Hi all like the title says I have a automatic transmission shifter idea and just need some help with parts. So what this shifter hast to do is control a stepper motor with the help of two push button switches (one for upshifting like from park to 1st and one for downshifting 1st to park) this controller also hast to power 6 LEDs as part of the gear indicator system to let you know the current selected gear.
The power will come from a 12v source from the car battery which presents another question. I was planning on connecting this to a switched 12v source meaning it will not receive power with the ignition off. My question is would this be ok for the controller? Does the controller go through a lenghtly boot up process or is it instant on running the shifter program? Is there any other parts that I am missing for this setup?
Thanks for the help!
Taking a look at the spec sheet for the stepper motor I listed states that its max radial force is 75 N. This equates to about 16 Lbs of radial force. The transmission shifter lever requires at most 5 Lbs of force to shift to the next gear position. One thing that does confuse me is that this motor has 6 wire leads as stated in the specs howerver it also shows a wiring diagram for 4 leads so can this motor be set up with just 4 wire leads? If so then the Shield controller and the microcontroller I listed should also be sufficient for my purpose. For the switchs I was concidering a normal push button switch like thoughs found as a computer power switch. Fail safes will be built into the program to prevent the accidental shift into reverse or park while the car is in motion. I am concidering using a combination of both the right and left paddle shifters for this fail safe. The final failsafe is actually built right into the transmission which I can activate which also prevents accidental shifting into reverse or park. Another question I have is will this microcontroller power 6 normal LED lights with no other controller needed?
hi i’m a first timer too, i’m trying to do something similar where i want to put soliniods onto a manual trans and clutch (which the pedals and shift lever will overide when i want them to) and then use an arduino to controll the shifting. can any one point me in the right direction?
Could you please provide more details about what you are trying to achieve? What do you mean by “shifter”? Could you please include a link or some specs about this.
Also, the Arduino microcontroller will boot in roughly one second, after what, it will run its program.
That’s quite a project for a newbie… especially with the inherent safety issues. First suggestion is to start with a functional scale model using the right technology, then create a CAD model of the real setup using real parts. The other approach some people take is to build it without any design in mind. Some people with significant vehicle experience might try this, but giving over control of any major part of a vehicle to a custom / prototype system can be very dangerous. Can you provide a sketch or something as to how you plan to implement the system and where the stepper motors come into play?
We tend to stay away from providing suggestions where a life is potentially at risk if there is an issue with the design.
Step 1) Get an idea of the torque (force x distance) the motor will need in order to rotate the wheel you drew, which then pushes the rod to move the transmission. You will need a motor with position feedback.
Step 2) Add a safety factor of at least 1.5 (multiply the maximum torque value by at least 1.5)
Step 3) Choose a motor which can provide that torque
Step 4) Incorporate MANY safety features and fail-safe devices - you’re dealing with your life here.
Step 5) Choose a motor controller appropriate for the motor
Step 6) Choose a microcontroller and buttons
Step 7) Program the microcontroller to take input from the buttons and send the appropriate signals to the motor controller which in turn activates the motor.
It’s important to note that the torque is 125 oz-in, so the maximum force it can exert depends on how far away the force is acting from the center of the shaft (center of shaft to center location at which the force is acting). For example if the force is 5 inches away from the center of the shaft, the motor can only exert 125/5 = 25ounces (1.56lbs). There are two wiring diagrams in the user guide.
The issue I was considering was not being able to shift OUT of a gear while in motion or experiencing an electrical issue (or failure) with the board while you are moving.
If the LEDs consume 50mA or less, you can run them directly. If they consume 100mA or more (very bright), you should power them separately.
No, but you must understand that they are “hobby grade” as opposed to professional or industrial.
Interesting to have a thread about modifying actual cars for semi-autonomous behavior. We can try to help with the theory, but hopefully others here have actual experience doing it.
