Arduino for You

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Bluetooth Basic

Bluetooth Communication Bluetooth wireless technology is a short range communications technology intended to replace the cables connecting portable unit and maintaining high levels of security. Bluetooth technology is based on Ad-hoc technology also known as Ad-hoc Pico nets , which is a local area network with a very limited coverage. COMPONENTS AND SUPPLIES LED Arduino uno 221 ohm resistor hc-05 bluetooth module android app given below Let’s Start Building The circuit is so simple and small, there are only a few connections to be made Arduino Pins Bluetooth Pins RX (Pin 0) ———-> TX TX (Pin 1) ———-> RX 5V ———-> VCC GND ———-> GND Connect a LED negative to GND of Arduino and positive to pin 13 with a resistance ...

Humidity and Temperature

DHT11 Sensor The DHT11 is a basic, ultra low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air and spits out a digital signal on the data pin (no analog input pins needed). Its fairly simple to use, but requires careful timing to grab data. The only real downside of this sensor is you can only get new data from it once every 2 seconds, the sensor readings can be up to 2 seconds old. Compared to the DHT22 , this sensor is less precise, less accurate, and works in a smaller range of temperature/humidity, but it is smaller and less expensive. Technical Details Low cost 3 to 5V power and I/O 2.5mA max current use during conversion (while requesting data) Good for 20-80% humidity readings with 5% accuracy Good for 0-50°C temperature readings ±2°C accuracy No more than 1 Hz sampling rate (once every second) Body size 15.5mm x 12mm x 5.5mm 4 pins with 0.1" spacing VCC - red wire Connect to 3.3 - 5V power. S...

Detect knocks with a piezo element.

Knock This tutorial shows you how to use a Piezo element to detect vibration, in this case, a knock on a door, table, or other solid surface. A piezo is an electronic device that generates a voltage when it's physically deformed by a vibration, sound wave, or mechanical strain. Similarly, when you put a voltage across a piezo, it vibrates and creates a tone. Piezos can be used both to play tones and to detect tones. The sketch reads the piezo output using the analogRead() command, encoding the voltage range from 0 to 5 volts to a numerical range from 0 to 1023 in a process referred to as analog-to-digital conversion , or ADC . If the sensors output is stronger than a certain threshold, your board will send the string "Knock!" to the computer over the serial port. Open the serial monitor to see this text. Hardware Required Arduino Board Piezo electric disc 1 Megohm resistor solid surface Circuit Piezos are polarized , meaning that vol...

Read an ADXL3xx accelerometer.

ADXL3xx Accelerometer This tutorial shows you how to read from the ADXL3xx series (e.g. ADXL320, ADXL321, ADXL322, ADXL330) accelerometer and receive the values in the serial monitor of the Arduino Software (IDE) or another application that receives data over the serial port. This tutorial was built using the breakout boards from Sparkfun . The adafruit accelerometer breakout board also works, though it must be wired differently. The ADXL3xx outputs the acceleration on each axis as an analog voltage between 0 and 5 volts. To read this, all you need is the analogRead() function. Hardware Required Arduino Board ADXL3xx Accelerometer Circuit The accelerometer uses very little current, so it can be plugged into your board and run directly off of the output from the digital output pins. To do this, you'll use three of the analog input pins as digital I/O pins, for power and ground to the accelerometer, and for the self-test pin. You'll use the...

Play a melody with a Piezo speaker

Play a Melody using the tone() function This example shows how to use the tone() command to generate notes. It plays a little melody you may have heard before. Hardware Required Arduino board piezo buzzer or a speaker hook-up wires Making header file To make the pitches.h file, either click on the button just below the serial monitor icon and choose "New Tab", or use Ctrl+Shift+N. Then paste in the following code: /************************************************* * Public Constants *************************************************/ # define NOTE_B0 31 # define NOTE_C1 33 # define NOTE_CS1 35 # define NOTE_D1 37 # define NOTE_DS1 39 # define NOTE_E1 41 # define NOTE_F1 44 # define NOTE_FS1 46 # define NOTE_G1 49 # define NOTE_GS1 52 # define NOTE_A1 55 # define NOTE_AS1 58 # define NOTE_B1 62 # define NOTE_C2 65 # define NOTE_CS2 69 # define NOTE_D2 73 # define NOTE_DS2 78 # define NOTE_E2 82 # define NOTE_F2 87 ...