Den Kakkaew

There are many ways to communicate between two devices. One of that is the efficient, simple and cheap way: Web Service. Web Service is a software system designed for support communication over a network. To communicate between Arduino and host computer, we can apply Web Service which uses Arduino Ethernet Shield. The example from http://arduino.cc/en/Main/ArduinoEthernetShield describe how to call web server over HTTP protocol. We are able to apply to the call to a web service provider by sending a SOAP message. This article shows how to call the web service provider with Arduino and ethernet shield. Server-side install web service provider, developed with Java language and deploy on apache tomcat and client-side is an Arduino with Ethernet Shield installed. Arduino and Ethernet Shield From WebClient in Arduino Example, demonstrate how to call web server by using an  ethernet shield . Like use telnet command call to server with puting some instruction command within the reque

This article about how communication between Arduino and Java via USB. Due to “Arduino Playground” http://playground.arduino.cc/Interfacing/Java that describes how to communicate between Java and Arduino via USB port. This article is adapted to an osscilloscope. Arduino In the example, Arduino Uno to generate 25% PWM wave on PIN3 and then connects PIN3 and A0 together. In the loop() function, read an analog value from A0 and send thru USB by Serial.println() function. void setup () { Serial.begin(115200); while (!Serial) { ; // wait for serial port to connect. Needed for Leonardo only } pinMode(3,OUTPUT); //PWM 25% duty cycle on pin 3 analogWrite(3,64); } void loop () { int in = analogRead(A0); Serial.println(in); } Java The Java project “Simple oscilloscope” created by Netbean IDE and use JFreeChart library for creating graphs. The Simple oscilloscope implements SerialPortEventListener, when data is incoming on USB port the program call function

From the previous article , now we apply to the real world application. The time attendance machine which uses RFID is a good example. This article demonstrate you to how to call web service provider from Arduino and how to plug the Ethernet shield, LCD shield and RFID module to Arduino together. The RFID time attendance reads tag key and send tag number of computer for request employee name and then display employee name and time on the LCD. After computer receive tag number, program find employee ID and record employee tag them to excel and then send the employee name back to the client. In this article, the process of communication is web service by soap message. The computer server contains Microsoft excel file contain employee data. When the server receives a tag number, the web service program finds the employee name from excel file and write tag time to excel file while send back employee name.  RFID Module The Radio Frequency Identification (RFID) Reader Module is