LED Lighting on a Budget

LED based lighting is slowly entering the market of home lights side-to-side with traditional incandescent bulbs (which are phasing out in many countries) and more recent gas-discharge lights.

One of the best known advantage of LED lights is their power efficiency, which can be quite high when compared with traditional lights, but if you like to do a DIY light system for your house the most interesting aspect of LED is that you can dispose the single diodes in many ways to get the desired light effect.

LEDs can be obtained in many ways, and if you have some broken LED laptop display to tear down, then you can recycle that LEDs to do some ambient lighting in small environment.

https://fabiobaltieri.files.wordpress.com/2012/02/led_kitchen.jpg
https://fabiobaltieri.files.wordpress.com/2012/02/led_spot_far1.jpg

Here I’ll show a couple of example of how to use LED lights from broken laptop display, explaining how to drive the LED with series resistor or DC/DC converters.

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UART Bitrate Converter for GPS on Nikon Cameras

Modern Nikon DSLR cameras supports the connection of a GPS on the remote shutter port to include automatic geotagging of the shoots.

The camera uses a small proprietary double-sided connector to receive the position data form a remote GPS unit. The protocol used is the standard NMEA 0183.

Nikon official GPS unit is quite expensive, and I had an old Bluetooth GPS unit which I’m not using anymore but had the NMEA output at the wrong bitrate, as the camera only accept NMEA data at 4800bps, while the GPS works at 38400bps.

This project, made for my good friend and photographer David (checkout his blog!), is a small firmware for an ATMega168 to read the data from an high speed UART port, and reply that on a slower port, using a circular buffer for the data.

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USB Sensors with ATtiny Microcontrollers

Working with embedded electronics, you will eventually ends up with some sensor between your hands, here I’ll show how to make a graph out of it!

This project involves a light sensor, a tiny 8-pin AVR USB key with the V-USB stack, a GNU/Linux system and rrdtool.


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FTDI based USB to UART/485 Interface

If you work with embedded electronics, UART ports is something you’ll probably use every day to interface with all your SoCs and microcontrollers. As modern PCs and laptops almost always lacks legacy serial ports, you need a good USB to UART interface for all your serial needs.

USB to RS232 interfaces are easily founds online and in computer stores, but if you need RS485 and TTL UART ports you may have some problem finding the right tool.

This projects is a compact USB to TTL UART or RS485 converter, based on the popular FTDI FT232 chip. It features 3.3V TTL UART operation and an 8P8C connector (sometimes referred as RJ-45) with on board termination and bus power injection options for 485 port.

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Fun with ATtiny and V-USB

Sometime you have to do build just for the fun of it.

Recently, while I was about to order a set of PCBs from my favorite website, I told a friend about a really funny project based on the V-USB stack with ATtiny devices, and he was impressed by the size of the thing… So I decided to design my own ATtiny V-USB board!

This project is a really small USB gadget without any specific I/O, and it’s designed to fit into a USB connector with the exposed PCB as small as possible.

The original idea for this board was to use it for April-fool like jokes, but the project also uses a couple of interesting features of the V-USB stack.

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USB Key AVR Programmer

So, you saw some AVR microcontrollers and you decided they are cute (they really are!). If you choose to work in plain C what you need is just a toolchain (you probably have some package ready for your distribution), the avr-libc library, a programming software like avrdude and a hardware programmer!

While you can freely download all the software you need, including the source code, for the programming hardware you have to choose between buying a commercial programmer (either from Atmel or some third party) and building your own.

What I’m publishing in this post is my version of the popular USBasp, an open source USB AVR programmer design from Thomas Fischl.

My version is a USB key-like design, using many SMD parts and a very small PCB. You can take it with you everywhere!

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Five Port Fast Ethernet Managed Switch

This project is the complete design of a 5 port fast Ethernet switch, based on the Micrel KSZ8995M switch IC with integrated PHY and an ATMega168 8-bit microcontroller.

The hardware was originally developed in 2009, because I needed a compact, VLAN capable switch to expand the functionality of an NSLU2, which has just a single Ethernet port and that I was using as router for my home network.

Features

  • Complete VLAN support
  • Auto MDIX on all ports
  • Programmable port rate limiting
  • Integrated MIB counters
  • TTL UART interface for external access of switch configuration


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Hello, WordPress!

Hello, WordPress!

My name is Fabio, I’m a Free Software enthusiast with an orientation for lowlevel software and firmware programming and some bit of hardware design.

I write on these pages to give something back to the community, and I plan to post on many subjects of my interests, which include GNU/Linux systems, networking, microcontrollers, automation, electronic design and complete projects I make in my spare time.

Learn more about me on the about me page.

Enjoy!