External ambient temperature.

[MAXTHEDOG]

Hi All ,
One thing I think I’ll miss come the winter is an external outside air temperature reading or indicator.
Being someone with definite geek tendencies rather than go and buy an off the shelf widget, which would be boring I rigged this up:

Using the Arduino processor board and three LED’s to indicate cold(green), normal(yellow), and hot(red) with changeover temperatures of 20 and 25 Celsius; green below 20, yellow between 20 and 25, and red above 25.
The final incarnation will be just one RGB LED mounted somewhere that it’ll give a coloured glow of probably one of 6 colours - deep blue for anything below 5 C, maybe light blue for 5 to 10C, light green for 10 to 15, green for 15 to 20, orange for 20 to 25, and red for 25 and above. Just waiting on delivery of the RGB LED’s.
I suppose I could add a buzzer or some audio warning below 5 C although I think commercial manufacturers use 3/4 C.
Anyways now I’ve admitted to having too much time on my hands, I’ll bid to a good day.
Regards,
Michael
Cold

Hot

In between

[Notanumber]

That's a handy bit of circuitry I'd like to try to replicate. It would be my first experience of building with an Arduino; what will i need to buy please ?

[MAXTHEDOG]

Hi,
The first thing I’d do is watch as many You Tube videos as you can bear on the simple things. Really basic like getting an LED to blink is usually the first thing to do. You’ll also need a computer with bog standard USB, nothing fancy, I’ve used a MacBook from 2009 and it runs without breaking into a sweat.
There are plenty of starter kits to be had on Amazon/EBay etc, but I wouldn’t spend any money until you’ve watched a few YT videos to get an idea of the programming needed. I come from a Controls background where programming ( in a different language)was a daily thing and I still struggle with the finer points of Arduino. It’s not difficult as such, practice as ever makes perfect. The board in the photos is OTT for what I’m doing but once it’s up and running I’ll get the more suitable board that’s 45mm by 18mm. It’s just as capable as the one in the photo it’s just smaller. If you Google Arduino you’ll find their website with loads of examples of what can be done. They also have a forum to post for help etc just like this. Be warned though it can be an addictive rabbit hole as these things can run displays - colour and mono, LCD, LED,TFT,OLED, log data, drive motors, surf the web, switch your lights and heating on/off……Monitor your engine bay temperature and fans. I did a fan control system for hi-Fi amplifiers with a 4 line by 20 character LCD display with 4 pages, two sensors and push buttons for up/down page navigation and a temperature setting control. It took quite a few hours, but the amount of learning you get is immense. Just like tackling a job on our cars. Any other questions just ask, you’ll soon be up and running and adding auto lights and wipers…..
Regards,
Michael.

[Rob Bell]

The MGF had an official accessory to read outside temperature, that used lamps to tell you if it was freezing outside. It fitted into one of the centre console switch blanking panels.

I don't think I have seen one in the wild though - only in an accessories catalogue (I can't find the picture currently) - I guess in the 1990s, folks did not feel the need to know ambient temperature, but it is ubiquitous these days in new cars.

I like this idea Michael - how are you planning to integrate it into the dash?

I think the arduino would make a cost effective rpm/ gearchange indicator!

[MAXTHEDOG]

Hi All,
Apologies for the delay in responding. Been away in France attending to elderly in laws health issues……
Rob - I’ve got one spare blank in the switches that I could use but I’m mindful of the brightness of an LED ‘staring’ at me in the dark when it’s cold. I might end up locating it somewhere where it isn’t aimed directly but gives a ‘glow’ sufficient to do the indicating job. I still haven’t decided whether I’d have and RGB to light up blue for ice warning, green for normal and red for above temperature X or just a single LED to indicate possibility of ice. Both seem overkill of the Arduinos capabilities so I’m thinking of other things to at the same time.
You’re correct that this and other things are in almost every vehicle now, probably as a result of the design team thinking well we’ve paid for a processor with X inputs and outputs and only used a third of them, what else can we use it for!
Regards,
Michael.

[colintf]

The MGF had an official accessory to read outside temperature, that used lamps to tell you if it was freezing outside. It fitted into one of the centre console switch blanking panels.

I don't think I have seen one in the wild though - only in an accessories catalogue (I can't find the picture currently) - I guess in the 1990s, folks did not feel the need to know ambient temperature, but it is ubiquitous these days in new cars.

I like this idea Michael - how are you planning to integrate it into the dash?

I think the arduino would make a cost effective rpm/ gearchange indicator!

i've had one in my TF from new Rob

[Rob Bell]

Nice! Have you got any pictures to share? It was just a pair of rectangular LED in a circular plastic fitting, that was attached to a switch blank from memory...

[colintf]

Nice! Have you got any pictures to share? It was just a pair of rectangular LED in a circular plastic fitting, that was attached to a switch blank from memory...

none at the moment - i must remember to take some at the weekend.

its in one of the switch locations in between the electric window switches, but pretty much as you described.
from memory it was ordered at new, but dealer fitted not factory fitted.

[Chris Tideswell]

For reference I believe that the OEM part number for the loom is VUB100230

[Rob Bell]

Yes, I think this was a dealer-fit option only.

[mowog73]

Interestingly, here in Canada, I have seen 3 MGFs installed with this MGF accessory, all cars were German-export cars.

[Rob Bell]

Probably makes more sense in the German market, where snow is much more likely than here in the UK... Of course, practically all new cars have this feature as standard...