Emergency LED strobe, AVR controlled

33 high intensity LEDs are controlled with a AVR ATtiny2313 microcontroller. Four flashing patterns that can be set manually or cycle through. Uses an AVR ATtiny2313 microcontroller.

Details

The emergency strobe light consists of 33 high intensive 5 mm LEDs and control circuit. It has four sequences, and can be set on a single sequence or to cycle through every fifth second. When selecting a sequence manually it is stored in EEPROM and continues on power-up. If an external controlling unit is plugged in; the internal sequences will stop and the external unit is in control. This makes it possible to synchronize multiple units. LEDs are driven by a PWM output, module is powered by 9-24V.

Video

Sequences

1. Flashing with fade
2. 3 x strobe, pause
3. Random pause strobe
4. Strobe

I/O

Inputs

1. PD.0 : Automatic mode change
2. PD.1 : Manual mode change
3. PD.2 : External controller: available
4. PD.3 : External controller: pulse constant
5. PD.4 : External controller: pulse fade

Outputs

1. PB.0 : Mode 1
2. PB.1 : Mode 2
3. PB.3 : LEDs (PWM)
4. PB.5 : Mode 3
5. PB.6 : Mode 4
6. PB.7 : External Mode

D-Sub 9-pin

1. 12/13.8 V +
2. 5 V +
3. GND
4. Trigger on/off
5. Trigger fade on/off
6. Trigger common +
7. External controller available (N.O)
8. External controller available (N.O)

Photos

Source code

Schematic drawing

Parts list

• 1 × AVR ATtiny2313-20PU, DIL-20, 20 MHz, 18 I/Os
• 1 × Capacitor, aluminium electrolytic, 10 µF, 25V
• 2 × Capacitor, aluminium electrolytic, 47 µF, 25V
• 1 × Capacitor, ceramic, 1 nF, 100V
• 1 × D-sub soldering cups, 9 pin male
• 1 × DIL socket, 20-pin, 7.62mm
• 2 × DIL socket, 6-pin, 7.62mm
• 1 × Enclosure, plastic (1591), 120x80x59mm
• 1 × Fuse 5x20 mm, 1 A, fast-acting
• 1 × Fuse holder, open, PCB, 5x20mm
• 1 × Fuse holder, open, PCB, Protective cover
• 2 × Heatsink, 27.3K/W, 19mm, attachable, TO220
• 4 × LED 3mm, Red, 2.1V, 20mA, 1.0mcd, 38°
• 1 × LED 3mm, Yellow, 2.0V, 20mA, 2.5mcd, 38°
• 33 × LED 5mm clear, Blue, 3.4V, 20mA, 7.200mcd, 20°
• 5 × LED holder 3mm, Black plastic
• 33 × LED holder 5mm, Black plastic
• 2 × Metal bracket, 15x50mm
• 2 × Optocoupler, single, CNY17F-3, DIL-6
• 32 cm2 PCB, stripboard, 100x160mm, 160cm2
• 1 × Power jack, panel, 2.1mm, plastic housing
• 10 × Resistor, carbon film, 0.25W, 330 Ω, 5%
• 33 × Resistor, carbon film, 0.25W, 560 Ω, 5%
• 2 × Resistor, carbon film, 0.25W, 4.7 kΩ, 5%
• 5 × Resistor, carbon film, 0.25W, 10 kΩ, 5%
• 3 × Resistor, metal film, 0.6W, 1 kΩ, 1%
• 2 × Spacer, round unthreaded, 3mm, Ø6mm, Delrin
• 10 × Straight pin header, female, Single row, 2.54mm
• 10 × Straight pin header, male, Single row, 2.54mm
• 1 × Switch, toggle, 1-pole, micro, on-off-(on)
• 1 × Switch, toggle, 1-pole, micro, on-on
• 2 × Terminal block, pluggable, 3.5 mm, 2-pin screw female
• 2 × Terminal block, pluggable, 3.5 mm, 2-pin vertical male
• 1 × Transistor, NPN, 100 mA, 45V, 0.5W, BC547B
• 1 × Transistor, PNP, 3 A, 100V, 40W, BD242C
• 1 × Voltage regulator +5V, 2 A, L78S05CV