[pjmoreland]

I added the vacuum sensor logic to the code this evening and went for a test drive. I made a couple of tweaks to the trip points and settled on 12 inHg for the lock level and 6 inHg for the unlock level. I have to say this controller is working quite well.

1) The TCC locks at 50mph and then unlocks at 45 mph. This means the engine never gets lugged by the TCC when coasting down to low speeds when driving around town. This was the main problem with my earlier dual vacuum switch setup.

2) At speeds over 50mph, the TCC unlocks if I press down on the gas pedal enough to drop the vacuum level below 6 inHg. This feels like a natural level to unlock at since the gas pedal is pressed fairly far down either to pass someone or to go up a steep hill.

3) Also at speeds over 50mph, the TCC will lock only if the vacuum is above 12 inHg, which is fairly light on the gas. This allows acceleration onto the freeway without locking the TCC until after you're done accelerating and backing off the gas.

4) I have the vacuum sensor hooked to timed vacuum, so it drops to 0 inHg when coasting. This causes the TCC to unlock when coasting. it then locks back up immediately after reapplying the gas.

I'm planning on adding a feature that allows the TCC to stay locked longer if the gas pedal is pressed down very slowly which would happen frequently when trying to maintain speed on a hill. The code will calculate how much the vacuum level changed from one reading to the next and use this as an indicator of how quickly the gas pedal is being pressed down.

This controller is to the point where it deserves to be mounted permanently in my truck.