All posts by Christian

TUG Racing Team

New Updates for X-by-Wire 2012 Software

The last days i was a bit struggeling with the Asynchronous Serial Interface of my last years Board. Today i realized that i have to rework my selfmade console whole from the bottom up but lets start at the beginning of the weekend…

As i mentioned already, the functionality of the new PCB would be the same as in the last year, only downsizing all components to minimum size. Last weekend i took the software and a reserve board from last year, to take a look at the integrated Watchdog of the X-by-Wire Multi Voltage Supply Unit (Infineon TLE6368).

After doing a bit debugging i realized that the printf’s i used for all debug statements were taking incredible long processing time. Time i cannot give for debugging, because a live debug when communicating with all systems in the car would not be possible anymore, because some printf’s take more than 10ms and for the Watchdog of the Supply Unit and the ECU in the Car, some critical Data (Watchdog Reset SPI and Throttle Postition over CAN) has to be provided within 10ms Cycle Time. This is a bit like a hard real time system, because the ECU needs the new data within the 10ms to avoid computing false parameters for the Motor Control Units…

So I decided to do some rework of my Software respectively the Asynchronous Serial Interface for Live Debug Support. Maybe i can post some pictures of the old debug Interface and the cycle times for the used printf’s…

TUG Racing Team

Wire Harness 2012 planning finished

Today we finished checking our Wiring harness.

We have 46 sites of Excel sheets, to look into, for failures in connections between the devices in the electric car.

Because of being scared to oversee some wrong connections i decided to do a connection overview with all connections to make it simpler to inspect the whole wire harness of our car. It should also be easier when building up the wire harness to see what cables end where, and how much cables are going through the two bulk head feed through’s right and left beside the driver to boxes in the rear.

Recent Work, TUG Racing Team

X-by-wire 2012 Layout finished

I’m glad to say that i got the chance to try something completely new for me. 4Layer pcb with 0,1mm lasered blind vias. When downsizing the pcb from last year my focus was on how low can i go with the amount of space.I searched for the smallest parts available, always looking forward in that way, that it has to be possible, to manually assemble the board.

After struggling with the new housing dimensions, i have to say that the X-by-Wire box would have been shrinked to 25% of the last years boxes volume. Due to the using of special connectors and having more than 40 I/O lines the size only shrinked down to 33% of the last years volume. I’m sure its a great step forward for me, because i never had the chance up to now, to use Blindvias for a PCB. Lets hope the boards arrive soon, AT&S is delivering more than 70 boards for the Racing team.

The new Board dimensions are 45x75mm compared to 115x90mm in 2011. This is over 65% PCB space savings! A good job i think…