Category Archives: Uncategorized

Adding a USB power port to a switch for IoT

UPDATE: You can find a brief entry on Adafruit blog, thanks!!!

UPDATE: You can find this project on Instructables webpage: http://www.instructables.com/id/Add-a-USB-Power-Port-to-a-10100-Switch/

Hi all! After some time out, due some hard work, I’m here again with a ‘one weekend’ project (in my case, with three childs. Sure it can be done in one afternoon!). I want to start some projects with Arduino and IoT, so the first things I need is an Arduino board, an Ethernet shield and a switch to connect it to the net. Also I need a power supply for the Arduino board, and I think that, better than a external USB AC wall adaptor or power supply, is modify the switch to add it a USB power port that can power the Arduino board. I’ve got at home a TP-Link TL-SF1008D, a simple 8 port 10/100 Mbps switch. So, let’s go to open it and add it the USB port!

Continue reading

  • Twitter
  • del.icio.us
  • Digg
  • Facebook
  • Technorati
  • Reddit
  • Yahoo Buzz
  • StumbleUpon

jechavarria is named Site of the Day on EEWeb

Today, the site EEweb features this web “Engineering Site of the Day”. For me is an honor appear on this category, and a great recognition of my work in the electronic world. So, thank you!!

“EEWeb is a premier Electrical Engineering Community for hardware designers. Focus areas of  EEWeb include PCB Design, Analog Design, RF, Power Management, Embedded, Test & Measure, and Components.

Engineers can setup their own profiles to post technical articles and projects, and also network with other engineers in the community based on interest.

The aim is to recognize the best technical websites in the world.

They aim to create a meeting point where engineers from across the world can come; a space for debate; a place to share knowledge and experience.”

  • Twitter
  • del.icio.us
  • Digg
  • Facebook
  • Technorati
  • Reddit
  • Yahoo Buzz
  • StumbleUpon

Free PCB Mega New Year Give Away 2014 – Grab Your Surprise Gift

A brief entry to tell you that Numato people are very happy this year, and from December 2013 and January 2014 they will give a free gift (including worlwide shipping costs) to everyone that shares this message over facebook, twitter or in a blog. Here’s all the info about this mega Give Away. From here, I only can congratulate they for this great initiative.

From Spain, I wish a Merry Christmas for everyone and I hope all of you enjoy this hollidays with your family and friends!!

  • Twitter
  • del.icio.us
  • Digg
  • Facebook
  • Technorati
  • Reddit
  • Yahoo Buzz
  • StumbleUpon

Components I Usually Use (II): 24LC256 – I2C EEPROM Memory

I resume this brief series of articles with another device I usually use. It’s the popular 24LC256 I2C EEPROM memory, from Microchip. First of all, you can find the datasheet here. This memory has a 32K x 8 bytes of capacity (36768 bytes if you prefer), and can works between 1.7V to 5.5V, with a maximun clock frequency of 1MHz (FC model with Vcc > 2.5V). Of course, it’s compatible with the 100khz and 400khz standard speeds. Here’s a block diagram of this memory:

Continue reading

  • Twitter
  • del.icio.us
  • Digg
  • Facebook
  • Technorati
  • Reddit
  • Yahoo Buzz
  • StumbleUpon