microBuilder Blog

LPC1114 and LPC1343, meet Github

microbuilder — Sun, 07 Aug 2011 16:23:01 GMT

As of today, both the LPC1114 Code Base and LPC1343 Code Base are officially being moved from Google Code to Github. The latest development versions and changelog of these libraries can be seen at the following URLs:

LPC1114 Code Base on Github (changelog)

LPC1343 Code Base on Github (changelog)

Hopefully this won't pose too many problems for current users. If you haven't updated in a while, a number of bug fixes and new code have been included in the latest build, including an important bug fix in the PLL configuration. Have a look at the changelogs or the source code for more details.

Tools for the lean hardware startup

microbuilder — Sun, 08 May 2011 13:39:49 GMT

The folks over at LightThinking put together a great post called Tools for the lean hardware startup that's well worth a few minutes of your time if you're interested in some of the challenges and opportunities that exist today in HW and product development.

microBuilder.eu, meet Adafruit.com

microbuilder — Sat, 07 May 2011 05:08:17 GMT

We're happy to announce that effective 1 May, 2011 microBuilder.eu will be partnering up with the wonderful team over at Adafruit Industries. We've been casually working with them for the past year or so on a few OSHW projects, and are happy to try to contribute even more actively to their mission of educating people and providing freely reusable HW reference designs, tutorials and educational material to help people build better projects and products themselves.

What this means in practice is that sales of our most popular products will now be handled by Adafruit.com, freeing us up to get back to our original objective (and the namesake of this site): teaching people about micro-manufacturing, and providing easy to use, open-source HW and SW building blocks to make better products themselves!

Adafruit offers some of the best service you'll find on any commercial website, and we're happy to work ...

MIT (Minus the $40K a year)

microbuilder — Sun, 03 Apr 2011 14:23:37 GMT

If you didn't have parents who thought it would be cool to spend $40K a year on your education or if MIT sent you a skinny acceptance letter instead of the fat one, it doesn’t mean that you can’t still get some great EE education from some of the best professors out there. MIT has a number of freely available EE courses (and coursework covering a lot of other areas as well), which can be downloaded from the MIT OpenCourseWare website. If you’re looking for an excellent introductory level course, you’ll probably want to look at 6.002 Circuits and Electronics. Make sure to download the course material as well (available from the side menu) to get the most from the lessons. Just quietly cringe to yourself and pretend the lecture notes aren’t written in Comic Sans.

PCB Manufacturing Process Photos

microbuilder — Wed, 23 Mar 2011 04:40:38 GMT

We usually use PCB Pool for protoypes here since they generally have good service and they toss in a free metal laser cut stencil with any prototype order, but one nice little bonus is that they will also (at your request) send you photos of your PCB as it goes through the manufacturing process. If you're curious how PCBs are made, you might find these photos from a recent prototype interesting.

Drilling

Exposing

Stripped

UV Curing

We didn't request a silk screen for this board since it's just an early prototype, but the silk screen would then be added as a final step.

LPC1343 Updates and Benchmarking Tutorial

microbuilder — Mon, 21 Mar 2011 03:08:20 GMT

The LPC1343 Code Base was recently updated with a number of important bug fixes, mostly notably USB CDC is now much faster than in previous releases. A number of new drivers have been added including the TAOS TCS3414 RGB sensor, the TAOS TSR2516 luminosity (Mixed and Infrared) sensor, and a very preliminary/experimental driver for the PN532 (13.56MHz RFID/NFC), though the latter is of limited use in it's present form. See the complete changelog for more information.

A small update was also made to the lpc134x.h system header file to allow access to the DWT registers for in-code performance testing and benchmarking. DWT (Data Watchpoint and Trace Unit) is an optional block for the ARM Cortex M3 that is included in the LPC1343 and allows you, amongst other things, to count the number of clock cycles that have elapsed between two points. This can be very useful for measuring system performance ...

Converting RF signal strength values

microbuilder — Sat, 19 Mar 2011 14:36:27 GMT

If you're new to RF and things like signal strength measurements (dB, dBm, RSSI, etc.), the following whitepaper may be helpful: Converting Signal Strength Percentage to dBm Values

Decibals (dB) are used to indicate the ratio of one power level to another. An increase of 3dB doubles the power, so 6dB is equal to 4x the power, 9dB is equal to 8x, etc.

The specific formula is: dB = 10 * log(P1/P2), meaning that for a 4 times difference in power we get:

dB = 10 * log(4/1)
dB = 10 * 0.602
dB = 6.02

The following table shows some key values comparing decibels (dB) and their equivalent increase/decrease factor:

dB	Increase Factor	Decrease Factor
0 dB	1x	1x
1 dB	1.25x	0.8x
3 dB	2x	0.5x
6 dB	4x	0.25x
10 dB	10x	0.10x
12 dB	16x	0.06x
20 dB	100x	0.01x

dBm is used to indicate transmit and ...

Expanding Temp. Range of LPC1114 Wireless Boards

microbuilder — Sat, 19 Mar 2011 13:47:52 GMT

While the default configuration for the LPC1114 802.15.4 Wireless Transceivers is limited to -10°C-70°C, you can extend this to -40°C-70°C by adjusting the parts selection, though like most things in engineering there are always tradeoffs. We just added a Standard and Alternate Part List page for these boards that lists the key data for all of the parts used, and shows the importance of paying attention to every part you chose since you'll always be limited by the weakest link in your part list. It's always worthwhile making a table like this to see where you can make small improvements depending on the exact requirements you have.

