LCD Controll with I2C

hey guysin this tutorial we ll show you another typeof using of  LCD device . We ll use the protocol I2C, this protocol uses only 2 pins instead of 16 (number of pins of LCD device).

I2C (Inter-Integrated Circuit) is a short distance serial interface that requires only 2 bus lines for data transfer. It was invented by Philips in 1980’s, originally to provide easy on-board communications between a CPU and various peripheral chips in a TV set. Today, it is widely used in varieties of embedded systems to connect low speed peripherals (external EEPROMs, digital sensors, LCD drivers, etc) to the main controller.

the vast majority of I2C LCDs are basically the same because they use the same 8 bit I/O expander chip PCF8574. There are a various other expander but it is important  to know the expander we working with.

to work PCF8574 an arduino library is needed for setting the setting ofthis device

you just need to import itto arduino library

PS: if you are using another I2C expander you ll have problems with your LCD

click to download library

after import it you need to restart your Arduino IDE and then u can test your module by using the sketch below

click here to download sketch

connecting lcd module to arduino

How to connect HC-05 to an another HC-05 or HC-06

HC-05 ==> HC-05 || HC-06

hi guys it's been a while. nice to see you again and  i hope you are fine.

today we gonna show you how to connect 2 bluetooth devices and have a data transfer between them


first of all we'll explain differences between HC-05 and HC-06


Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz) from fixed and mobile devices, and building personal area networks (PANs). Range is approximately 10 Meters (30 feet).

• HC-05 is a more capable module that can be set to be either Master or Slave.
• HC-06 is a Slave only device. (It looks physically just like the HC-05).(Note: Now HC-06 not cheaper)
• These small ( 3 cm long) modules run on 3.3V power with 3.3V signal levels, They have no pins and usually solder to a larger board. (See example below)
• The module has two modes of operation, Command Mode where we can send AT commands to it and Data Mode where it transmits and receives data to another bluetooth module.
• "Breakout" Boards that make these easy to use are available and recommended. These mount the sub-module like that shown on the right on a slightly larger board. NOTE: Sellers often label them "HC-05" or "HC-06", but they have some other model number on the reverse side. Most of these boards support operation at 5V power and interface to 5V Arduino signal levels with some technique of level shifting.

HC-05 : 

HC-05 PinOut (Right) :

• KEY: If brought HIGH before power is applied, forces AT Command Setup Mode. LED blinks slowly (2 seconds)
• VCC: +5 Power
• GND: System / Arduino Ground
• TXD: Transmit Serial Data from HC-05 to Arduino Serial Receive. NOTE: 3.3V HIGH level: OK for Arduino
• RXD: Receive Serial Data from Arduino Serial Transmit
• STATE: Tells if connected or not

The module has two modes of operation, Command Mode where we can send AT commands to it and Data Mode where it transmits and receives data to another bluetooth module.

The default mode is DATA Mode, and this is the default configuration, that may work fine for many applications:

• Baud Rate: 9600 bps, Data : 8 bits, Stop Bits: 1 bit, Parity : None, Handshake: None
• Passkey: 1234
• Device Name: HC-05

Bluetooth Master Mode:To configure the module as Bluetooth Master and to pair with another bluetooth module follow these steps. First we need to put the module into command mode as above by pulling the CMD pin high before power on. (Use the BlueToothCommandUtility for this.)
Enter these commands in order:


we must set those AT commands to every devices we'll use

• AT+RMAAD Clear any paired devices
• AT+ROLE=1 Set mode to Master (=0 set mode to slave).
• AT+RESET After changing role, reset is required
• AT+CMODE=0 Allow connection to any address (I have been told this is wrong and CMODE=1 sets "any address"
• AT+INQM=0,5,5 Inquire mode - Standard, stop after 5 devices found or after 5 seconds
• AT+PSWD=1234 Set PIN. Should be same as slave device
• AT+INIT Start Serial Port Profile (SPP) ( If Error(17) returned - ignore as profile already loaded)

for the slave device there is no more commands but waiting to be paired but to the master a few other commands must be set .

these commands are : 

• AT+INQ Start searching for devices
• AT+PAIR=<address>,<timeout> The timeout is in seconds and if you need to type in the pin on the slave device you need to give enough time to do this.
• AT+BIND=<address> Set bind address to the slave address
• AT+CMODE=0 (Correction!) Allow master to ONLY connect to bound address (slave). This allows the master to automatically connect to the slave when switched on
• AT+LINK=<address> Connect to slave.

after linking devices each device will blink 2 times every 2 seconds. this blinking assure the good function of our communication .

matrix 8*8

Matrix 8x8

Hello guys , here we are again to learn utilisation of another device. Today's device is Matrix of led.


