Not to be confused with the ECU...

Hydroxy Technologies sells what they call a VMU (Vehicle Management Unit, http://www.hydroxycorp.com/shop/item.asp?itemid=33), & not to try to cut in to their sales or anything($439), I'd like to try to build one. They have Youtube videos as well (search vmu hho). It appears to me they have a small CPU with a touchscreen controlling an interface box that would more than likely be mounted somewhere under the hood. It has MAP/MAF sensor control, PWM, & O2 parameters. As of now, they are the only thing like it I've seen.

I'd like mine to do all that plus take input from the vehicle's OBD, & be able to display those parameters. I think the VMU can even turn the HHO generator on & off. That's not as important to me as being able to see how things like how the O2 sensor readings change from HHO off to HHO on. You could even use those readings to write algorithms to adjust them as needed.

One other thing I thought could be controlled would be a PWM being adjusted for such things as amps & temperature, since these two essentially define HHO output. You could have the amps increased while cold, then back off as the unit heats up, for example.

Now, I do have some electronics background, but it's been 25 years since I have even remotely been involved with it. Except for building around 5 home computers over the last 10-12 years. I think the interface box would need a PWM, EFIE, & other sensor inputs, with A/D & D/A so the controller could receive & output data. The question is, can you use some of the designs currently offered on the net, just modified slightly where the variable pots make the changes with D/A converters?

I have been looking into the the possibility of using a GPS unit as the CPU control box. They are all pretty much just little computers, I'd just have to be able to connect the interface(s) to it. In researching GPS's aftermarket programability, the Tomtoms (or at least some) have open source programming. (http://www.opentom.org/Main_Page) And, having the GPS inputs readily available, more accurate MPG calcs may be a reality.

I'd be interested in hearing what anybody here thinks about this. I may need programming/interface advice, for anyone who is a tinkerer like me) I may be in way over my head, but even if I just had a readout of OBD data, I feel like I could make more intelligent desicisions about manual EFIE and/or PWM adjustment. Yeah, I know about the $160 scangauge, but wouldn't it be cool have the data presented graphically (& in COLOR)... without an OBD interface that needs a laptop? (I don't have one)