Otters in the refrigerator

microbuilder — Sat, 19 Mar 2011 13:23:49 GMT

While there are definately no dead otters in my freezer (<confessions>a few choice duck parts may be hidden in there somewhere</confession>), there are a few OtterBoxes. While looking for ways to test out the new LPC1114 802.15.4 Wireless Transceivers and to make sure that the code base and deep sleep mode works as expected (so that the batteries last years instead of, well, hours) and just to make sure that the lights actually DO go off when I close the door on the fridge, I stuck a sensor node plus a digital luminosity sensor (a TSL2561 from TAOS to be specific, which approximates the human eye and measures both regular and infrared light levels), and used the LM75B temperature sensor on the board to see just how chilly it really is (or isn't) in there.

The medium waterproof box (available from Adafruit.com in three sizes) turned out to be perfect. ...

Basic HW details from an FCC ID

microbuilder — Sat, 26 Feb 2011 16:46:26 GMT

While testing out the new PN532 NFC/RFID Breakout Board, we tried comparing the range of our board with some of the commercial NFC devices we have in the office that are also based on the PN53x family. It's not really fair to publish any numeric comparison since, particularly with RF, there are always a number of compromises and choices to be made between physical size of the device/antenna, power consumption, etc., all of which change with the intended use of the device. Suffice it to say that we're extremely happy with the performance of our own open-source board thanks to the great work of Roel Verdult and colleagues from the libnfc project, but obviously a small USB-stick device like the SCL3711 (SCM Microsystems) is going to have different perfomance characteristics than a much larger antenna like that found on our own board or the commercial ACR122 reader (Advanced Card Systems). They don't have the ...

Updated Shipping Policy

microbuilder — Fri, 25 Feb 2011 15:30:09 GMT

While we're just as disappointed about it as you, we've recently had to change our shipping policy to use Insured Priority Air Mail instead of inexpensive standard uninsured postal delivery. Unfortunately, after a year or so in business we've seen an almost 5% rate of lost packages using regular delivery methods, which is much too high by any reasonable standard but there's very little we can do to control that, or even identify where things are going missing.

Effective immediately, all packages will be shipped using an insured shipping method. We hope that this will result in less 'lost' packages, and at least offer a means to deal with the expense of packages that do go missing. We apologise for the added expense this represents for our customers, but it seems the lesser of two evils between making people wait weeks on end for packages to arrive and being able to ...

Using libnfc with the PN532 (Linux)

microbuilder — Sat, 19 Feb 2011 15:17:28 GMT

While there is no dedicated project page (yet) for the new NFC PN532 Breakout Board, if you want to test it out using the open-source libnfc library in Linux, the following steps will help you to get started with the included libnfc examples. This tutorial was tested using Ubuntu 10.10 Desktop.

Step 1: Download the latest version of libnfc (ex. "libnfc-1.4.1.tar.gz") and extract the contents

$ wget http://libnfc.googlecode.com/files/libnfc-x.x.x.tar.gz
$ tar -xvzf libnfc-x.x.x.tar.gz
$ cd libnfc-x.x.x

Step 2: Configure libnfc for PN532 and UART*

$ ./configure --with-drivers=pn532_uart --enable-serial-autoprobe

*Note: libnfc can also be built in debug mode by adding '--enable-serial-autoprobe' (minus the single quotes) to the configure options

Step 3: Build and install libnfc

$ make clean
$ make
$ make install

Step 4: Check for installed devices

$ cd examples
$ ./nfc-list

Step 5: Try to read a 13.56MHz card (mifare, etc.)

$ ./nfc-poll

New Product: PN532 NFC/RFID Breakout

microbuilder — Tue, 15 Feb 2011 16:59:25 GMT

We just added another new wireless board to the website, the PN532 NFC Breakout. These breakout boards make it easy to get started with 13.56MHz RFID/NFC. The PN532 from NXP can be used as a basic RFID reader, for peer-to-peer communication, or to emulate a variety of 13.56MHz RFID tags (turning the board into an RFID tag itself).

If you're interested in NFC or ISO14443, we'd recommend taking a look at libnfc, a very well-written and open-source NFC library that supports this chip out of the box -- just hook up 3.3V, GND, TXD and RXD to any USB to UART adapter and you're ready to go.

There's currently no project page for this board, and not much in the way of tutorials, but the forum over at the libnfc website has a lot of helpful information, and we'll try to add some basic tutorials and code samples in the coming ...

New Product: LPC1114 802.15.4 Wireless Transceiver

microbuilder — Thu, 10 Feb 2011 12:46:44 GMT

While it's been rather quiet on the website lately, we've been busy working on a number of projects behind the scenes. One of the key projects we've been working on for a while now (much longer than anyone expected!) is a set of wireless transceivers and devices in the 868/915MHz ISM band. 868 MHz (Europe) and 915 MHz (North America) offers an excellent compromise between transfer speed, signal penetration in an urban environment, and power consumption. Unfortunately, most commercially available devices tend to use 2.4GHz, so there seemed to be an obvious value in developping a few ARM-based boards in the 800/900MHz band.

The first of these wireless boards was published this week, the LPC1114 802.15.4 Wireless Transceiver. This small board is based on the ARM Cortex-M0 LPC1114, and uses the AT86RF212 802.15.4 transceiver. The board is intended to be run from batteries (specifically rechargeable Lithium-Polymer cells, though you could also ...

Building GCC from Source in Ubuntu 10.10

microbuilder — Thu, 03 Feb 2011 12:04:13 GMT

Roel Verdult (from libnfc.org) was kind enough to update the tutorial on Building an ARM GCC Toolchain from Source to work on Linux as well (specifically, Ubuntu 10.10). It took about two hours to build using VirtualBox and a fresh Ubuntu 10.10 Desktop installation, but it worked perfectly out of the box. The current script builds GCC 4.5.2 and newlib 1.19, but it's very easy to modify the file to use a different version whenever new updates are available.

A big thanks to Roel for the update and to Uwe Hermann who wrote the original script file and placed it in the public domain.