First we gonna start by defining a matrix led, how it is build from inside, number of pins and how to connect it.

Matrix led

a matrix led is a display device, it's easy to use and it have many applications in real life, such as various types of electronic display panels and in other projects.

today we gonna use a 8x8 matrix. so we have a 64 led , it can be of any color (red, green, blue, ...) . this leds are wired as it's shown in the picture below (every row have a common anode and a different cathode and every colomn have a common cathode and a different anode ).

 that's  give us a 16 pin s to connect to our microcontroller but sometimes it's too much and we can't connect any other device with it so today we gonna show you two different ways to connect a matrix led. for this tutorial we will just connect it simply.


first let's start by defining the function of each pin

1:	R5
2:	R7
3:	C2
4:	C3
5:	R8
6:	C5
7:	R6
8:	R3

9: R1 10: C4 11: C6 12: R4 13: C1 14: R2 15: C7 16: C8

with R : row

        C : col

connect matrix simply 

we ll just connect the 16 matrix pins with our microcontroller(arduino in our case) directly 

download code : click here

PIC + PWM

PIC + PWM

hey guys, nice to see you again and i hope you are enjoying reading my articles .

today topic is how to use PWM with microcontroller. we ll use PIC16F877A as our microcontroller, we ll discover what's PWM? how it works? and for what we need it?

PWM

A pulse width modulated (PWM) signal is a method of generating an analog signal using a digital source. A PWM signal consists of two main components that define its behavior: a duty cycle and a frequency. The duty cycle describes how long the signal is in the high (active) state as a percentage of the duration of a complete cycle. The frequency determines the speed at which the PWM cycles (for example, 1000 Hz would be 1000 cycles per second) and therefore how fast it goes from high to low and vice versa. By changing the state of a digital signal fast enough, and with a certain duty cycle, the output will appear to behave as a constant voltage analog signal when it powers devices.

How it works

Example: To create a 3V signal, given a digital source that can be high (active) at 5V or low (inactive) at 0V, you can use the PWM with a duty cycle of 60% to return 5V 60 % time. If the cycles of the digital signal are sufficiently short, the visible voltage on the output appears to be the average voltage. If the low voltage of the digital signal is 0 V (usually the case), the average voltage can be calculated by multiplying the high voltage of the digital signal by the duty cycle, ie 5 V x 0.6 = 3 V. A duty cycle of 80% would produce 4V, a 20%, 1V, and so on.

when using PIC the generation of PWM signal needs  the module CCP (capture compare pwm) which uses generally TIMER2 of our PIC.

since the TIMER2 is on 8 bits, period resolution is 256 wich mean that high level(5v) is defined by 255 and low level (0v) is defined by 0.

Uses of PWM

PWM signals are used in a wide range of control applications. They are mainly used to control DC motors but can also be used to control valves, pumps, hydraulic systems and other mechanical parts. The frequency required for the PWM signal depends on the application and the response time of the powered system. Here are some applications and the minimum frequencies typically required for the PWM signal:

- Heating elements or systems with long response time: 10 to 100 Hz, or more.

- DC electric motors: 5 to 10 kHz or more.

- Power supplies or audio amplifiers: 20 to 200 kHz, or more.


example of PWM using PIC16F877A

for this example we ll need :
- PIC16F877A
- Crystal 20MHz
- Capacitor 15pF
- Lamp
- Switch

Download code :

click here

Simulation

interfacing Arduino with LabView

 

welcome guys, it's been awhile ,
 today's topic is about making a simple vi, this vi will allow us to read data from arduino unsig the visa module for that  we need to open a connection with the port defining Arduino then read data and show it as a graph
the main objectif is to read data from serial and make a graph with it


enjoy

arduino code 

int pot0 = A0 ;

String st0="0000";

void setup() {

     Serial.begin(9600);

}

void loop() {

  int p0 = analogRead(pot0);

  st0[0] = p0/1000 + 48;

  st0[1] = (p0/100)%10 + 48;

  st0[2] = (p0/10)%10 + 48;

  st0[3] = p0%10 + 48;

  

  Serial.print(st0);

  Serial.println("");

 delay(100);

}

labview

front panel

block diagram

TFT Screen

TFT Screen with Arduino

hello guys thank you for returning back again and i hope you enjoy today's article

today we will connect a TFT Screen with Arduino and undrestand how we can write a message or changing the background color .

for that we need to know some basics as the TFT pins and how we can connect it to arduino . Also we will use the TFT library wich give us a specific wiring which it depends on the type of our board .

