1 March 2018
Another gimmick ... ;-)
It started with a simple requirement. In my daily car I have a metre for the oil temperature. It's amazing sometimes, how much longer the oil needs to get to a proper operating temperature compared to the cooling liquid.
So I wanted to include the oil temperature measurement into this car. But - as you've seen in the cluster section - there's just no space in the cluster. So I came up with the idea to integrate a display into the ashtray (I'm not smoking).
So while I'm at it, an outside temperature would be handy as well. So I started fiddling and the same electronic circuit with the microprocessor drives that display.
I sourced an outside temp sensor from an old C-Class (W203) and an oil temp sensor directly from VDO. My math knowledge from school had to be dug out to find the formula for resistance vs. temperature in both sensors (logarithmic curve).
I designed a display holder in 3D, printed it out and it fit the display straight away. The display itself has 320x240 pixels, even touchscreen (not used at the moment). It took me a while to be able to show the Pick-Up-Bitmap on the display, but now it works.
That display cost an amazing amout of 9 Euros, the hours I'm not counting ;-)
Ashtray Display (II)
2 April 2019
You have no idea ...
… how much work is involved in such a gimmick. Worked another day on it; it has to fit the ashtray, the connector needs space, it has to fit the centre console, should open and close and and and …
Also the locking mechanism, i. e. that the thing doesn't fall out, when you open it, proved to be a challenge. The standard metal strip doesn't work as it is in the middle of the display. So I constructed a spring mechanism for the right side … didn't work either; too assymetric, so the ashtray isn't straight when you pull it out.
Finally I attached a spring mechanism from an old cassette player at the back of the ashtray, which can be pulled down, when the ashtray should be taken out.
Anyway, the whole ashtray will be sprayed black, the display holder has ist final design (at least 10-15 test prints) and we'll get there ...
Ashtray Display (III) ... Finished
13 April 2019