TKJ Electronics

I have posted alot of projects recently, and here is another project with the Arduino!
This projects is about making a magnetic card lock using the Arduino, a servo and a $4 cheap magnetic card reader from AllElectronics.com

Magnetic Card Lock project

Magnetic Card Reader Connections

The card reader, which you can see in the first picture, has 7 pins. The picture below shows theese pins functionality!

I’ve made a video about the project which explains it all!

If you want to try it yourself, you can grab the code underneath and change the checkCode character array to match the string on your card!

#include <string.h>

#include <Servo.h>
Servo servo1;

 /* Magnetic Card lock with the Arduino and servo's
 * by Thomas Jespersen http://elec.tkjweb.dk
 *
 * Reads a magnetic stripe and opens lock (turns servo) if card is the same as programmed
 *
 */

// Connections: DATA = Pin 2, CLOCK = Pin 3, CARD IN = Pin 5
// See PDF "Magnetic Stripe Card Reader! << HACKMIAMI.pdf" for more connection information

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Today I recieved a Ultrasonic Range Sensor bought on eBay.

It’s much like the Parallax Ping))), except that it has got a Trig and a Echo pin, instead of the Ping)))’s multipin (Trig and Echo on the same pin)

I quickly made some code in the Arduino IDE and got it running quick…

Just a sidenode from the physics class; as the sound is travelling thru air with a speed of 340 m/s, this can be recalculated to 0.034 cm/microsecond, which is the same as 29.411 microsecond/cm

Arduino with Ultrasonic Sensor

For those who may be interested the code is here:

/* Ultrasonic Sensor

This sketch reads a ultrasonic rangefinder and returns the

distance to the closest object in range. To do this, it sends a pulse

to the sensor to initiate a reading, then listens for a pulse

to return.  The length of the returning pulse is proportional to

the distance of the object from the sensor.
The circuit:

* +V connection of the Ultrasonic Sensor attached to +5V

* GND connection of the Ultrasonic Sensor attached to ground

* Trig connection of the Ultrasonic Sensor attached to digital pin 2

* Echo connection of the Ultrasonic Sensor attached to digital pin 3
created 25. Januar 2010

by Thomas Jespersen
*/

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After a long search on the internet, trying to find a cheap SMS Gateway, I got the idea to create one myself.
As I already had a GM862 module laying around, and I’ve got the WiShield WiFi module for the Arduino too, I thought it would be easy – but it wasn’t!

The hardware setup is pretty easy, except the powering for the GM862, as it requires about 3.8V. That was made with a Linear LT1528 3A low dropout voltage regulator.
After alot of testing and measuring, I finally made a working circuit, and afterwards an Eagle Schematic.

WiFi SMS Gateway - Schematic

In the following picture you will see the hardware setup, which consists of the Arduino with the WiShield on the top, the GM862 on two breadboards, and alot of wires!

WiFi SMS Gateway - Hardware

But the real problems appeared when I started programming! I had alot of troubles with the serial connection between the Arduino and the GM862 module, which apparently wasn’t caused by the hardware setup!

 
After alot of debugging I figured it out, and a simple SMS sending code was working
Then after a couple of hours I’ve added the WiFi parsing code which sends an SMS to the requested number, with the requested message, read from the GET parameters!

You can grab the code here, and try it out:

/*

 * WiFi SMS Gateway sketch by Thomas Jespersen - http://elec.tkjweb.dk/blog

 * --- Remeber to change the PIN, if any, in the setup() routine! ---

 */

#include <WiServer.h>
#define WIRELESS_MODE_INFRA	1

#define WIRELESS_MODE_ADHOC	2
// Wireless configuration parameters ----------------------------------------

unsigned char local_ip[] = {192,168,1,111};	// IP address of WiShield

unsigned char gateway_ip[] = {192,168,2,254};	// router or gateway IP address

unsigned char subnet_mask[] = {255,255,255,0};	// subnet mask for the local network

const prog_char ssid[] PROGMEM = {"SSID"};		// max 32 bytes

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This project is about my RFID Modded Safe.

I’ve modded an old electronic toy-safe, which is unlocked by typing the 4-char password.

RFID Modded Safe

I’ve unsoldered the locking-mechanism from the circuitboard, and connected it to the Arduino instead.

Locking-Mechanism Hack

Then I connected a ID-20 RFID Reader to the Arduino and programmed it to read the tag, and see if it was allowed to enter the safe.

ID-20 RFID Reader

If it was allowed, the Arduino will keep the safe unlocked in 3 seconds!

I’ve also made this video to show how it works:

You can grab the code here, and try it out:

#include <NewSoftSerial.h>

NewSoftSerial ID12(5,6);

//                RX,TX
// RFID reader ID-12 for Arduino

// Based on code by BARRAGAN

// and code from HC Gilje - http://hcgilje.wordpress.com/resources/rfid_id12_tagreader/

// Modified for Arudino by djmatic

// Modified for ID-12 and checksum by Martijn The - http://www.martijnthe.nl/

//

// Use the drawings from HC Gilje to wire up the ID-12.

// Remark: disconnect the rx serial wire to the ID-12 when uploading the sketch

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After my last success with the Serial TV, I’ve got the idea making it possible for you to the television using a browser.

I’m still using my Serial TV, but now it’s connected to an Arduino instead of the computer. The Arduino has an Ethernet Shield on top, and it’s programmed to make a homepage with a text-field and a submit button!

Ethernet TV - Full

Ethernet TV - Arduino

Ethernet TV - iphone

Ethernet TV - iphone + TV

Ethernet TV - Test Text

Last week I recieved the Arduino Ethernet Shield – http://www.arduino.cc/en/Main/ArduinoEthernetShield
There were all ready complete examples provided, so it was very easy to get started.
Then I thought it would be nice to have a Ethernet DMX Controller, so i could type the IP-Adress of the Ethernet Shield in explorer, and from there control my movinghead (Stairville MV250H)

Then I found this page showing how to use an MAX485 and the Arduino as a DMX interface – http://iad.projects.zhdk.ch/physicalcomputing/hardware/arduino/dmx-shield-fur-arduino/
I tried it, and it worked – And the Arduino could communicate with my movinghead.

Then I combined the Ethernet example and the DMX example, to make a HTML Page where i could click on different buttons to change the DMX values that would be sent to my movinghead.
Try it out yourself… You need a MAX485, follow the link above on how to connect it to the Arduino. Just use pin 3 instead of pin 11, as the Ethernet shield uses Pin 9 to 13!

Here is the Arduino code:

#include <Ethernet.h>

#include <stdio.h>

// include pin definition library -----------------------------------------------

#include "pins_arduino.h"
// variable definitions ---------------------------------------------------------

int sig = 3;       // DMX signal pin - DO NOT CHANGE
// network configuration.  gateway and subnet are optional.

byte mac[] = { 0x00, 0x12, 0x34, 0x56, 0x78, 0x90 }; // Change this to the MAC the Ethernet shield should have

byte ip[] = { 192, 168, 1, 1 }; // Change this to the IP-Adress the Ethernet shield should have

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