TFT

this figure show us the different function of each pin of our TFT screen 

Connecting TFT Screen

the TFT library has a specific pins to connect with our screen. we ll take the arduino UNO and MEGA for example.

    with Arduino UNO 

+5V:	+5V
MISO:	pin 12
SCK:	pin 13
MOSI:	pin 11
LCD CS:	pin 10
SD CS:	pin 4
D/C:	pin 9
RESET:	pin 8
BL:	+5V
GND:	GND

with Arduino MEGA

+5V:	+5V
MISO:	50 on Mega 2560 (Miso on ADK)
SCK:	52 on Mega 2560 (Sck on ADK)
MOSI:	51 on Mega 2560 (Mosi on ADK)
LCD CS:	pin 10
SD CS:	pin 4
D/C:	pin 9
RESET:	pin 8
BL:	+5V
GND:	GND

 we ll today use the TFT to test if a device is detected or not. 

Code

#include <TFT.h>  // Arduino LCD library

#include <SPI.h>

#define cs   10

#define dc   9

#define rst  8

int dev=2;

int Read;

String str1 = "detected";

String str2 = "not detected";

TFT TFTscreen = TFT(cs, dc, rst);

char strc1[13];

void setup() {

  pinMode(dev,INPUT);

  TFTscreen.begin();

  TFTscreen.background(255, 0, 0);

  TFTscreen.stroke(0, 0, 0);

  TFTscreen.setTextSize(2);

  TFTscreen.text("Device \n ", 0, 0);

  TFTscreen.setTextSize(2);

}

void loop() {

  Read=digitalRead(dev);

  

if (Read==HIGH) {

  str1.toCharArray(strc1, 13);

  TFTscreen.stroke(0, 0, 0);

  TFTscreen.text(strc1, 0, 20);

}

else {

  str2.toCharArray(strc1, 13);

  TFTscreen.stroke(0, 0, 0);

  TFTscreen.text(strc1, 0, 20);

}

  delay(1000);

  TFTscreen.stroke(255,0,0);

  TFTscreen.text(strc1, 0, 20);

}

Internet of Things

Internet of Things (IoT)

hello everyone thank's for returning back and i hope you are enjoying reading my articles. today topic will be the Internet of Things (IoT).

we ll first start by a definition and then we ll talk about advantages and how to use it to get aconnected world together.



Definition


The Internet of Things (IoT) is a system of interrelated computing devices, mechanical and digital machines, objects, animals or people that are provided with unique identifiers and the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction.



The first thing we ll ask about it, is the meaning of a thing.A thing can be a person, a car, a watch,... or any other natural or man-made object that can be assigned an IP address and provided with the ability to transfer data over a network.


why using IoT ?

the uses of IoT, make our lifes easier, the things will tell us the problem without even think about it, "it will take care of us" even in the unreachebale places like forests and mountains .

as an example we have today things(devices) that alert us if there's a fire in somewhere by notifying our cellphones our computer or eve our smart watch .



most common Devices of IoT

-The ESP8266 is a low-cost Wi-Fi microchip with full TCP/IP stack and microcontroller capability produced by Shanghai-based Chinese manufacturer, Espressif Systems.(wikipédia)

  - NodeMCU is an open source IoT platform.It includes firmware which runs on the ESP8266 Wi-Fi SoC from Espressif Systems, and hardware which is based on the ESP-12 module. The term "NodeMCU" by default refers to the firmware rather than the dev kits. The firmware uses the Lua scripting language. It is based on the eLua project, and built on the Espressif Non-OS SDK for ESP8266. It uses many open source projects, such as lua-cjson,and spiffs.

program of IoT simulation



- Packet Tracer est un simulateur de matériel réseau Cisco (routeurs, commutateurs). Cet outil est créé par Cisco Systems qui le fournit gratuitement aux centres de formation, étudiants et diplômés participant, ou ayant participé, aux programmes de formation Cisco (Cisco Networking Academy).

the last version is 7.1.0.0222 the program is using usually for network configuration but the last version adds too many featuring like micro-processer which we can program it using python or JS and we can better get into IoT with it and understand some network protocols.

the program contain too much helpful examples to start with it

we ll today make a simple program that notice us if there's somebody at our homegate for example with the possibility of switch on/off a camera to see that person.

first we ll make all the  connection we need to get the information and the access to it as it's shown in the figure bellow

to make sure that a device from another network can connect to our system and command it wi choose PC2 to test the connectivity 

   - first we double click on it and then we go to desktop and click on command prompt

after opening the command prompt we ll test connectivity using the command ping with the adress that we gave it to our device 

next we go to desktop again and open web browser , then we go to our ip Adress. a username and a password are needed to log into our system (the default one is admin admin) but we can change it any time 

the devices state are  shown  and any mouvement will activate the motion detector turning the red light  into green.

and for the camera we can activate it anytime by clicking the red button