[Dr_C]

Six Scalextric AMG GT3’s are awaiting fitment of the windscreen LED readouts and a decision to make:

Should I fit the above six display modules which use an FFC 0.5mm pitch flat connector or should I use the latest PCBs to arrive which have the wire hinge for hot-glue mounting on the underside of the vehicle roof?

Photo below shows the PCBs with SMD components and hinge wires fitted:

   

The next photo shows a pair of fully assembled display modules after separation from the ‘framing’ structure.

   

These modules can be controlled by the IR LED signal from a standard SSD decoder to auto-display car ID or alternatively they can be controlled by uart bus, SPI bus or I2C bus (whichever is made available from the in-car decoder).

The ceiling hot-glue approach should provide a neat windscreen install :)

More to follow.

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[Dr_C]

   

Decision made.

The roof PCB component is too long for the AMG roof… so had to be shortened… hence the FFC option is required for electrical connection.

For now, the roof PCB component is attached with double sided tape rather than hot glue - just in case it needs to be removed and refitted during testing.

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[Dr_C]

I’m pleased to report the display firmware for full compatibility with the standard SSD system is now completed.

The displays use a three wire connection onto a standard SSD decoder which itself has standard firmware.

The display automatically shows car ID in the range 1-6. It also illuminates the first decimal point within the display whenever the LC button is pressed.

When the SSD powerbase is used to re-programme the decoder’s ID the display automatically adjusts to the new ID.

The new firmware, internal to the display module, is already designed for compatibility with the 36 ID method, i.e. the ID extension of the SSD method up to 36 cars.

Next, I need to assemble sufficient of these display modules for a grid of 6 SSD AMG GT3s, and then a grid of 18 NSR AMG GT3s. The latter will test compatibility with the ID extension to the SSD method.

Later I will explore firmware updates for Carrera D132 and SCX-Advance compatibility. A slightly different method will be required for oXigen compatibility - I think this is worth doing and would make a nice enhancement of the international 24hr races IMO.

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[Dr_C]

Photo below shows the completed installation of the windscreen 2 digit LED display fitted into a Scalextric AMG GT3. The  car is fitted with a standard SSD rev H decoder complete with JST lighting socket plus the three wire extension harness for powering and controlling the display module.

To assist with vehicle maintenance, the three wire harness can be separated from the display module using the small connection board by unlocking the FFC socket. Meanwhile the ATtiny3226 microcontroller which drives the display can be seen on the rear face of the display module.

   

The next photo shows the car fully assembled and ready to drive away. The car has been programmed to ID 6 using the programming buttons on the ARC PRO powerbase.

   

This final photo shows the resulting display as the LC button is pressed on the SSD wireless throttle controller. As mentioned earlier this illuminates the decimal point.

   

This is a fully drivable SSD car complete with on-board windscreen display :)

As an SSD system windscreen display upgrade this project is now complete.

It’s also complete for application to the 36 car wireless system.

Work on D132, SCX-Advance and oXigen compatibility to follow in due course.

There’s one tiny technical detail which I shall cover below in a further post.

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[Dr_C]

Interestingly, I chose biasing resistors for the LED segments so the display brightness looked about right for readability by the human eye. Using the decoder’s onboard 5V regulator output this required 2.2k Ohm resistors. Sadly my iphone camera didn’t like this level of brightness (too much flare). I had a choice… either to swap out all the bias resistors for something larger or to add some PWM code. I chose the latter. For best results I found I needed to set the duty ratio to 10%. With this setting the display appears readable by eye in daylight and low lighting - and worked for the photos too. This PWM approach also will facilitate correct brightness adjustment when used with decoders which have 3.3V regulators.

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[Drifter2]

Awesome!

[Dr_C]

many thanks drifter2
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[Dr_C]

This project is proving to be a lot of fun. 

I’m finishing the other five scalextric cars using an identical installation. Photos of the six car Scalextric AMG GT3 grid to follow in due course.

Then, when the shorter roof support boards arrive I will complete the twelve car NSR AMG GT3 grid.

The oXigen compatible display version has been designed and should arrive, too, in a couple of weeks. This version will simply display car ID and could be useful to identify cars while pitting.

I’m also going to take a look at full colour miniature displays which may facilitate some other new features ;)

One completed project opens the way for others.

The techy fun continues…

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[Dr_C]

Posting error - post now moved to the correct place. Apologies.

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[Dr_C]

Each of my grid of six Scalextric GT3 cars now has one of the two digit LED windscreen displays fitted and functioning correctly.


As mentioned earlier, the displays have been developed so that a three-wire connection onto a standard SSD in-car decoder auto-updates the display with the car’s current ID.

The following short video shows the car powered by an ARC PRO powerbase. In turn, the powerbase programming buttons are pressed in sequence, programming the decoder ID from 1 through to 6 and then back to 1.

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Video link:

https://youtu.be/M47tIQ6e7LI?feature=shared

ps the slight forward movement is standard with standard SSD in-car decoders when programming the ID.