LED Sequence Driver

The LED Driver is a flexible, self contained microcontroller and output driver module I have developed for providing complex animated lighting for models using LEDs. The exact sequence is determined by custom written code running on the microcontroller and can be tailored to your specific needs, or can be one of several ‘off the shelf’ configurations.

Specification

• 8 independent output lines - Each line is buffered to drive up to 10 LEDs in parallel.
• Variable brightness is available on each output via pulse-width modulation (PWM).
• Up to 4 different sequences can be stored and configured by onboard jumper links.
• Far more sophisticated & flexible than just flashing LEDs
• Supply voltage 4.5V to 12V - On board voltage regulation and reverse polarity protection.
• 3 AA cells will provide several days continuous operation (depending on number of LEDs used).
• 2” x 1.5” PCB Assembled & tested.

The module is supplied programmed with the desired sequence(s). LEDs are not connected or supplied by default since the size, type and colour of LED, value of series resistor and length of wiring will depend on the target model and planned supply voltage, but these can be provided for additional cost. Some basic soldering ability is required to connect the LEDs to the module.

There are 2 basic wiring configurations for the LEDs depending on whether more than one LED per output line is required:

1 LED per output

In this configuration, the series resistor for each LED can be fitted to the module PCB directly which then simplifies wiring. It is only necessary to connect each LED to the appropriate output with 2 wires.

2 or more LEDs per output.

In this configurations, each output is connected to a number of LEDs in parallel, but each LED must also have a resistor in series between the LED and the supply. This complicates the wiring somewhat but can greatly extend the flexibility of the module.

Typical Applications Of The Module.

These are some examples of finished models that incorporate the module, and also some concepts and ideas for possible uses.

UFO lights

This UFO kit has 14 ‘lights’ on the top and bottom of the saucer. I added 2mm LEDs in the top half and 5mm LEDs in the bottom, each half being wired as 2 pairs of 7 opposite each other. Each output drives 4 LEDs, 2 in the top and 2 in the bottom.

Martian War Machine

This features 4 lighting elements – the heat ray, the wing tips, the nose and the underside propulsion ‘legs’. The sequence slowly pulses the heat ray and nose on and off at different rates, slowly increasing in speed over a minute or so whilst the leg lights run a chasing pattern. The Martian then goes into an attack mode where the heat ray and wing tips flash quickly for 10 seconds or so before resetting back to the slow pulse sequence. A total of 19 LEDs are used in this model.

In addition another module was fitted inside the church which has 3 warm white LEDs programmed to individually flicker randomly which provides a very realistic candlelight effect when viewed through the stained glass windows of the church.

Police lightbar

This was a proof of concept to see if a lightbar for a 1/24th Crown Victoria could be built using tiny surface mount LEDs on a custom PCB. The PCB is connected to the module using very thin enamelled wire – this would be easy to hide within the body of the car. The lightbar uses 4 output lines leaving other available for driving additional front & rear lights if necessary.

Aircraft beacons

These are two examples of navigation / anti collision strobes found on aircraft.

Demo units

These examples demonstrate the variety of patterns and sequences that can be implemented.

Lightning and Fire

This module combines a lightning effect and a flickering candle/fire effect as an all in one solution for a haunted house or monster lab type diorama

Price for the basic unit starts at £40 excluding LEDs.

To discuss your requirements further, please drop me a line.