Hi all,

Starting (well - already started) a new project,
since there is no coolant temperature indication somewhere, I'm going to install a display in the dash center vent, sacrificing the left outlet.
Principle is as follows: Arduino Nano retrieves data from a OBD2 Bluetooth dongle by means of a HC-05 Bluetooth module, and sends data to the display.
The display screen is "transflective", which means it is still visible in bright sunlight.

3 extra parts will be incorporated:
- a button to change display information,
- a photo resistor in order to automatically change the screen brightness
- a switch to turn off the device so you can pair to the OBD2 dongle with my phone

Probable an additional switch and USB port will be added so firmware can be updated.

The dash center vent part will be 3D printed (SLS nylon), primed, sanded and SEM texture painted.

a provisional pdf (clickable) scheme can be seen: google drive link

If others are interested in this, I'll explain needed things more in depth.

Some pictures:

a "timeline" design stage picture of the center vent part 3D print,
left is the start right is where I am now at.




zoomed in a little, with annotations




Backside of the center vent part 3D print, with the arduino nano, HC-05 bluetooth module and the display module




Of course right-hand drivers may like this, so a mirrored 3D print design will be available (or if you want your passenger looking at it).
At the most right, a design for more switches, replacing the round "air direction dial" (will contain the extra switch and USB breakout socket).




Some schematics (the same as the previous mentioned clickable pdf)




a first quick print on my 3D printer with PLA, just to test if it fits right.
There's some work to do, on the left side and right top it doesn't fit well. and the screen I will move a little to the front.
Remember, the final design will be 3rd party printed with SLS nylon, which results in a much better quality and will be weather-proof.
See this picture, where I have a 7" display bezel printed with SLS nylon and painted (the middle part), for my former car.




a youtube video is made when testing the display for the 1st time.
A light intensity-value between 0 and 1023 is displayed.
Watch the video on youtube, there is more info in the description.

 

That's a kind of cool way to do that. Any way to have the display flanked by vent holes anyway? There seems to be a lot of room to have air around the display panel.
I'd not want to give up a vent, I like air blowing on me.

 

Forgot to mention,
I got me a spare center dash vent part off ebay

EDIT:
of course, air flow needs to be blocked from behind ....

 

Didn't think of that yet, could be possible if I move the switches e.a. somewhere else.
On the other hand, I would not like to heat up the electronics behind the bezel.

 

What if the circuit board was also somewhere else so only the display would be there? Perhaps an aluminum heat shield behind it too.

 

Updated the scheme, turns out an Arduino can only be powered with 5V connected to the 5V pin, not by the Vin pin ...
By the way ... maybe I switch to designing a display for in the ashtray location.

scheme pdf: google drive link

 

Something in the ashtray area would peak my interest, I have no desire to replace my air vents at the top of the dash... Great work, so far...

 

Agreed. Nice work, but the look/ location are not for me. Digging the skill though!

 

That is a sweet setup. Very nice. You could probably sell these skills to car guys who want some custom electronic readouts.

 

Ok so I decided to change it to the ashtray location. Ashtray is totally redesigned in 3D, and already offered to a 3D company through www.treatstock.co.uk having it printed with black SLS nylon.
Below some pics of the design. all 4 parts will snap in. The biggest challenge will be writing some suitable arduino code.
p.s. last Thursday I picked up my car from having the LPG equipment installed, later more about that in my other thread (I have to take the pictures when it stops raining)
p.s.2 how do I change the the thread title to "OBD2 display in ashtray location" ?

Pictures:



Electrical scheme (pdf) again changed, 1 switch is not needed any more.

 

You can't, I can ............ DONE.

Graham

 

I notice you are in the Netherlands Cabrio, hopefully it's stopped raining now, so two questions

1) Do you have an idea as to cost of this ashtray model?
2) Where's your LPG write-up/pics, hopefully you didn't have to drill the gorgeous bodywork?

 

Hello Marky,
The LPG thread is at the bottom of:
https://www.jaguarforums.com/forum/x...rtible-232026/
For your 2014 XK there is no LPG installation available unfortunately (yet) due to the direct injection...
but there is a company in the UK that has converted a 4.2 XKR:
http://www.go-lpg.co.uk/XKRV8_S2.html

Ashtray costs ex shipping costs (assuming you're getting stuff from Aliexpress):
- Arduino Nano (clone) ￡ 2.50
- HC-05 bluetooth ￡ 3.00
- slide switch (10x) ￡ 0.50
- power converter ￡1.00
- Transflective Display ￡2.50
- momentary button (10x) ￡1.50
- photo resistor (20x) ￡0.75
- resistor set ￡3.00
The ashtray 3D print (SLS nylon) I ordered for $38.54 (converted ￡30.41) at www.3dprint-lab.nl through www.treatstock.com. if you use a local print shop, the price could be different.
That's a total of ￡45.16. Maybe you need an OBD2 bluetooth scanner, some wiring, an "add-a-fuse", some paint to finish the ashtray 3D print, etc.
The previously mentioned PDF contains links to my purchased items.

 

Forgot to mention, you also need some soldering skills.
The power I get from the cigar lighter (which is already gone - replaced by the LPG switch button)
When the 3D print is delivered, I'm going check if it fits, and upload the STL's to share.

 

Thanks for sharing the details. I appreciate your tenacious work in developing this idea. I too like the new location. I have a Android OBD transmitter and have been using my old Android cell. I guess I can share the CIGAR lighter port with my charging cable for the cell? Looking forward to seeing your project complete.
Shall I start ordering the parts available now and await the finished case?

 

Hope this helps...I created a Pic list, thanks to "Cabrio Bob". It doesn't include the case.

 

RedRider,
Ordering part sure you can do.
Some comments:
The HC-05 has to be paired (look for AT commands) to the bluetooth OBD2 dongle once, and I read some stories on the net that this is not successful.
I may change my design using an "Bluno Nano" (preferably header-less), and I'm not sure if this will pair to the OBD2 dongle. If this works, it will make the HC-05 obsolete.
There is also a Nano 33 BLE, but runs of 3.3V in stead of 5V. One other variant is the Nano V3.0 with NRF24l01 Bluetooth 4.0 NANO-V3.0 which seems to be 5V.
The "add a fuse" is only needed if you draw power from a fuse box. I'm grabbing power from underneath the cigar lighter.
I may change the ashtray 3D design by using the 2 plastic pins on the bottom as power inlet, exchanging the plastic pins with metal, and making them connect when the ashtray slides in.
Writing the Arduino code, I'm going to use the SSD1283A library. unfortunately this is not equipped yet with custom font, which I will try to embed.

 

Sadly my soldering skills aren't too great, so regrettably will give it a miss.

If however anyone were to make these with a 100%+ mark-up plus shipping, then I'd be happy to pay in advance (pre production) via PayPal

Gotta admire your attention to detail Bob, and thank you for your pioneering work, as I think t takes an XK owner to appreciate what others would want in their cars.

 

Ok Mate, I'll "hang loose" until you get this sorted to perfection. I like the idea of the "sliding" ashtray possibility. I just added the fuse relay as a potential component, the idea was to align pic reference with your list. As I mentioned, I already have an Android OBD reader, actually a couple, as I was seeking to use my IOS device in place of my old Android cell for the readout.
BTW, what gauge wiring id used?