SparkFun Forums

[Zrages]

I,m am building somewhat of a car pc and i,m stuck when it come to my five speed manual transmission.What I am trying to
to do is have a system that can sense what gear the transmission is in from only the shifter its self.
Some ideas I had in mind was a reed switch and a accelerometer but am not sure if these are the best sensors for the job.
My end goal is to have a visual indication of the gear my car is in from an Arduino using the best most suitable sensor for the job. I'm kinda new to Arduino and own a few really awesome books so any input would be helpful.

So the question is what is the best most suitable sensor?

[fll-freak]

I am no car expert, but I think you will find that there is a linkage from the H shifter to the transmission. This linkage is likely your best attack point. A linear pot might work, but trying to find one that will need the dirt and grime might be hard. I would likely tie a small super magnet to the linkage and set up a few reed switches of Hall effect sensor at appropriate points to determine where the linkage is.

[alandsidel]

I,m am building somewhat of a car pc and i,m stuck when it come to my five speed manual transmission.What I am trying to
to do is have a system that can sense what gear the transmission is in from only the shifter its self.
Some ideas I had in mind was a reed switch and a accelerometer but am not sure if these are the best sensors for the job.
My end goal is to have a visual indication of the gear my car is in from an Arduino using the best most suitable sensor for the job. I'm kinda new to Arduino and own a few really awesome books so any input would be helpful.

So the question is what is the best most suitable sensor?

As the other poster suggested, hall effect is your best bet, and you're going to have to program some "wiggle room" into the sensor.

I know you won't like this part either, but you are going to want it as close to the actual input selector on the transmission as possible. Between the bushing and the shifter there will be anywhere from three (RWD) to a dozen (FWD) bushings that get very worn out over time. Once they're completely worn you can tell, because you can wiggle the shifter around a lot when the car is in gear.

At that point, everything in the linkage is moving around a lot and the position of any part is not predictable over time. The farther you are from the transmission, the more bushings between the sensor and the input selector, and the harder this is going to be.

Do you care about this only when you're driving, or also when you're stopped? If it's only when driving, you can figure it out by tapping into two existing car sensors (RPM and speedo) and using a lookup table that holds your gear ratios.