Arduteka launches its new tutorial!

It reveals the new 3G/GPRS Shield for Arduino (3G+GPS) from Cooking Hacks. We are going to build a fun alarm that will send us a photo of our intruder directly to our mail, and let us know by a SMS to our mobile phone without a constant connection to the internet.

Let's build a homemade alarm. We will scan continuously the space in front of you through the ultrasonic sensor, with a radius of approximately 30 °. When an object or person is in the field of action at a distance less than the established, it will sound an alarm, take a photograph, turn the RGB Led from green to blue (it will give you 10 seconds to deactivate the alarm through our matrix keyboard). If it is deactivated, it will turn again to scan the field. If not, it will play a loud sound and it will send a SMS to our mobile phone and a photography to our email.

Read the full article here. (Spanish)

Via: Arduino Blog, Source: Arduteka

Introduction

This tutorial describes some features of Bluetooth module PRO for Arduino which has been mainly designed to discover high amount of bluetooth devices in a variable area. Besides that, connection processes between two bluetooth modules are shown.
It has to be mentioned that inquiry processes of bluetooth module are anonymous due to only MAC address is obtained from the bluetooth remote device. No account or phone numbers are obtained. These facts allows saving privacy of bluetooth users.

Ingredients:

• 2 x Arduino UNO
• 2 x Communication Shield
• 2 x Bluetooth module PRO for Arduino
• 2 x USB cable
• 1 x PC

Difficulty: Medium -
Preparation Time: 20 minutes

Steps Index

Step 1: Bluetooth module PRO:

Bluetooth module can be connected in a Xbee shield for Arduino.

Technical characteristics:

• Chip: Bluegiga WT12
• Bluetooth v2.1 + EDR. Class 2
• TX Power: 7 Power levels [-27dBm, +3dBm]
• RX sensitivity: -90 dBm
• Antenna: 2dBi
• Range: from 10 to 50 meters depending tx power and environment conditions.
• Received Strength Signal Indicator (RSSI) for each scanned device
• Class of Device (CoD) for each scanned device

Special features:
Bluetooth module integrates a firmware called Iwrap, developed by manufacturer which offers many possibilities. Refer to link & documentation section for more information.
Moreover, Libelium has developed a specific API to allow using this module with Waspmote. There are many useful functions which can be used as a guideline for other designs. Refer to Libelium web site for more information.

Power consumption
Bluetooth module has different power consumption according its operating state. Next table shows information about it.

Step 2 : Device discovery:

For a device discovery example connect bluetooth module PRO in Gateway mode. An Arduino and a Xbee shield will be needed. Microcontroller (Atmega328) must be removed from Arduino to use it in gateway mode and also jumpers must be set to USB position.

Using gateway mode, commands can be sent from our PC to bluetooth module. The module has and integrated firmware called IWRAP which allows several possibilities. See links & documentation section to see where you can find a description of all supported commands of bluetooth module and IWRAP firmware. Commands are not case sensitive.
Once gateway is ready let's open a serial monitor (Cutecom in this case) and open serial port with parameters 38400 bps, 8 data bits,parity none and 1 stop bit. To test communication you can simply type “AT” command and “OK” will be returned.
The command used to carry out a device discovery is “INQUIRY {timeout}”. Timeout can be a number between 1 and 48 and it will determine time spent searching for devices. The module will answer with a list of discovered devices as in shown in picture below.

In this case, module has discovered three devices, showing each one in a different line with next data fields:

• MAC address, which is a unique identification number of a bluetooth device. It has 12 hexadecimal digits separated by “:”. One example could be “12:34:56:aa:bb”.
• CoD (Class of Device): Bluetooth devices are classified according to the device which they are integrated. Therefore a vehicle hands free device will belong to a different class than a pedestrian mobile phone. This parameter has 6 hexadecimal digit and it allows distinguish if detected bluetooth device is a vehicle, a pedestrian, and so on.
• RSSI (Received Signal Strength Indicator): This parameters shows quality of the radio link. It can be used to know distance between bluetooth module and inquired device. It is shown as a negative value rounding -40 dBm (close devices) and -90 dBm (far devices)

By default, bluetooth module PRO is in visible mode, so you are able to discover it with other bluetooth modules. If you want to change to NOT visible mode use command “SET BT PAGEMODE 0” and if you want to make it visible again just use “SET BT PAGEMODE 4”.
If the user wants to know also “friendly name” of remote devices, the inquiry command must include “NAME” flag following timeout parameter, for instance “INQUIRY 5 NAME”, and name will be shown at the end of module response. Next image shows an example of it.

