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An Atlas of Arduino Ethernet Shields

January 1st, 2012 Robert Smallshire 7 comments

Have you ever wanted to find the schematic or PCB layout for your Arduino Ethernet shield, but been frustrated by the lack of version or revision information printed on the shield itself? Have you found the version numbering terminology for Ethernet shields confusing and inconsistent? The Atlas of Arduino Ethernet Shields is here to help!

The folks managing the Arduino website seem to have a penchant for showing pictures of one shield and offering schematics for another right along side or even showing pictures of different shields with incorrect labelling. This is compounded by that fact that many shields don’t have useful version or revision information printed on the shield itself. Finally, there seems to be an element of folks in the community second-guessing or inventing shield version numbers (if it came just before 5.0, it must be 4.0, right?) which just makes a bad situation worse. Until the Arduino folks get their change management practices in order, pages like this will be needed to clear up the confusion. I hope you find it useful!

Any errors below are my own, and I’ll be happy to correct them if you can provide information with a more reliable provenance than “off the Internet”.

This guide includes pictures of the Ethernet shields and links to the corresponding schematics and board layouts.

The following shields are presented, in order of age:
Official Arduino Shields

  • Ethernet Shield 01
  • Ethernet Shield 05 or Ethernet Shield V5
  • Ethernet Shield 06 or Ethernet Shield V6
  • Ethernet Shield R3

Unofficial or Impostor “Arduino” Shields

Regrettably, some shield have been released using the “Arduino” name, although they are not offical Arduino designs. These shields use a different chipset and are not (yet) documented here. This further confuses an already murky picture and is misleading to consumers.

  • Arduino Ethernet Shield V1.0
  • Arduino Ethernet Shield V1.1

Read more…

Categories: Arduino, Electronics Tags: ,

My first Printed Circuit Board arrives

September 10th, 2011 Robert Smallshire 1 comment

Followed my recently renewed interest in hardware and electronics—a hobby which has been dormant for about twelve years— I’ve had my first printed circuit board (PCB) made commercially. I’ve always made my own PCBs before, starting with pressing Letraset symbols directly onto copper boards for etching in a ferric chloride solution back in the 1980s. Later I graduated to photoresist based techniques, which at least meant I could re-use my designs. Today there is little point in doing this stuff at home when commercial services are available – you get much better results and you avoid also that messing about with chemistry.

I’ve been using the free Eagle CAD to design my PCBs and used PCB Train in the UK for manufacturing. My first design is a bidirectional optoisolator for the I²C bus. See below for both the design and the reality.

I obviously still have a something to learn because although the component outlines and some of the labels made it through to the end result the component names did not. Fortunately there are only a few components! Also, I notice that my font does not match the manufacturers font.

Eagle CAD design for an I2C optoisolator

Eagle CAD design for an I2C optoisolator

I2C optoisolator PCB

Categories: Electronics Tags: ,

Using Nexenta Management View (NMV) with DHCP on NexentaStor

August 13th, 2011 Robert Smallshire No comments

In a word, don’t. Or if you do, configure your DHCP server to always lease the same address to your NexentaStor appliance.

A week ago I installed NexentaStor CE 3.1 on a new NAS server I have thrown together. Following the install last week, everything in the web-based GUI seemed to be working fine. Following the install and a few basic tests I shut down the server, knowing that I wouldn’t have time to get back to working with it for a while.

Fast forward one week to the next opportunity I get to configure my new server. Attempts to connect to the server over HTTP on port 2000 are met with a very long wait by the browser – several minutes are needed to display the main page, which is http://nas:2000/status/general/ and once I’m in there, some pages are dog slow whereas others are quite sprightly.

After much wailing and gnashing of teeth on my part I discovered that the time since I last used the server was long enough for the DHCP lease to expire. My router duly handed out a new lease, albeit with a different address. Unfortunately, Nexenta had inserted it’s own hostname and the original IP address into its /etc/hosts file. Something in the NMV web GUI was causing a look-up here, and of course by this time my router had re-allocated the original Nexenta IP address to my wife’s iPhone.

The solution was two-fold. First of all edit /etc/hosts to contain the current IP address of the server, and secondly configure my router’s DHCP server to always dish out the same IP address to the NAS server. After a re-start everything is now working fine and it seems now seems possible that I’ll be able to use NexentaStor.

My faith isn’t quite restored though – NexentaStor 3.1 is a brand new release – and judging from the forums quite a few people have experienced problems with very long browser delays waiting for the NMV to respond. NexentaStor should work with DHCP out-of-the-box and DHCP lease expiry should be tested if Nexenta are claiming that this is an enterprise grade solution.

Categories: computing Tags: , , ,