It’s not just wiring! Tech Engineering, the company behind WireTrain, also get involved in many weird and wonderful projects…this one was taking us on a trip back to the 70’s.
The controls of the 70’s
In the mid 1970 Aston Martin produced the Lagonda. It was a technical marvel of its time, with touch button controls, electrically operated functions everywhere and a fully digital dash. Sadly, its reputation became associated with woefully unreliable electronics rather than being a titan of 80’s tech. The series 1 digital dashes in particular were known for being problematic, with more fantastical versions in the series II and III hoping to improve the reliability.
The project brief
We were approached to build a faithful reproduction of the original series 1 digital dash, but using modern componentry, this would then communicate using CAN with the new chassis harness and now under the faultless control of 3 LIFE Racing PDUs. Just getting the dimensions of the digital dash’s PCB into CAD was a drama, in the 70’s everything was laid out by hand so there are odd tweaks where items are a few critical millimetres out of square and alignment, this was faithfully reproduced into a sizable 19″x6″ (~480x155mm) PCB.
Quite the technical challenge
A robust automotive grade 18F PIC microcontroller uses i2C to talk to 6 seven-segment driver chips and separate digital input, output and analogue daughter boards. The design choice to have separate daughter boards for the I/O made both production and development on a budget easier, since when an interface issue was could just re-spin the interface board and not the whole monster PCB. This project was quite a technical challenge for our small team, not least the custom PIC firmware juggling all of the display updates, I/O and Car communications.
We loved the challenge but were impressed by the customer’s faith given that the first proper shake-down of this totally rewired car was a road trip from the UK to Italy and back!