Sat Nav splash screen

Need to be in the right mood to fiddle with cars - today was more a futer (as my wife would say) with images day - to produce a splash screen for the satnav

Route is settled, ferry booked as are overnight stops save one.

Because - tinkering

Part way through a little project - adding multiple headphone outputs and mic inputs to the existing FM Radio/SD card player system.

Motorcycle or Rally intercoms can all be bought off the shelf, for a price. 

I'm more interested in tinkering and dismantling/hacking/integrating a few existing components to see what I can come up with. Wireless is overrated IMO - just more things to charge up!

The Schematic

The principle is to leave the audio route from main Head Unit to speakers and rear headphone jack alone since that works well.

Dotted line is the new unit, double arrows stereo paths, single arrows mono paths.

Green boxes are off the shelf components hacked slightly and integrated, Red - switches, Yellow - built up components etc. Two Microphones will switch in via a relay which also mutes the head unit via push to talk switches. The Amplirider will mix in the Mic signal and can be powered by head unit or intercom box depending which is turned on.

The build

Must clean up the bench!
Mic Amps mocked up and tested, currently working out the layout for the case

Layout should work:
    Output stage is a modified Behringer HA400 Headphone amplifier,
    Input Mic Pre-amp boards from an unbranded Ebay source
    Buck/Boost Power supply to provide stable 12v, again Ebay

Biggest expected challenge to be potential ground loop issues and wind noise in the Microphones - can't be any worse than the current drive/passenger 'shouting at each other' mode of communication.

More detail to follow.

Update - This approach was not completed, I invested in a motorcycle intercom and went wireless instead!

Broke the 2016 Duck

Broke the duck and despite the cold, but dry, weather took the Zero out for the first spin of the year.

South through Kent & East Sussex: Towards Hastings, Rye, Romney Marsh, good Pub lunch at the Woolpack Inn  in front of an open fire then a convoluted route home. No sat nav, so mostly just heading sort of south until sea blocked my path then east and choosing any road which looked interesting.

A little bit of pure escapism...
Open road the chance to concentrate on the drive and when in traffic to look at the Kent/Sussex countryside view.

Gave me a chance to test out a Christmas present - some earmuff come headphones.

A pair of Howard Leight Syncs do the job nicely - passive noise protection which massively reduced wind noise and buffeting, a decent sound driven through the Amplirider and not least keeps my ears warm!

Picked up some engine oil on the way back ready for the Annual oil change (When I'm in the mood to crawl around under the car)

Map Switch

The car ran on an alternate map for IVA and with the first MOT approaching in the summer I got around to building an ECU map selection switch. This is meant for temporary installation - plugging into the Aux input socket on the ECU.

Design

The circuit designed to switch between the 3 possible Maps supported by the Emerald ECU. The second pole of the switch set to illuminate a LED confirmation of position.

The LED is setup to always illuminate Green, then also illuminate Blue or Red depending on the map selected - in theory this gives Orange and Turquoise. I installed a POT to allow dimming of the green to adjust the colour mix, in the end the POT probably wasn't necessary - the Blue and Red components are so strong they drown out the green anyway.

Wiring

ECU line #7b is configured as Map switch input - either open, grounded or grounded via a 1k Ohm resistor

ECU line #1 is the ground input

ECU line #8 & 9 are used to power the very low current LED draw

#8 & #9 are input pins with internal 1k pullups to 5v. I checked with Karl at Emerald and he suggested tying both together and using as outputs - it works, there is just enough current to drive the LED which only needs about 7-8ma when two colours are lit.

Assembly

Assembled in a small project box, possibly too small...

Connected via IDC cable to a right angled 9 pin D-Sub plug so it doesn't encroach into the passenger footwell.

Testing

 ...and in one possible location, just testing the configuration for now

Switch position 'O' gives green and selects Map 3, same as unplugging the unit:

Position 'I' gives blue and selects Map 1:

Position 'II' gives red and selects Map 2:

Next step is fiddling with the ECU setup itself to read the map selector from input #7b and copy in my 3 intended maps.

Half thinking about putting a VW logo on it ;)...

Update - This little box doesn't get used, I replaced the map switch with a more permanent install here and here