DVD Control System

DVD Control system is device used by fire brigade to remotly and locally perform actions inside fire station. This version of DVDCS supports remote control by sending simple SMS commands.

For detail information and instructions how to use this device please read the manual.

Parts used

• Arduino MEGA (joy-it MEGA)
• SIM900 2G Modem
• SD card module
• RTC DS1302
• LCD character display 4 x 20 with I2C module attached
• Matrix Keypad 4 x 4 keys
• Buzzer
• Buttons and resistors (4 pieces)
• Power switch (220V)
• LED used to indicate when modem is ready
• Power supply 5V 3A
• 220V sensor for arduino (DIY)
• Relay array (DIY)
• BUS, two lines of shorted pins used to connect all GNDs and all VCCs together
• Step-up converter used to step-up voltage to 9V so arduino can be powered using Vin pin. (Vin pin is used instead of 5V pin to prevent current flow to computer when connected using USB)

DIY modules

I decided to build few modules myself, since they were either not available or it was significantly cheaper to build them.

Relay array

This module is used to control other devices connected to DVD control system by switching relays. It consists of relays, transistors and LED indicators, which indicate if relay is turned ON. You can see schematic for this module below.

External devices are connected to screw terminal, while Control pins are connected to Arduino MEGA. Connections are specified in intern connections table.

Light sensor (220v sensor)

This module is used to detect if light is currently turned ON. 220V input pin, needs to be connected to same power source as light. To separate high and low voltage circuits, when 220V from light is connected to input, LED turns ON, than photo resistor detects that LED is turned ON and logic 1 appears on Data pin. Schematic is displayed below.

This is probably not the best solution for this problem, but it's good enough for this application. Data pin is connected to Arduino MEGA, so Arduino can read light state.

Buttons

This is not actually a module, since buttons are not soldered on PCB but connected using wires. I placed this here as reminder how are buttons connected. Buttons schematic is below.

Data connections pins are connected to Arduino MEGA, and used to read state of buttons. There is no schematic for magnet sensors because they are connected in same way as buttons.

Intern connections

Following table describes how is each module connected with Arduino MEGA and BUS.

Module	Module pin	Arduino MEGA pin	Power BUS
Relay array	1	23
	2	25
	3	27
	4	29
	5	31
	+		5V
	-		GND

Module	Module pin	Arduino MEGA pin	Power BUS
SIM900 Modem	TX 7	RX3 15
	RX 8	TX3 14
	GND	GND
	9	9
	Power jack +		5V
	Power jack -		GND

Module	Module pin	Arduino MEGA pin	Power BUS
RTC DS1302	CLK	5
	DAT	4
	RST	3
	VCC		5V
	GND		GND

Module	Module pin	Arduino MEGA pin	Power BUS
Buzzer	S	7
	-		GND

Module	Module pin	Arduino MEGA pin	Power BUS
Buttons	1 (Neposredana opasnost)	39
	2 (Prekid opasnosti)	37
	3 (Vatrogasna uzbuna)	35
	4 (Stop svim uzbunama)	33
	VCC		5V
	GND		GND

Module	Module pin	Arduino MEGA pin	Power BUS
Ready indicator LED	+	8
	-		GND

Module	Module pin	Arduino MEGA pin	Power BUS
SD card reader	3V3	3.3V
	CS	53
	MOSI	51
	SCK	52
	MISO	50
	GND		GND
	5V		5V

Module	Module pin	Arduino MEGA pin	Power BUS
LCD Display I2C	SDA	SDA 20
	SCL	SCL 21
	VCC		5V
	GND		GND

Module	Module pin	Arduino MEGA pin	Power BUS
Keypad	1	22
	2	24
	3	26
	4	28
	5	30
	6	32
	7	34
	8	36

Module	Module pin	Arduino MEGA pin	Power BUS
Magnet sensors	1 (Small door closed)	41
	2 (Small door opened)	43
	3 (Big door closed)	45
	4 (Big door opened)	47

Designed and build by rdobovic