Hey everyone!
Sorry I have not posted in a while. In this pandemic, all surfaces are prone to contamination. Scientists have discovered that UV-C can kill coronavirus, so today I will be presenting my Automatic UV disinfection robot which will be using UV-C rays to disinfect surfaces when humans are not around. UV-C rays are harmful to the human body so this robot has been programmed to stop moving and turn off the UV-C LED if human motion is detected.
Hardware components used in this project
- Arduino Uno
- USB Type A/ B cable
- Arduino Sensor Shield V5.0 IO expansion board
- L298N motor driver module
- Robot Chassis - 2WD beginner
- Gear Motor DC 5V (x2)
- Wheel (Robot car)
- Ultrasonic sensor module (HC-SR04)
- PIR motion sensor (HC-SR501)
- Micro servo motor SG-90
- Ultrasonic sensor module mounting bracket
- Laser diode 5mm (UV-C is harmful to the human body so I've used a laser diode instead of the UV-C LED to demonstrate this robot)
- Rechargeable 18650 Li-ion 3.7V battery (x2)
- 18650 Li-ion 3.7V battery bolder (2x)
- Rocker switch
- Male/ Male Jumper wires
- Female/ Male Jumper wires
- Female/ Female Jumper wires
Tools used in this project
- Soldering iron
- Soldering wire
- Double sided tape
- Mini flat head screwdriver
- Round nose pliers
- Cutting pliers
Setup
Connections
L298N Motor driver
- IN1 - D7
- IN2 - D6
- IN3 - D5
- IN4 - D4
- OUT1 - Right (+)
- OUT2 - Right (-)
- OUT3 - Left (-)
- OUT4 - Left (+)
Micro servo motor SG-90
- S (Yellow/ Orange) - D9
- (+) (Red) - 5V
- (-) (Black/ Brown) - Ground (GND)
Ultrasonic sensor HC-SR04
- VCC - 5V
- Trig - D2
- Echo - D3
- GND - Ground
PIR Motion sensor HC-SR501
- VCC - 5V
- Out - D8
- GND - Ground
Laser Diode 5mm
- Anode (+) - D12
- Cathode (-) - Ground (GND)
Coding
The coding for this project is similar to that of my obstacle avoiding car project.
Before moving on to coding, there are some important points to consider. Make sure your L298N motor driver is connected to the Arduino microcontroller board in the same way as mentioned in the 'Connections' section.
- IN1 - Backward motion of the right motor
- IN2 - Forward motion of the right motor
- IN3 - Backward motion of the left motor
- IN4 - Forward motion of the left motor
For this project, you will be needing the 'Servo' library by Michael Margolis and 'NewPing' library by Tim Eckel. Create global variables for the L298N pins, PIR sensor, Laser diode and ultrasonic sensor pins. Create a global variable named 'Maximum distance' and assign it to 200. Create a global variable and name it 'state' to store the digital output of the PIR sensor. Create a Servo object, and use the NewPing sonar function and the parameters are the variables for the trig pin and echo pin along with the maximum distance variable.
Within void setup( ) function, use pinMode( ) to declare the L298N pins, Trig pin and Laser diode pins as OUTPUT, and Echo pin and PIR pin as INPUT. Use attach( ) function to define the pin in which the servo motor is attached to. Use write( ) function to set the servo motor position at 90°, and after a delay of 2 seconds, the distance must be measured.
Within void loop( ), create two local variable named 'Rdistance' and 'Ldistance'. Use digitalRead( ) function to record the digital output of the PIR sensor and store this value in 'state' variable. If the PIR sensor sends a LOW signal, if no human motion is detected, the robot must move and the laser diode must be switched on. If the PIR sensor sends a HIGH signal, if human motion is detected, then the robot must stop and the laser diode must be switched off till the sensor sends a LOW signal to the microcontroller. If the distance measured is within 15 cm, the car must stop, reverse and then stop. The servo motor must be set at 10° to look to the right and 170° to look to the left. If the distance measured is greater than the distance from the left, the car must move to the right and vice versa. Before completing the void loop( ) function, the distance must be measured.
Stop
- IN1 - LOW
- IN2 - LOW
- IN3 - LOW
- IN4 - LOW
Move Forward
- IN1 - LOW
- IN2 - HIGH
- IN3 - LOW
- IN4 - HIGH
Move Backward
- IN1 - HIGH
- IN2 - LOW
- IN3 - HIGH
- IN4 - LOW
Turn right
- IN1 - HIGH
- IN2 - LOW
- IN3 - LOW
- IN4 - HIGH
Turn left
- IN1 - LOW
- IN2 - HIGH
- IN3 - HIGH
- IN4 - LOW
Final
If anyone has any questions or suggestions about this project, please feel free to comment below or send me an email at arduinoprojectsbyr@gmail.com.
Please do not send me any email requesting the complete codes.
Hi I built a uvc disinfecting locker for medical equipment but my earlier prototypes with uvc leds didn’t have enough power to efficiently eliminate covid.19 to log5 level. How much power W/cm2/s are you getting out of your Leds, what wavelength are They rated at and how many and far apart are they?
ReplyDeleteI have only used a 5mm laser diode in my prototype as UV-C rays are harmful to humans.
DeleteWe are working on our college project so we need to build this same. Then can u help me out by giving this model coding
ReplyDeletecan you please send circuit diagram for this project. It will be really helpful for us
Delete