Off Topic: Cruise control mod?

hi Eric,I too have an after market cruise control. What I have been wanting to do is modify it with some presets for different speeds. Don't know why the manufacturers don't build them that way. Probably some liability issues. Ivan Vegvary

It's almost certainly pulses. You probably want a circuit based on a phase locked loop (look for a circuit with a 4046 chip in it).

There may be too much delay in the PLL for your cruise control to remain stable -- it kinda depends on how many pulses per second you get at your desired speed, and how the cruise control is setup. Try & see.

The cruise on my 2004 Suburban works above 25 mph. And you're right, it's handy. Drives the speed demons nuts when I go the speed limit through the subdivision.

So they're out there.

Pete Keillor

Didn't you mean this?

But seriously, these pulses are likely to be pretty slow, and it ought to b e a piece of cake to do this with a little microcontroller. An arduino ough t to be able to handle this easily, if you're not prepared to start from sc ratch. You can get everything you need at Radio Shack, even (glad to see th at they're carrying some actually usable stuff again).

If it does turn out to be an analog signal, you can do that with the microc ontroller as well.

I drive 15 in my neighborhood, which is posted 25; I prefer a certain quality of life, and over time I've found most of my neighbors do, too.

As to the 35MPH lower limit to most cruise controls, I have that on my vehicle as well. My assumption is that it is designed to force people (who are, in large, idiots) to pay attention when driving around town, where there are obstacles which do not exist on the open road.

Jon

It's also possible that the 35MPH lower limit is because at lower speeds, we tend to be closer to other cars (or pedestrians), and should the system fail in a "full speed ahead" mode, there'd be little time to react before damage was done.