app and hardware for iphone as motorcycle tach and speedo
Hi all, I am 100% totally new to this and have not looked into this aside from trying to find already existing apps, etc. hope I am posting this in the right place on the forum.
Basically, wondering if this is even possible, and if so, where to start? is it possible to make an app only for personal use or does it have to go through the apple approval etc to be able to actually use it on the phone?
I want to do 3 things for using the iphone as a replacement dash display on my non-ECU motorcycles. why? because it would be cool, it would aesthetically be very unusual and clean looking, and then the use of the tom tom app is right there in front of you as well.
1) have a dock that the phone plugs into where the old gauges used to be. this dock provides charging through the bike's electrical system and also the interface for the hardware that picks up the rpm and wheel revolutions for speedo.
- are there generic "docks" or the plug bit that plugs into the phone to buy? the rest is simply bracketry that I can machine up.
2) tachometer. this would require the hardware to pick up the electrical pulses at the coil signal wire (not the high voltage coil wire), this is a nominal 12v that goes to 0v then back to 12v. so probably pretty simple in terms of hardware, just a pickup wire, and ground wire, some kind of voltage limiter etc to keep the phone safe and then the iphone plug/dock thing. what kind of signal would the iphone be wanting here? can the iphone handle this type of analog signal or is the interface completely digital?
3) speedo, 2 ways to go here, one is to simply use the GPS information to determine speed. the other and preferred way would be to use either a hall effect sensor on the front wheel or something similar, this signal then gets piped up to the dock. so normally 12v and then a momentary 0v as the sensor passes for 1 wheel rev, then back to 12v.
So, have potentially 2 oscillating signals going to the dock that the app then needs to know how to interpret to then display the corresponding engine RPM and motorcycle speed.
For the tach, the user would need to be able to set how many voltage pulses per sec equals how many rpm, so that you could put in different multipliers for use on different number of cylinder motorcycles.
for the speedo, the user would need to be able to set some kind of multiplier as well, to adjust for front wheel diameter.
in addition, would be nice to add the neutral light indicator, blinker indicator lights into the unit, those are also simply 12v or no volt circuits.
thanks for any help or guidance or links to appropriate materials so I can start this process.
thanks!
dylan
Hi all, I am 100% totally new to this and have not looked into this aside from trying to find already existing apps, etc. hope I am posting this in the right place on the forum.
Basically, wondering if this is even possible, and if so, where to start? is it possible to make an app only for personal use or does it have to go through the apple approval etc to be able to actually use it on the phone?
I want to do 3 things for using the iphone as a replacement dash display on my non-ECU motorcycles. why? because it would be cool, it would aesthetically be very unusual and clean looking, and then the use of the tom tom app is right there in front of you as well.
1) have a dock that the phone plugs into where the old gauges used to be. this dock provides charging through the bike's electrical system and also the interface for the hardware that picks up the rpm and wheel revolutions for speedo.
- are there generic "docks" or the plug bit that plugs into the phone to buy? the rest is simply bracketry that I can machine up.
2) tachometer. this would require the hardware to pick up the electrical pulses at the coil signal wire (not the high voltage coil wire), this is a nominal 12v that goes to 0v then back to 12v. so probably pretty simple in terms of hardware, just a pickup wire, and ground wire, some kind of voltage limiter etc to keep the phone safe and then the iphone plug/dock thing. what kind of signal would the iphone be wanting here? can the iphone handle this type of analog signal or is the interface completely digital?
3) speedo, 2 ways to go here, one is to simply use the GPS information to determine speed. the other and preferred way would be to use either a hall effect sensor on the front wheel or something similar, this signal then gets piped up to the dock. so normally 12v and then a momentary 0v as the sensor passes for 1 wheel rev, then back to 12v.
So, have potentially 2 oscillating signals going to the dock that the app then needs to know how to interpret to then display the corresponding engine RPM and motorcycle speed.
For the tach, the user would need to be able to set how many voltage pulses per sec equals how many rpm, so that you could put in different multipliers for use on different number of cylinder motorcycles.
for the speedo, the user would need to be able to set some kind of multiplier as well, to adjust for front wheel diameter.
in addition, would be nice to add the neutral light indicator, blinker indicator lights into the unit, those are also simply 12v or no volt circuits.
thanks for any help or guidance or links to appropriate materials so I can start this process.
thanks!
dylan
Get thee to Make magazine, my friend!
There are third party cables that let you set up a serial port interface with your iOS device. They cost around $50 if memory serves.
I don't think you could write iOS code to accurately count oscillating pulses into the dock connector on the device. That requires tightly controlled timing code, and/or interrupt level coding, A/D converters, etc.
However, you could build special hardware, and build it into your iPhone/iPod mount that would do what you describe.
There is a microcontroller system called Arduino that is surprisingly easy to use that would make it pretty easy to do what you describe. It can be programmed with a USB interface, and there is an IDE for the Mac that you can use to program it. The programming language is C with some simple extensions. The Arduino has quite a few digital/analog i/o channels, and you should be able to build a simple circuit that moves the input from the RPM line and/or speedo line into a voltage that the Arduino could measure. You could then write code that counts the pulses/second, and send that information up the serial port to your iPhone.
THEN, you'd need to write an app that listened to the serial port for updates from the Arduino and used the incoming messages to display information on the screen. You'd need to design a simple protocol that sent information for new values of each gauge. It could be as simple as a one character tag for RPM or speedo data, and then a 1, 2, or 4 byte integer representing the value for that gauge. (depending on how much precision you wanted. 2 bytes would probably be plenty, since that would give you 65,536 possible settings for your gauge, much more than you could discern with the naked eye.
You'd probably spend $100 - $200 (US) on electronics for a prototype of such a setup. Getting it into a nice package that you could build into a handlebar mounted bracket on the bike would be a lot harder. Then you'd need to etch custom PC boards, build weatherproof housings, etc, etc.
It all seems like a whole lot of work for something you can buy off-the-shelf from an auto parts store. But then, Make magazine is full of such things.
Check out this password generator app that shows various techniques including using a data container singleton object to share data between objects in your project.
thanks for all this, and due to the complex nature of it and the possibility of doing it more through existing apps, I will leave it, at least for now
here is an interesting app i just found, can use sound, or also a pickup through and induction coil over the coil wire, or a simple hookup to the positive of the system, and hooks up through the audio jack!
app and hardware for iphone as motorcycle tach and speedo
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