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By the way, I told a friend about this today and he said this solution is pretty common in VW cars, there's even a built-in kit in Aliexpress which I think uses the same light sensor as you do. Wonder what hardware will be inside that one. I think it also shares the connector with our cars, but not sure how it would work since those VW don't have the "Home" function: https://aliexpress.com/item/1005006123319012.html
By the way, I told a friend about this today and he said this solution is pretty common in VW cars, there's even a built-in kit in Aliexpress which I think uses the same light sensor as you do. Wonder what hardware will be inside that one. I think it also shares the connector with our cars, but not sure how it would work since those VW don't have the "Home" function: https://aliexpress.com/item/1005006123319012.html
Yes, that was pretty much my inspiration.
The problem is that even though the light switch and the connectors are mechanical identical (to the 997.1 NOT the 997.2), electrically they are NOT:
Porsche uses "active ground" and VW uses "active 12V". The Porsche solution is more elegant by the way.
If you would plug in the AliExpress adapter into your Porsche you would smell burning cable/electronics.
Last edited by Hatzenbach; 01-16-2024 at 12:28 PM.
the "light sensor" in the center of the dashboard is actually an INFRARED light sensor and - unfortunately - it doesn't look like it can reliably be used for my solution
it's main purpose seems to be to determine when the sun is really burning down and then it cranks up the fan of the A/C. If you have an infrared light, shine it on the sensor for 5 seconds (with ignition on) and then watch the fan come to life
I am no longer using the old supplier for the light sensor, which also means I am now using original 3M VHB tape, so the (non) stickiness issues should be a thing of the past
and last not least, as requested by some, I am now also accepting PayPal on my eCommerce site www.997research.com
Bummer about the stock sensor, but I guess it's not like running the new sensor is very hard. I wonder what that IR sensor actually does if you have manual HVAC? It shows as hooked up to the manual system but everything is...manual...so I'm not sure what it would change.
Random thoughts on a Saturday morning: I'm curious about the control of the lights. I assume there's a set point coded into the little computer, is that programmable via the USB port? Like, if you wanted it to be more/less sensitive could that be done via a firmware update? That might be neat, though it seems to be working well for me as-is.
I assume no way to get the lights to automatically turn on when the wipers are on? That would probably require canbus data as I doubt the two systems are otherwise linked.
I have spent the morning reading the several threads on auto lights for the 9X7 gen cars. From v1 to funnelofdoom timer to this impressive v2.
I have been waiting for a clean integration of the light sensors already in the car. Looks like at least 3 exist? Dash top(ir), in gauge cluster, and the rear view mirror.
@Hatzenbach Do you plan to continue investigating other sources for the sensor? Otherwise I’m ready to order the v2 module. The addition of oem connectors really elevated the module. Glad to see those were not printed as other suggested.
Might be of interest;
I did purchase and try one of the cheap VW auto sensing switches. Went through the full range of positions without any magic smoke, but it did not work of course. Switch LEDs turned on and actually I think a couple of the exterior lights turned on as well.
The interesting part about this switch is the integration of the light sensor in the actual ****. Your kit uses the much superior quality original switch so this isn’t of much value, but I suppose a replacement **** could be made with an integrated sensor.
Amazon link https://a.co/d/gbLrzu5
@Spin7 to your question: At the moment I'm not pursuing the "hunt for other built in light sensors". I rather want to use my time to turn the SportChrono replacement into a product. I added a few jumpers that allow the users to select which modes they want to see (and not)
About the VW switch: Interesting concept of integrating the light sensor into the light switch. I wonder how accurate that can be.
By the way: you were luckier than me. I once accidentally plugged a VW switch in and the that was the end of the switch. No big loss though ;-)
the "light sensor" in the center of the dashboard is actually an INFRARED light sensor and - unfortunately - it doesn't look like it can reliably be used for my solution
it's main purpose seems to be to determine when the sun is really burning down and then it cranks up the fan of the A/C. If you have an infrared light, shine it on the sensor for 5 seconds (with ignition on) and then watch the fan come to life
Stand-alone, this is a good step forward to understanding how everything works...
I am happy with the stand-alone sensor with your box regardless.
For what it's worth a couple more thoughts about using the existing built-in Porsche light sensors:
In order to work "as designed" the light sensor needs to be exposed to the sky and should not be "confused" by interior lights and oncoming headlights from other cars. I guess the reason is obvious.
This immediately takes out the sensor in the rear view mirror (which "looks" straight into the headlights of oncoming cars) and the sensor in the gauge cluster (which measures only the cabin brightness).
So that leaves us with only the IR sensor on the dash, and I explained earlier what that doesn't work for my application.
But there's another reason: My goal always was to make the whole solution plug & play. And with the OEM Porsche (well actually they are from Audi ;-) connectors I think it's as plug & play as possible.
Tapping into the IR sensor would have been fairly easy, I already found the OEM connectors for that and installing it would still have been plug & play.
However, tapping into either the rear view mirror or the gauge cluster is a whole different ball game. This is finicky stuff and I wouldn't expect from anyone to - for example - take the gauge cluster off and slice into the wiring harness behind the gauge cluster
The only other option would be to get the light measurements directly from the CAN bus, but that would be total overkill.
Summary: I think it's "as good as it gets" with the external lightsensor
Summary: I think it's "as good as it gets" with the external light sensor
Thanks again for the detailed investigation and description.
Though another thing on my dash, your ambient light sensor is less obtrusive than the GPS antenna, infrared sensor, and SC clock...
Hi, reveived mine today in France, can't wait to try it out, will report when installed.
It's a 2.1, do you know what type of sticky 3M it use and if I should replace it prior installation ?
Hi Nicolas,
Good to hear, your has already the "upgraded" 3M VHB tape, so there should be no need to change the tape
But it's probably a good idea to clean the area where you will put it
01-15-2024, 07:55 PM
