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Adding foot trigger for rear hatch on HiHy

Discussion in 'Toyota Hybrids and EVs' started by BrettS, Dec 4, 2012.

  1. BrettS

    BrettS Active Member

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    OK, have you guys seen the new Ford Escape with it's foot activated rear hatch? If not, take a look at this...


    It seems incredibly convenient and I know I'd use that feature pretty often, so I'm thinking of trying to make something to allow me to trigger the rear hatch on my HiHy with my foot. The HiHy already has a power hatch and SKS, which seem to be the difficult bits. All I would need to do is come up with some sort of foot detector to unlock the hatch and trigger the opener.

    I'm posting this on the off chance that someone else has been working on something similar or to see if there's any other interest in something like this. If so, I'll let you guys know how it goes.
     
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  2. Trollbait

    Trollbait It's a D&D thing

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    Somewhere among the C-max threads, it was mentioned that getting that hatch to work reliably was a bit tricky. You don't want blown trash triggering it or it opening while driving.

    A physical foot switch would be easier to install and get working. The Highlander's height might make finding a spot for it that wouldn't be too high an issue.
     
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  3. BrettS

    BrettS Active Member

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    I had considered that and I planned to tie into an existing trigger to open the hatch... probably the button on the dash. I'm assuming that already has safeguards in place to avoid opening the hatch when the car is in motion or when the doors are locked, which should prevent most accidental openings... although I guess I should test that theory.

    Yeah, I'm thinking a physical switch may be the way to go. It's not quite as cool, but it does have a number of advantages... no false triggers, no worry about power draw (I don't want to install something that'll drain the battery if I don't drive the car for a few days) and it should be cheaper too.
     
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  4. Trollbait

    Trollbait It's a D&D thing

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    Can the power hatch already be open from the outside? If the only way to activate the auto opening is from the inside, then you might have problems in having to defeat some of the safety protocols.

    I'm guessing the fob has a button to do it. Perhaps you can get a non-sks fob with the same code to open the gate. Wire it to a foot switch and power, and ta da, you have your switch. The tricky part is keeping anybody from opening the door. Wiring the power in with the sks sensor so that power isn't supplied without the sks fob is present might be the way to go. You'll need to info on the sks workings and wirings, which I don't have.
     
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  5. BrettS

    BrettS Active Member

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    The fob does have a hatch release button, but I don't like using the fob for a number of reasons... first it's expensive... I do not know if I can get a non-sks fob or not, but either way it's probably going to be several hundred dollars to get the fob and have it programmed. I'm hoping to keep this well under that price. It also gets to be a bit tricky trying to disable it expect for when my SKS fob is near by.

    I spent a little time playing around with the car last night and there is a button on the dash to open the hatch. It does work while the car is off as long as the doors are unlocked.

    So I think I'd wind up making a two step trigger. When I hit the foot button it would first attempt to unlock the doors via SKS... I'm hoping I can just connect to the hatch release button on the hatch for this. Once the doors are unlocked I would tie it into the hatch open button on the dash to actually open the hatch. Unfortunately my wife drives the highlander most of the time, so I don't have a lot of time to play with it, but maybe later this week or over the weekend I'll have a few minutes to try to do a POC
     
  6. BrettS

    BrettS Active Member

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    Well, in case anyone is following this or cares, I played around with this a little and it looks like it's really going to be pretty easy to implement. As I said above, the hatch open button on the dash won't work unless the doors are unlocked. (Additionally it will only work when the car is in park, so there's no danger of accidentally opening the hatch while you're driving down the highway). So, the hatch can easily be opened by first pressing the hatch release button on the outside of the hatch. If the keyfob is near that will unlock the doors. Then if you press the hatch open button on the dash the hatch will actually open.

    If someone (or something) triggers it without a keyfob near by then the doors won't unlock, so the hatch won't open. If something triggers it while you're driving the car won't allow the hatch to open since it's not in park.

    So now I have the following tasks:

    - Figure out which wire to tie into to trigger the hatch release button on the hatch itself. I may have to pick up a two day TIS subscription if I can't easily identify it otherwise.

    - Figure out where to run my wires through the car.

    - Come up with a simple circuit to trigger the two buttons in sequence. Additionally the hatch open button on the dash needs to be held down for a second or two before it triggers.

    - Figure out what I'm going to use to trigger the system... a button would be cheap and easy, but less cool than a motion detector. One of my friends suggested using an IR Beam, which might be reasonably inexpensive and less sensitive to false triggers, but I'm worried about trying to find a way to mount the IR LED and receiver where they won't be knocked off by a carwash or if I drive over a branch or something. I may start out with a button and then try to come up with something better if that gets to be annoying.
     
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  7. bisco

    bisco cookie crumbler

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    i'm watching brett, i admired the work you did implementing sks. all the best!
     
  8. BrettS

    BrettS Active Member

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    I had some time on Saturday, so I spent a few hours working on this and made some progress. I connected a wire to the button on the hatch that will unlock the doors, and connected another wire to the hatch open button on the dash and ran both of these wires to the same place in the back of the car. I also ran a couple of wires from that same spot outside underneath the car to the place where whatever I use to trigger this will go. So now all I need is a button or motion detector or something to trigger it and the circuit to fire everything in the right order.

    Now that I had access to the wires for the unlock and open buttons in the same place I played around with it a bit. I was kind of hoping that if I connected both wires to ground at the same time and held it long enough for the open button to trigger that it would unlock the doors and open the hatch, but unfortunately that is not the case. There definitely needs to be a short delay between the time the unlock signal is sent and the time the open hatch signal is sent. So this will make it a little more complicated than I was hoping, but I've been kicking around a few ideas and I think I'll have some time to play with it today and we'll see if we can come up with something that works.

    Assuming that goes well I'll just need something to trigger the whole thing. I'm kind of leaning toward a button to start with since that will be cheap and quick and easy. Then depending on how much of a pain it is to kick the button I might consider switching to a motion detector of some sort instead. The only problem is I really haven't come up with any good options for a large waterproof momentary button. If any of you guys has any thoughts on where to find a button for this I'd love to hear them.

    Alternately, if I can't find a good source for a button then maybe I go right to a motion detector, so if you have any thoughts about a decent waterproof motion detector I'd love to hear that as well.

    Thanks,
    Brett