Hi everyone, I don't know how I've never found this site before but it's so awesome! I've never build robots or anything but I love this stuff and I think I will soon be addicted. I build custom classic cars and this stuff could be very useful. All that out of the way here's my question.
I want to make an actuator for my car's transmission that can stop at four different positions (Park, Reverse, Neutral, Drive). A lot of new cars are ditching the shift linkage and cables for fancy dials or buttons. I want that in my classic car. I plan to use a dial switch from a Jaguar or Land Rover (See pics) and I want the actuator to move based off of what postition the dial is in. In theory I think the wiring of the dial is pretty simple, power in and each postion completes a circuit to tell the actuator where to go. But I have no clue how to setup an actuator to recognize or use those signals.
Automotive Adaptation
Welcome to the world of robotics. There’s a TON of stuff you’ll likely start thinking of adding to your cars, from simple LED lighting effects to full onboard PCs with touch screen, automatic doors etc.
Regarding the transmission, keep in mind that most DC linear actuators are not automotive rated - you should absolutely factor in a method to manually disable it should something go wrong (loss of power for example).
I’ve (personally) never taken apart one of those automotive knobs to know what’s included - it’s likely either a rotational potentiometer or an encoder. You’ll need to research that or even buy one. It’s not too hard to create your own though. You’d need to choose a linear actuator with built-in potentiometer feedback (so it can stop at specific positions). On its own however it is “dumb” - you’d need a DC motor controller and a microcontroller. The microcontroller reads the input from the knob / dial / switch and converts that to a desired position - it sends the right motion command to the DC motor controller (speed and direction) and reads the linear actuator’s position to know when to stop. You’d need to create a PID control algorithm.
Microcontroller: https://www.robotshop.com/en/microcontrollers.html
DC motor Controller: https://www.robotshop.com/en/brushed-motor-controllers.html
DC Linear actuators: https://www.robotshop.com/en/actuators.html
Legal?
I don’t know where you live, but I have my doubts that your car will still be road legal.