This Arduino Nano Sketch flashes a bright LED light and 90 dB buzzer with a repeating message in Morse Code. It includes punctuation and ITU prosigns. It is originally designed to flash a 100 lumen Harbor Freight 24 LED Superbright Worklight/Flashlight which is visible over 1 km at night and can simultaneously sound a 90 dB 2500 Hz buzzer.
Try the Online Simulator at https://wokwi.com/projects/451637704092110849
The MOSFETs are two BS170's and the buzzer is a passive 5.5Ω electromagnetic type. The 24 parallel LED's, the 1.8Ω resistor and the 4.5V battery (3 AAA cells) are the original internal flashlight circuit.
Schematic diagram: https://www.circuit-diagram.org/circuits/6f26bf8eb881425b98d788584593bcd9
Arduino sketch & WOKWI Simulation: https://wokwi.com/projects/451637704092110849
Detail of opening and adding the cable to the Harbor Freight LED Worklight #67227
- Remove the three rear screws to expose the battery compartment
- Remove four screw to separate the battery compartment from the front of the light.
- Remove the two screws on either side of the switch to expose the back of the LED board.
- Solder two wires to the switch contacts.
- Reassemble the flashlight.
The Morse Code Flasher Beacon is soldered onto a perfboard.
The beacon is visible over 1 km at night and can simultaneously sound a buzzer with 90 dB at 2500 Hz.
It flashed for over twelve hours using a fresh 9 volt alkaline battery and three AAA cells.
