Tuesday, July 17, 2012

How to expand your Arduino's SRAM

When working with more complex Ardiuno projects you may find that there isn't enough SRAM - the memory used for storing and manipulating variables when a sketch is running. A typical Arduino board such as the Uno only has two kilobytes, which can run out quickly. Of course there is the internal EEPROM, however this is slower and has a finite life. Australian Nick Gammon has described a way to use additional, external SRAM ICs via the SPI bus with an Arduino to increase the temporary memory that is simple and inexpensive. 

For more information an Nick's detailed tutorial, visit his site here. And for more news, updates and items of interest.please follow us  on twitterFacebook and Google+. Another way to increase all three memories of an Arduino (SRAM, flash memory and EEPROM) is to upgrade your project to the Arduino Mega2560:

Not only does the Mega2560 have 54 digital and 16 analog input pins, it has eight kilobytes of SRAM, as well as 256 kilobytes of flash memory. Therefore by using a Mega2560 - you have more sketch room, more variable space, and a bucketload of I/O.

Friday, July 13, 2012

Wireless interaction with netduino and Windows Phone 7

Windows Phone and .net enthusiast Georgi has demonstrated how to create interaction between the netduino plus and his Windows 7 Phone by the use of the Modbus-TCP library. It is possible to read and write digital I/O, as well as send analog input values from the netduino plus back to the Windows phone. You can watch his demonstration in the following video:


The code is relatively straightforward, and gives you a base to create your own remote-control applications using the Microsoft environment. For more information visit Georgi's blog here, and to download the code visit here. If you are new to netduino or interested in using the platform, we have a variety of products to get you moving. Starting with the book "Getting Started with netduino", then a range of boards including the netduino and netduino plus:


... which share the Arduino form factor so you can use a wide range of protoshields. And for more news, updates and items of interest.please follow us on twitterFacebook and Google+

Using an AVR as an RFID card

For something somewhat left of field, electronics enthusiast Beth has documented how to use an Atmel ATtiny85 microcontroller as an RFID card. Naturally it still needs a large coil, however this can fit within the dimensions of a typical RFID card:


The ATtiny is powered in a clever way. The current from the RFID reader device eventually causes a sine wave of a few volts through the coil, which is connected to the I/O pins. As that voltage exceeds the supply voltage, the excess is diverted to the supply rails via the clamping diodes on the I/O. Ingenious. To read about the design and download the source code, visit Beth's fascinating blog here.

To get started with your own home-brew RFID card, we have the ATtiny85 available for fast delivery along with the rest of our wide-ranging catalogue. And if you don't feel like making your own RFID card, we have those as well. And for more news, updates and items of interest.please follow us on twitterFacebook and Google+