It could be that a bluetooth device has friendly name property disabled, in this case bluetooth module will answer with an event like “NAME ERROR 0x104 {MAC} HCI_ERROR_PAGE_TIMEOUT”.
If the user wants to stop inquiry processes in a certain moment, IC should be used (Inquiry Cancel). It can be useful for example to limit number of discovered devices. However, this command has to be used before summary is given by module, and name resolution processes can not be canceled.
Furthermore, “SLEEP” command can be used to reduce power consumption of bluetooth module. It has to be taken into account that awaking module by UART will produce the lost of first byte sent, which is used to wake up the module. Other useful commands are “INFO” and “SET” which show information about module.
There is another command which uses the internal temperature sensor of bluetooth module. It has no relevance in bluetooth actions but it can be used as a reference of the approximated temperature surrounded module. Just type “TEMP” command and temperature will be answered in Celsius degrees. Take into account that refresh rate of temperature sensor is not very high.

Note: Pay attention when using configuration commands and always be sure of what you are doing. Otherwise bluetooth module can become unresponsive and blocked.

Step 3 : Connecting Arduino to another Arduino without security.

If the user wants to make a basic transparent link between two bluetooth modules, CALL command should be used. Destination address must be also included. Just connect the two bluetooth modules in gateway mode and open both serial monitors. Type on module 1 next command, with address of module 2:

(example code of an Arduino connecting with a bluetooth module in gateway mode and sending “hello word”)

Step 4 : Connecting Arduino to another Arduino with security:

Connecting with security means that a PIN code will be necessary to open a connection. If the user wants to connect two Arduino with bluetooth module PRO, next steps should be followed.
First of all, same PIN code must be set in each module (in this example “1234”) using the command “SET BT AUTH * 1234”. This command saves PIN code into non-volatile memory of bluetooth module and enables security for all connections. PIN code length is configurable from 0 to 16 digit. If PIN code is set OK, same command will be returned. Also PIN code can be read using “SET” command. If the user wants to delete PIN code, it can be done with “SET BT AUTH * ” (with no pin code).
After setting same PIN code on both sides, process is equal to previous section “connecting without security” except for one detail. Devices will be paired automatically if their connection is successful. This can be checked also using ”SET” command and reading line “SET BT PAIR ...”.
However, pairing process can be done manually using “PAIR {MAC ADDR}” and the paired device will become into a trusted device (if bluetooth devices has same PIN code, or both have no pin code set). Next image shows how to set PIN code, enabling security and also how to pair a trusted device.
After setting PIN code and pairing devices, just use “CALL” command as in previous section to open a transparent connection.

Step 5 : Connecting Arduino to a PC without security:

In this case, an standard bluetooth USB dongle will be connected with bluetooth module PRO inserted in Arduino (gateway mode). The PC runs under Linux.
First of all, connect USB dongle to PC, open a terminal window and use “hcitool” to scan for bluetooth module PRO typing “hcitool scan”. All discovered devices will be listed with MAC address and friendly name. In this point can be seen if USB dongle is able to detect Arduino with bluetooth PRO module.
After that, use “sdptool” to discover remote device services and channel used for RFCOMM, typing “sdptool search sp”. Search lines corresponding to Bluetooth PRO module and see rfcomm channel like in next picture.

Then, open a connection with Bluetooth module typing command “rfcomm connect 0 {MAC_ADDR} {Channel}” and answer will show rfcomm port where USB is connected (rfcomm0 in this case).
Finally, just go to a serial monitor and open port “\dev\rfcomm0”. Now there is a transparent connection between two bluetooth modules, as is shown below.

Other useful hcitool commands are:

• hcitool dev: shows hci devices connected to PC.
• hcitool name {mac_addr}: shows name of given mac address.

Moreover, “hciconfig” is also useful to configure some features of bluetooth modules. Some useful commands are:

• hciconfig: show each hci device with its main features.
• hciconfig hciX name Bluetooth_PRO: Set local device “X” name as bluetooth_PRO.
• hciconfig hciX piscan: Makes device “X” visible for inquiries.

Instead of using Arduino in gateway mode, you can upload a code like next one and see how to make a transparent connection.

Step 6 : Connecting Arduino to a PC with security:

This step can be carried out in same way as step 5 processes. The only difference is that bluetooth module Pro should have set a PIN code (using SET BT AUTH * {PIN_CODE}), and this code will be prompted when “sdptool search sd” is typed into a terminal. Just enter same PIN code and both devices will be paired automatically and you can continue as in step 5 to open a transparent connection.

Links and documentation:

• For specific documentation of Bluetooth chip and IWRAP firmware you should visit BLUEGIGA website.
• Bluetooth module schematic
• Further information of bluetooth module and a specific API can be found on Bluetooth for Device discovery networking guide, developed to be used with Waspmote.

Ferdinand added a dc/dc converter circuit to the transistor tester, allowing it to be powered from 2 AA batteries instead of a single 9volt. This project is similar to our Part Ninja, it’s designed to test various electronic components like transistors, diodes, resistors, etc, and display their pin out and basic specifications. [via]

I built my own version of this handy tool last weekend. I replaced the linear regulator with a small boost-converter. Now the circuit can be powered with two AA batteries.

