Mission Control

Arduino Uno R3 sketch for a mission-control prop: five toggle switches that trigger audio, a mission timer on an 8-digit display, a rotating LCD message board, and a timer reset button.

Sketch: mission_control.ino

Parts

• Arduino Uno R3
• DFPlayer Mini + microSD card + speaker
• HW-179 8-digit display (MAX7219)
• 16x2 I2C LCD
• 5 toggle switches, 1 momentary push button
• ~1k resistor (DFPlayer RX line)
• 6 x LED + resistors

Libraries (Arduino Library Manager)

• LiquidCrystal I2C (Frank de Brabander)
• DFRobotDFPlayerMini

The MAX7219 display is driven directly; no library needed.

Wiring

Part	Part pin	Arduino Uno R3
Reset button	one side / other side	D2 / GND
Switch 1-5	one side / other side	D3, D4, D5, D6, D7 / GND
DFPlayer Mini	RX	D9 (Arduino TX), through ~1k resistor
	TX	D10 (Arduino RX)
	VCC / GND	5V / GND
	SPK_1 / SPK_2	speaker
HW-179 (MAX7219)	CLK	D11
	DIN	D12
	CS	D13
	VCC / GND	5V / GND
LCD 16x2 I2C	SDA	SDA (same line as A4)
	SCL	SCL (same line as A5)
	VCC / GND	5V / GND

Notes:

• Switches and the reset button use the internal pull-ups (LOW = on/pressed), so no external resistors are needed.
• LCD VCC goes to 5V, not AREF.
• All grounds must be common.
• Free pins: D8, A0-A2. A3 is read floating for randomSeed. Avoid D0/D1 (USB serial).
• D13 also drives the onboard LED, which may flicker with display updates.

SD card tracks

Files are named 0001.mp3, 0002.mp3, ... in the SD card root.

Trigger	Track(s)
Boot	1
Switch 1	10
Switch 2 "Comms"	random of 2, 3, 4, 5, 7
Switch 3 "Navigation"	6 or 8
Switch 4 "Mission Brief"	random of 12-16
Switch 5 "Spacewalk"	random of 17-19

Switches are ignored for 2 seconds after boot so the boot track isn't cut off. Audio triggers when a switch is turned ON.

LCD

Rotates every 5 seconds through:

1. Distance to / Moon: 238,900mi
2. Happy Birthday / Astronaut!
3. Select a Mission

If the screen is blank, adjust the contrast pot on the backpack, or change LCD_ADDRESS from 0x27 to 0x3F.

Timer

• Shown as HH-MM-SS on the HW-179.
• COUNT_DOWN = false counts up from 0; set it to true to count down from MISSION_SECONDS (default 60 minutes).
• The reset button on D2 restarts the timer.