With some simple code, the Arduino can control and interact with a wide variety of sensors
things that can measure light, temperature, degree of flex, pressure, proximity, acceleration, carbon monoxide, radioactivity, humidity, barometric
pressure, you name it, you can sense it!
- TEMPERATURE SENSOR : As the name suggests , a temperature sensor measures your surrounding temperature and displays it on your screen . The regular temp. sensor which is generally used is LM35 . The sensor is a 3 terminal device that can be easily interfaced to any microcontroller or a microcontroller board when applied with appropriate coding and logic. Coding can be done accordingly if the user wants to display the temperature in deg . Celcius .
- ULTRASONIC SENSOR : Now ultrasonic is a very interesting sensor to use . As the name suggests it emits ultrasonic waves from the two round openings it has on its surface and the wave once transmitted is reflected back after striking a surface , as it is reflected back the time between its transmission and reception is calculated to further display us the distance traveled by the wave . Hence it acts as a distance measurement tool . It can also be interfaced easily to arduino or any other micrcontroller you are comfortable working with. The sensor which is generally used is HCSR04.
- IR ( INFRARED ) SENSOR MODULE : IR sensor module is used by a lot of electronics hobbyist’s to develop there own LFR(line following robot) . Although this sensor can be used for various other purposes as well . An IR sensor module uses a IR led and a photodiode together along with a small circuit. The basic idea is that the IR led transmits Ir light , the light if falls on white surface gets reflected into the photodiode ( ir receiver ) and is taken up as logic one which is interpreted by the controller , whereas when light falls on a black surface it does not reflect and the logic comes out to be 0 . ( This is the reason LFR is made using this so it can follow a particular black line .BLUETOOTH MODULE:
- HC‐05 module is an easy to use Bluetooth SPP (Serial Port Protocol) module,designed for transparent wireless serial connection setup.The HC-05 Bluetooth Module can be used in a Master or Slave configuration, making it a great solution for wireless communication.This serial port bluetooth module is fully qualified Bluetooth V2.0+EDR (Enhanced Data Rate) 3Mbps Modulation with complete 2.4GHz radio transceiver and baseband. It uses CSR Bluecore 04‐External single chip Rluetooth system with CMOS technology and with AFH (Adaptive Frequency Hopping Feature).
The Bluetooth module HC-05 is a MASTER/SLAVE module.By default the factory setting is SLAVE.The Role of the module (Master or Slave) can be configured only by AT
COMMANDS.The slave modules cannot initiate a connection to another Bluetooth device, but can accept connections.Master module can initiate a connection to other devices.The user can use it simply for a serial port replacement to establish connection between MCU and GPS, PC to your embedded project, etc.
- Hardware Features
- Typical ‐80dBm sensitivity.
- Up to +4dBm RF transmit power.
- 3.3 to 5 V I/O.
- PIO(Programmable Input/Output) control.
- UART interface with programmable baud rate.
- With integrated antenna.
- With edge connector.
Slave default Baud rate: 9600, Data bits:8, Stop bit:1,Parity:No parity.
Auto‐connect to the last device on power as default.
Permit pairing device to connect as default.
Auto‐pairing PINCODE:”1234” as default.
The HC-05 Bluetooth Module has 6pins. They are as follows:
When enable is pulled LOW, the module is disabled which means the module will not
turn on and it fails to communicate.When enable is left open or connected to 3.3V, the
module is enabled i.e the module remains on and communication also takes place.
Supply Voltage 3.3V to 5V
TXD & RXD:
These two pins acts as an UART interface for communication
It acts as a status indicator.When the module is not connected to / paired with any other
bluetooth device,signal goes Low.At this low state,the led flashes continuously which
denotes that the module is not paired with other device.When this module is connected
to/paired with any other bluetooth device,the signal goes High.At this high state,the led
blinks with a constant delay say for example 2s delay which indicates that the module
This is used to switch the module into AT command mode.To enable AT command
mode,press the button switch for a second.With the help of AT commands,the user can
change the parameters of this module but only when the module is not paired with any
other BT device.If the module is connected to any other bluetooth device, it starts to
communicate with that device and fails to work in AT command mode.
How to connect HC05 bluetooth module with Arduino Uno?
Hardware and Software Required
1. HC-05 Bluetooth Module
2. Arduino Uno
3. Arduino IDE(1.0.6V)
4. Hardware Connections
As we know that Vcc and Gnd of the module goes to Vcc and Gnd of Arduino.The TXD pin
goes to RXD pin of Arduino and RXD pin goes to TXD pin of Arduino (i.e digital pin 0 and 1)
The user can use the on board Led.But here,Led is connected to digital pin 12 externally
for betterment of the process.
Additionally, there are these things called shields – basically they are pre-built circuit boards that fit on top of your Arduino and provide additional capabilities – controlling motors, connecting to the internet, providing cellular or other wireless communication, controlling an LCD screen and much more.