the goal is to make a remote start system for my car
to that end, i'll simply place a remote keyfob in the trunk and set up a servo to poke the remote start button on said remote whenever i send it a certain text message. Later on i'll build something in app inventor as a front end for the text message sending.
basically i'm asking;
-has anyone done this before? and possibly left some documentation? specifically libraries used and maybe some code snippets
-in what ways might the gsm and motor shields not be compatible? maybe they use similar pins so it wont work? or they used different voltages? is there a workaround?
-do i even NEED the motor shield? i'd just be driving two servos at max...
Since you're posting in Project Guidance, let me start by asking whether what you propose is safe and legal, and whether your insurers would cover it. Here in the UK it would not be legal, and I would expect insurers to decline to cover a vehicle when it was used.
You should also consider whether it's desirable. If you're envisaging this as a way to warm the car up for you on a cold winter's day, you ought to know that leaving the car idling is not a good way to warm it up - it is very bad for the engine. A block heater is a far better way.
PeterH:
Since you're posting in Project Guidance, let me start by asking whether what you propose is safe and legal, and whether your insurers would cover it. Here in the UK it would not be legal, and I would expect insurers to decline to cover a vehicle when it was used.
You should also consider whether it's desirable. If you're envisaging this as a way to warm the car up for you on a cold winter's day, you ought to know that leaving the car idling is not a good way to warm it up - it is very bad for the engine. A block heater is a far better way.
legal yes, many new cars do this. and many older cars are wired for this capability using aftermarket systems like Viper. Insurance doesnt really factor into it as far as i know, as Viper and Computstar dont mention anything about insurance differences.
as for cold starts, i'd be starting the engine cold anyway, the only difference is when i get into it
as for cold idling, it doesnt stay cold for long at all.
and as for damage, that's what engine maintenance is for. lots of people refuse to wrench their own cars and it's a little aggravating.
i'll simply place a remote keyfob in the trunk and set up a servo to poke the remote start button on said remote whenever i send it a certain text message
I really hope it's not that simple - what about safety interlocks?
joekitch:
as for cold idling, it doesnt stay cold for long at all.
and as for damage, that's what engine maintenance is for. lots of people refuse to wrench their own cars and it's a little aggravating.
I disagree. Leaving an engine to warm up at idle is extremely bad for it, and especially so in cold conditions where you'd be most likely to use this feature. Cold running is one of the most damaging situations for an engine and so you want the engine to warm up quickly. Leaving it at idle without any load on results in the longest possible warm up which means the maximum possible damage.
I don't know why you are aggravated by people who choose not to service their cars themselves, but servicing does not prevent the damage you're causing by leaving the engine at cold idle.
Whether it's legal would presumably depend where you are - as I said, it would be explicitly illegal here in the UK. The same would apply to insurance. If you are somewhere where these devices are common, perhaps insurers would be used to them and accept the extra risks. Here, I would expect insurers to be highly interested in modifications which made it possible to start a car without being in possession of the key, and without having a person responsible for determining that it was safe to start it.
i'll simply place a remote keyfob in the trunk and set up a servo to poke the remote start button on said remote whenever i send it a certain text message
I really hope it's not that simple - what about safety interlocks?
not entirely sure what you mean. having a remote starter in a car doesn't suddenly make it easy to steal. pretty much every aftermarket remote start system is probably more secure than your stock car. basically if you touch anything and the designated keyfob isnt within proximity range (inside the car) the system shuts itself off
if you mean the keyless access system being "too close" and letting the doors unlock if you have a keyfob in the trunk, i'm developing ways around that, possibly by disconnecting the proximity coils on the keyfob (not the radio coils) or placing the key start assembly in a metallic container. it'll reduce the keyfob's proximity range to zero, and the radio range to only a few feet....but the radio range only needs to go a few feet anyway.
and as for security, there are plenty of ways to stash small packages in a car to where you'll never find them unless you know exactly were it is.
zoomkat:
Your project has several big parts. Decide which is the most difficult and work that part out first, then move to the easier parts.
wait, so
-send text message to gsm shield
-gsm shield makes a servo move 90 degrees
is a big project?
i dont know much about it yet but i didnt think it was...big...