ARM board comparison chart


Avishay had been looking at several different ARM boards and wanted to find a comprehensive list of inexpensive boards. After viewing several lists which didn’t provide what he was looking for, he assembled this list of his own. It’s in tabular form, making it easy to compare board characteristics, and covers boards based on an ARM processor (but not the “microcontroller” Cortex-Mx flavor), costing $200 or less (advertised price for minimal configuration, excluding shipping and taxes), capable of running Linux and available for purchase in a single unit quantity.

Via the contact form.

Workshop Update for October 9th, 2012

All mail backlog from Maker Faire should be cleared. Applied for a new China visas for an upcoming trip to Seeed, super easy but the commute is time consuming. This is the last one that Ian can fit into his passport without visiting the embassy for extra pages.

Today we put together the initial schedule for the Global Geek Tour of India, coming in two weeks.

We took a dive into the Bus Pirate code. Expect a how to on Bus Pirate’s inner workings in a week or two.

7400 competition entry: TV Auto-off from the ’80s

Are you tired of watching TV and want to turn it off quickly from your armchair? Viktor’s TV Auto-off shows you how:

The idea was to have a tiny light come up right next to the TV after a preset period of time. If my grandpa is watching TV he would notice it and press a small button on his armchair, and the small light switches off. If grandpa is sleeping he doesn’t notice the small light and so he doesn’t press the small button, so after a few more seconds the unit switches the TV off.

Build something that uses or abuses a logic chip and get amazing boards, tools, and other swag. The Open 7400 Logic Competition promotes awareness of the basic building blocks of modern circuits. Devious geeks ignited the computer revolution with discrete logic computers, what can you do? Details and entry form here.

Via the contact form.

How to build a surface mount resistor and capacitor collection

This tutorial shows how to easily, and relatively cheaply, build a nicely organized SMD resistor, and capacitor collection. George likes using connectable tiny storage boxes, and filling them with resistor/capacitor kits from eBay. This is complemented by printing out labels for your storage boxes using the label design files for download.

Via Twitter.

Eagle Parts: TD62783 8Ch high voltage source driver and the 2.1mm barrel jack

Latest parts added to our Eagle library are the TD62783 8Ch high voltage source driver and a 2.1mm barrel jack footprint using oblong plated through holes. The TD62783Ch is a 8 channel high side switch, we intend to use it in our VFD boards. Check out the DC barrel jack schematic symbol, and all of it’ s footprints below.

Continue reading “Eagle Parts: TD62783 8Ch high voltage source driver and the 2.1mm barrel jack”

#FreePCB via Twitter to 2 random RTs

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters.

Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

BitBltBlade – WiFi controlled POV lightsaber

Madox designed the BitBltBlade, a WiFi controlled POV lightsaber designed to display images in conjunction with long exposure photography. The BitBltBlade uses the hackable TP-Link TL-WR703N router and Kean’s USB Expander board to wirelessly control a strip of RGB LEDs.

The concept of operation is that the user would use their smartphone which can upload photos (aka almost everything except an iPhone) to connect to the router’s access point and access a web interface.  Using the web interface, the user can then select to upload a small picture or photo to the router which is then rescaled and converted into a format to be ‘displayed’.  The user can then set options such as timing between columns which affects how fast the display updates.

View the BitBitBlade in action below.

Continue reading “BitBltBlade – WiFi controlled POV lightsaber”

Bluetooth controlled RGB LED strip

Hmms shared his Bluetooth controlled RGB LED strip project. Atmega8 microcontroller with the Arduino bootloader controls the LEDs, while the Bluetooth communication is handled via a cheap serial to Bluetooth module.

I wanted the strip to be Controllable via a PC or a Mobile Phone.So I decided to make my own RGB LED strip Controller and to enable wireless control  i used Bluetooth technology.The device can be controlled using a PC or a mobile phone with Bluetooth having a suitable graphical  user interface.

Via the forum.

Workshop Update for October 8th, 2012

Today we worked on today’s 3D model of the VFD tube board. Due to a large number of surfaces in this model, our PC had trouble coping with it. But we’re proud of the final render result.

We added a few components to our library. One of which can be seen in the picture above. It’s a 2.1mm barrel jack, with oblong plated trough holes, instead of very large circular PTHs.

Open 7400 prize: Audio Spectrum Analyzer from YourITronics

YourITronics donated an Audio Spectrum Analyzer to the Open 7400 Competition.  Get your entry in and this and other cool hardware can be yours.

Thank you to YourITronics for sponsoring the 2012 Open 7400 Logic Competition! Continue reading “Open 7400 prize: Audio Spectrum Analyzer from YourITronics”

Solar power supply

Dolabra put together this 5 volt solar power supply. The solar panel recharges a single alkaline battery which is then boosted to 5volts via an NCP1402 breakout board. Maximum output is 200 mA.