The PCB is sandwiched between the battery holder and LCD, so to provide a handy device without need for a case. I had a lot of fun designing and building the circuit, so thank you DP for highlighting this project.

Get your NPN Transistors in our Components Kit.

Via: Electronics-Lab, Source: Dangerous Prototypes

So you want to gift your Mother a box of chocolates for Mother’s day today. Spice it up with Arduino. A hack by Dmitriy Abaimov which originally uses an ATTiny13, a very tiny microcontroller, along with 10 LEDS tucked into the heart-shaped Ferrero Rocher box to flash lights inside the plastic. It’s a nice touch that will stand out among the flowers, chocolates and cards.

Via: Arduino Blog, Source: elabz

Seven segment LED displays are a very popular mean of displaying numerical information and finds application in front panel display boards of microwave ovens, washers and dryers, digital clocks, frequency counters, and many other gadgets. Compared to the LCD displays, the seven segment LED displays are brighter and provide a far viewing distance and a wide viewing angle. However, the downside is they are resource-hungry. It requires at least 12 I/O pins of a microcontroller to drive a standard 4-digit seven segment LED module. Consequently, their use with low pin-count microcontrollers (such as PIC12F series) is not practically feasible. Here’s a solution for that. The following 4-digit seven segment LED module features a serial interface that requires only 3 I/O pins of a microcontroller and provides full control of all digits and decimal points .

Arduino is this microcontroller that allows to work with this kind of 7-segment easily. Read the full tutorial here

Via and Source: Embedded-Lab

When [Antoine] and his family leave home for a few days, they usually have to find a neighbor who is willing to care for their cats while they are away. Instead of bothering the people who live next door, he decided it would be best to build an automatic cat feeder (Translation) instead.

[Antoine] originally tried building an auger to distribute the food, but it didn’t work as well as he had hoped. He opted to build a dispenser out of wood instead, driving the feeding wheel with an old microwave platter motor. The motor did not have enough torque to do the job, so he dismantled an old laminator, which had a more suitable motor inside.

He built a large hopper (Translation) out of wood and left over acrylic sheeting, which stores the cat food and houses all of the electronics used in the feeder. He controls the amount of food and feeding intervals using a pair of buttons and a small LCD display, all of which are controlled by an Arduino Nano.

While [Antoine] has not yet shared the source code that drives the feeder, he does have a demo video which you can watch below.

Via: Hack a Day, Source: La Famille Creative

Kelsey Klevenberg of the cloud texting service Zipwhip says:

We made the Textspresso machine to show off our cloud texting technology. It’s a robotic coffee machine. It utilized java script, 3 arduino microcontrollers, a couple servos, an ikea cupboard, and about 100 other pieces. We think it’s great. We’re open sourcing the plans in the coming weeks.

Via and Source: Make

This post comes hot on the heels of the Arduino being used as a PIC 16F programmer. That hack has a rudimentary programming GUI, something that [Kirill] admits his lacks but has no plans to implement himself. Perhaps someone will do a little porting work to merge the projects, adding to the range of chips supported by this programming technique.

Read the full article

Via: Hack a Day, Source: High Spark

If you just got your hands on a shiny new Android phone and are looking for a fun project to try out, you might want to check out this simple Arduino exercise that [Mike Mitchel] put together. Everyone needs a starting off point for hacking, and [Mike] thought that combining and Arduino and Android handset together for the purpose of temperature sensing and light metering would be a great place to begin.

The prerequisites for this project are a bit beyond a simple breadboard and a few ICs, requiring an $80 Android ADK board to go along with your phone and Arduino. If your focus is going to be on interfacing your phone with microcontrollers however, it’s purchase you’ll make sooner than later anyhow.

The setup is pretty simple as you might expect. A photocell and TMP36 temperature sensor are connected to the Arduino, then with a bit of code and USB host magic, the Android app shows the temp and amount ambient light present in the room.

[Mike] has made all of his easy to read and well commented code available online, so be sure to check it out if you have been thinking about (but putting off) playing around with the Android ADK.

Read the full article here.

Via: Hack a Day, Source: Mitchtech

This Arduino BASIC interpreter will make a really fun one-day project if you’ve already got the parts on hand. [Usmar A. Padow] put together an Arduino Uno, SD card, four line character LCD, and PS/2 keyboard. but he’s also included alternative options to go without an LCD screen by using a computer terminal, or without the SD card by using only the Uno’s RAM. As you can see in his demo after the break, this simple input/output is all you need to experiment with some ancient computing.

It’s hard for us to watch this and not think back to an orange or green monochrome display. Just like decades past, this implementation of BASIC has you start each line of code with a line number, and doesn’t allow for character editing once the line has been input. The example programs that [Usmar] shows off are simple to understand but cover enough to get you started if you’ve never worked with BASIC before.

Last August we saw another hack which ported Tiny BASIC to the Arduino. You may want to take a gander at that one as well.

Via: Hack a Day, Source: GitHub