally Posted by euromodder

The internet connection isn't always on or working though.
Don't fall into the developer's trap that the 'net always needs to be working for the app to function properly

Sure. There needs to be fall-backs, if not because 3G is unreliable, then at least because I want it to work reasonably on an iPod Touch.

Originally Posted by euromodder

Must haves :
- logging
- high frequency OBD polling, i.e. realistic measurements updates.
- % time and distance idling
- % time and distance in which gear

Of those, the only thing that presents a real challenge would be high-frequency OBD polling. How high is sufficient? I would guess something like 1/5th of a second would be reasonable. Would you agree?

Originally Posted by euromodder

CdA is relatively easy to find, but Crr ?

My understanding is that a coast-down test will give you both -- CdA as the "m" component and Crr as the "b" component in y=mx+b.

Originally Posted by euromodder

You could maybe built a feature that grabs the required time/speed data and calculates the drag ?

You're reading my mind, euromodder.

Originally Posted by euromodder

You'd need to have the topography of the road ahead, actual vehicle weight, RR, ... this would get complicated very quickly.

I was just imagining the *vertical* rise.

Of course, there's another (possibly better) way to do this -- exploit the "critical points" that we make during our routes. You know: "Passing this sign I need to go 22 mph to juuust reach the stop on the hill." Put those in somehow, and then give feedback on the best time to EOC, for instance.

Love all these great ideas! Thanks, eurorider.

[NateSchiffer]

@Old_Tele_Man & dcb: How do you get horsepower from OBD? I saw the load PID, but the units don't seem to make sense. It's just giving a percent. Is this power output as a percent of the maximum delivered horsepower? Or maximum torque? In either case, how do you find the absolute numbers?

Also @Old_Tele_Man, what's VE and MEP? Do you mean MAP?

I would be thrilled if I could get a horsepower (or torque) figure directly from the ECU.

@micman: Social stuff would be neat, but later. I'll check out the Twitter integration in iOS 5.0. Does anyone know if there's an API for Ecomodder's fuel logs?

[gone-ot]

Volumetric Efficieny--how much "air" the engine really inhales vs. it's theoretical volume.

Brake Mean Effective Pressure--theoretical constant pressure that produces the power (lookup HP and P·L·A·N).

MEP = 150.8 × T / D

...where:

MEP = mean effective pressure, psi
T = torque, lb·ft
D = total piston displacement, cid

...note: mechanical efficiency = BMEP / IMEP ...there's a difference.

[NateSchiffer]

Forum ate my post, so here goes again. Just wanted to give a quick update:

My GoPoint GL1 came yesterday! It's smaller than the USB OBD2 adapter I got on eBay, around 2" long. The dock connector "clicks" in place, which is nice. It's put together with torx screws, so maybe I'll crack this baby open and post pics.

Also I have a 2010 Prius to test with! Once I get the prototype a little more polished I'll put it on the iPhone 3G and maybe put up some videos.

As far as the app, here's where my head's at:

If I learned anything from the brainstorm, it's that everyone wants something different. So what if, instead of carrying down the One True Dashboard from on high, I made something that anyone can customize? What if designing a custom dashboard for your car was as flexible as a webpage? The iPhone supports HTML5 Canvas, so you could make nice looking "real" gauges. Or go minimalist, like the SG does. Want a BSFC map? You got it! Roman numeral odometer? Sure! Make one of these? Why the hell not?

Not everyone codes, but most people can drag-and-drop. So what if the coders contributed to a "library" of gauges that are available to everyone?

Would anyone be interested in such an app?

[dcb]

Originally Posted by NateSchiffer

Would anyone be interested in such an app?

Only interested if it is open source. No ipad/iphones here so algorithms only thing of value to me.

[orange4boy]

"So what if, instead of carrying down the One True Dashboard from on high, I made something that anyone can customize? What if designing a custom dashboard for your car was as flexible as a webpage? "

Sounds good to me. My favourite gauge so far was the homebrew "graham scanner" for the prius that you could customize with a few choices of whatever info the obd was spewing out. It had a very clunky interface which was the only bad thing about it but you could data log and check out specific things you might be interested in on any given day.

You can be sure that the prius geek crowd would be in.

Any chance of error code reading and clearing thrown in there?

[NateSchiffer]

I take it you mean this? Looks great! I definitely want datalogging, just maybe not in the first release.

There are free apps that do error code scanning and clearing, so it's not a top priority.