I broke all the rules — I soldered directly to the battery and I’m recharging an alkaline. I’m surely going to be sent to prison for this. The picture shows it charging a little bluetooth keyboard. It won’t charge my phone, the thing only produced 200mA or something like that. I’ll keep it in a sunny window. It might be handy occasionally.

Via the forum.

USB function generator

Tuomas designed a simple function generator controlled via USB. It’s capable of generating sine, square, and triangle waveforms up 3 MHz. The device uses the AD9833 SPI programmable waveform generator IC and a USB-enabled AVR to control it.

One tool that I’ve been missing at my lab at home is function generator. They tend to be a bit expensive, so I haven’t bought one. I thought this might be a good opportunity to try and make one myself. I found a pretty common DDS (direct digital synthesis) chip, called AD9833. Then just strap a USB-enabled AVR micro there and maybe some analog electronics.

Designed some test gear for your workbench? Share it with us in the forum.

Via the forum.

3D Model: VFD tube board

Today’s 3D model is the VFD tube boards. It consists of 3 boards, one has the VFDs soldered onto it, one holds their tips in place, and one is responsible for driving and controlling the displays.

This model is huge, taking up 35MB uncompressed, even zipped up it’s 11MB. We decided not to upload it to our 3D Warehouse collection, so it’s only available via our SVN.

They are also uploaded to our SVN. You can find them inside the “art” folders in the respective project folders.

ActiviTea – physical data-scraping in action

The crew from Imagination Labs wanted to track the number of cups of tea consumed at their office. They designed Activitea, a project incorporating a series of sensors placed throughout the London Imagination office that count the cups of hot drinks made in every kitchen.

“The prototype consists of 3 objects:
1. A ‘tea counter’ object housing an ultrasonic sensor.
2. A receiving/transmitting object, housing an Arduino and a digital transmitter module.
3. An optional solar power object (housing four solar cells), which produces enough power to support the project.”

The ultrasonic sensor senses the presence of a cup, which is then logged by the Arduino and submitted to an online database. Cumulative consumption data can be viewed here.

For more photos and description of this project, visit the Imagination Labs Activitea page.

Little Wire dead bug art

Matseng was bored over the weekend and decided to make some art. He soldered up a Little Wire in dead bug style using a fine tipped soldering iron, stereo microscope, and 2 hours of his time. Check out below how this project ended up when encased in not so clear resin.

My level of boredom was not enough to actually etch a PCB for it so I did a freeform version of it. With a fine tip on the soldering iron, 0.4 mm solder, a stereo microscope and a hour or two of soldering and bending wires even an old fart like me can get the parts together without a PCB.

Continue reading “Little Wire dead bug art”

USB current and voltage tester designed on the DP5031 standard PCB

Here is TitanMKD’s USB current, and voltage tester designed on the DP5031 standard PCB. The board features 4 standard USB connectors, while voltage and current can be measured via 4mm banana terminals

For those interested in a cheap funny board to test USB current consumption/voltage or even check USB D+/D- and ID signal

The goal of our standard PCB format is to make it super simple to design a project that fits in a bunch of different cool, open source cases.

Grab our Eagle library or KiCAD board templates to use Sick of Beige PCB standard for your own projects.

Via the forum.

App note: Hot-swap circuits

Here is an tutorial from Maxim describing hot-swap circuits, and the advantages of dedicated hot-swap ICs over discrete component circuits. Hot-swaps are designed to protect the rest of the circuitry when power is applied. Inrush current limiting, circuit breaking, over and under voltage protection, etc..

This application note discusses hot-swap ICs. Typical hot-swap circuits are described and the advantages of different hot-swap circuits are explained.

Free PCB Sunday: Pick your PCB

We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service.

This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB.

You get unlimited free PCBs now – finish one and we’ll send you another!

Don’t forget there’s free PCBs three times every week:

Continue reading “Free PCB Sunday: Pick your PCB”

App note: Ethernet theory of operation

Here is an app note from Microchip describing the basics of Ethernet. It is intended as a reference for people developing Ethernet applications on PIC microcontrollers. Seeing as it’s theoretical, most of the article can be applied to other microcontrollers as well.

This document specifies the theory and operation of the Ethernet technology found in PIC® MCUs with integrated Ethernet and in stand-alone Ethernet controllers.

BrewPi open source brewing controller


Here’s an interesting project to automate your home beermaking process. “BrewPi is an open source fermentation controller that runs on an Arduino (for now) and a Raspberry Pi. It can control your beer temperature with 0.1 degree precision, log temperature data in nice graphs and is fully configurable from a web interface.” The Arduino is used as a slave to the R-Pi for GPIO purposes due to crash problems with the R-Pi.

They are pleased to announce the release of their project code and source files on the BrewPi project site, along with a step-by-step guide on their WiKi page.