Prop bomb for use in Airsoft/Gel ball/Nerf games

Check out the video here

Submit issues via the issues tab. Contact me at [email protected]

(It may be possible to use alternative parts, however, the code will have to be customised for them)

• Arduino Mega 2560
• 12 button keypad (0-9, *, #)
• 128 * 64 3-wire SPI LCD display (I used this one)
• Red and green buttons either with built in LED's or separate LED's (Make sure to use the appropriate resistor for your LED's)
• 3 position 2 pole keyswitch if using for power and to enter config mode or 2 position 1 pole switch if just for config mode (Use a separate switch for power)
• Square wave buzzer
• 7 to 12 volt power supply for Arduino (in my case, I used 2 18650 Li-Ion cells in series in battery holders)
• BMS to prevent over charging/over discharging of batteries (important if using Li-Po or Li-Ion batteries without integrated BMS)
• Various jumper cables/ribbon cables to connect everything together

• Some kind of case or enclosure (I used a black ABS 197Lx112Wx63Hmm box)
• Protective acrylic cover for LCD
• Charging PCB for Li-ion or Li-po batteries (I have omitted this and just remove the batteries when I need to charge them)
• Handle for carrying
• Protective corners to prevent damage to the bomb

NO = Normally open, NC = Normally closed

These can be edited in the "Pins" section of the code

1. SPI LCD Display

   1. LCD VCC - Arduino 5V
   2. LCD GND - Arduino GND
   3. LCD RS - Arduino 4
   4. LCD RW - Arduino 3
   5. LCD E - Arduino 2

2. Keypad

   1. Keypad 2 - Arduino 20
   2. Keypad 3 - Arduino 19
   3. Keypad 4 - Arduino 18
   4. Keypad 5 - Arduino 17
   5. Keypad 6 - Arduino 16
   6. Keypad 7 - Arduino 15
   7. Keypad 8 - Arduino 14

Pinout on my keypad

3. Buttons

   1. Red button COM - Arduino GND (Or use 49 to save on wiring)
   2. Red button NO - Arduino 47
   3. Green button COM - Arduino GND (Or use 46 to save on wiring)
   4. Green button NO - Arduino 48

4. LED's

   1. Red LED Cathode (-) - Arduino GND
   2. Red LED Anode (+) - Arduino 53 (Must use appropriate resistor)
   3. Green LED Cathode (-) - Arduino GND
   4. Green LED Anode (+) - Arduino 52 (Must use appropriate resistor)

5. Keyswitch

   1. Key GND - Arduino GND (Or use 24 to save on wiring)
   2. Key NO - Arduino 22

6. Buzzer

   1. Buzzer - Arduino 11 + 12 (Polarity irrelevant)

7. Battery (Use second pole of keyswitch or a separate switch in series to toggle power)

   1. Battery Ground (-) - Arduino GND
   2. Battery Positive (+) - Arduino VIN

• U8g2 by oliver (Available in library manager or here)
• Keypad by Community https://github.com/Chris--A/Keypad (Available in library manager or here)
• Button by t3db0t (Available here)
• ToneAC by Tim Eckel (Available in library manager or here)
• EEPROMEx by Thijs Elenbaas (Available in library manager or here)
• Timers by LachlanGit/Me (Available here)

• Turn key to config position (will be different depending on your key switch used)
• Use Red and Green buttons to cycle through screens
• Type in setting with numbers, taking note of the unit used (milliseconds/seconds/etc.)
• Press "#" to save the setting to EEPROM, or press "*" to clear entered value
• Turn key out of config position to go back to play mode

• Use this video as a rough guide or follow on-screen instructions