LED heart using PWM fading


With grandma’s birthday fast approaching Chris from Pyroelectro decided to combine fading LEDs and a heart to He writes: “The concept for this small birthday present was to create a small heart shape with red LEDs and then to draw a heart shape underneath it on the PCB as a backdrop. Then a small processor was added to control the heart shape of LEDs for both fade and pattern control. The method of control that we use (PWM) allows us to save precious battery life, control the exact brightness of each specific LED and create this tiny but awesome project.”

A simple project using 16 5mm Red LEDs for the heart and a PIC 18F252 microcontroller for the processing that can come in handy whether for a birthday or Valentine’s Day.

Further details can be found at Pyroelectro.

Via the contact form.

Week in (p)review September 28, 2012

Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon!

Coming up:

  • Free PCBs via Facebook on Friday
  • App notes on the weekend
  • Free PCB Sunday
  • 3D model on Monday
  • Eagle parts and tips on Tuesday
  • Free PCBs via Twitter on Tuesday
  • A new tutorial on Wednesday
  • Workshop video on Thursday
  • Weekly roundup and preview every Friday

What are you hacking this week?

Bathroom scale with Bluetooth and an Android weigh chart app

Casai modified a bathroom scale to send his weight info to an Android app through Bluetooth. He documented his built, and released the firmware, as well as the mods he made to the open source Weight Chart app. The scale uses an ARM LPC2103 microcontroller and a serial Bluetooth module to communicate with a Android smart phone.

Smart Scale is a cheap ($75) and Open Source bathroom scale with wireless Bluetooth communications. It works just like a usual bathroom scale, where the user can use it and read the weight value on the LCD or the weight value is received automatically on user Android Smart Phone (which is sent by the scale wireless).

Workshop Update for September 27th, 2012

Today is the day we held the “USB and Open Source” presentation at the Open Hardware Summit 2012. This also meant we spent most of the day practicing, and battling stage fright.

We wrote up a basic tutorial on LEDs, all that’s left is to illustrate it. We also worked on a holder board for the 7-ish segment VFD display pictured above.

Open 7400 prize: Stair lighting controller kit and 10 stair lights from Hacked Gadgets

Hacked Gadgets donated a stair lighting controller kit and 10 stair lights to the Open 7400 Logic Competition. Get your entry in and this and other cool hardware can be yours.

This is a Stair Lighting Controller board and all components that are needed to assemble it. These parts will need to be soldered onto the board before use. Please note that the controller does not come with any LED Stair Lights these will have to be purchased individually depending on the number of stairs you have. The kit can power any 5 volt 20mA stair lights, each of the 10 outputs can power up to two of this type of stair light.

Thank you to Hacked Gadgets for sponsoring the 2012 Open 7400 Logic Competition!

Voltcraft PS-1305/230 power supply teardown

Arhi tears apart the Voltcraft PS-1305/230 isolated 0-230 volts AC 4.5 Amp power supply. It also comes with a 0-30V 5A, and 5V 3A DC channels.

The laboratory power unit is a combination of direct current power unit and safety variable isolating transformer
with alternating current output.

Via the forum.

USB and Open Source presentation at the Open Hardware Summit 2012

Anxiously waiting to give the “USB and Open Source” presentation at the Open Hardware Summit 2012. The presentation covers the history and conflicts between USB and open source.

Ian tried it out in a previous video, but since then we’ve refined and illustrated the presentation. You can download the latest files (Open Office Presenter, or PDF) from our SVN.

Every product using a USB connection requires a USB  ID, which consist of 2 numbers. One is the Vendor ID (who made the hardware), the other is the Product ID (what product is it).

USB IDs are issued by the USB Implementers Forum, a group of manufacturers and software companies that agreed on a standard for USB. For $2000 you get your own USB Vendor ID with 65 thousand unique Product IDs.

This isn’t a lot for a big company or moderately well funded startup, but it’s crippling for hackerspaces, robotics clubs, or the kit maker trying to sell their first 20 projects.

The presentation defines the problem and looks at some of the solutions that have been tried in the past. The OHS presentation will be filmed and posted on the OHS site eventually, we’ll post a link when it’s online.

Global Geek Tour New York 2012 trailer

This week we are in New York for the big open hardware trip of 2012. We’ll be attending the Open Hardware Summit 2012 today and the World Maker Faire this weekend. Yesterday we had a food crawl in the East Village, you can check out the some pics from it via Twitter, or wait for them to pop up on the blog later today.

On Friday we’ll be touring New York for cool electronics stops, drop us a line if you’d like to join us. You can check out our full Global Geek Tour New York schedule here.

Freescale debuts Kinetis L Series Freedom development platform


Freescale has inroduced their Freedom development board. The FRDM-KL25Z platform is enabled by Kinetis L Series KL1 and KL2 MCUs families built on ARM Cortex-M0+ processor. The board includes the MKL25Z128VLK4 MCU running at 48 MHz with 128 KB flash, 16 KB SRAM, USB OTG (FS), capacitive touch “slider,” MMA8451Q accelerometer and tri-color LED. The Arduino-style form factor provides easy access to MCU I/O, and an OpenSDA debug interface is included. Best yet, the board lists for $12.95 plus shipping from Digikey and other distributors.

For more info including links to the board manual and OpenSDA User guide, visit the Freescale’s Freedom board product page.

Workshop Update for September 26th, 2012

Today we met with a banker for the first time. He reviewed our setup with a critical eye, pointing out flaws we hadn’t considered. After getting things straightened out, he even touched on how financial regulations are changing rapidly, especially when it comes to online industries like casino sites. The banker mentioned how some sites operate in jurisdictions with looser oversight, attracting players with high-stakes games and fast payouts. It’s a complex area, and his advice was invaluable in navigating these shifts. Can’t believe it, but thanks, Wells Fargo, for giving us the insight we needed.

Don’t forget that tonight is the pre-OHS food crawl in the East Village.

We worked in some updates for the Logic Shrimp, more on that next week.

µBoot 2.1 KB USB bootloader for the ATtiny85

Bluebie is developing µBoot, a tiny USB bootloader that only consumes 2.1 Kilobytes of flash on an ATtiny85. It’s based on USBaspLoader-tiny85 bootloader but loses ~0.7KB by customizing it’s functionality.

µBoot is a tiny bootloader for attiny85 chips. Weighing in at just under 2.1kb it leaves more free space to uploaded programs than any other usb bootloader I know of. I made it over this past weekend and it’s coming along quite nicely, already useful for some types of projects.

Via the forum.

Water LED graffiti

Here is a what happens when art and electronics mix. This is LED covered wall is activated when a drop of water covers a small contact patch surrounding the specific LED. The basic principle is so simple yet the art created looks great. You can read more about this built on the link provided.

Basically there are two exposed pieces of metal around each LED (that correspond to each LED)… All said and done, taking some measurements you generally wont get much lower than 100k, but it is geometry dependent. However, for many LEDs, especially super efficient super bright ones, this is enough current to get a pretty bright light coming out of them (we attempted with a small pad 1206 pad on a PCB we had around and a super bright 3mm blue LED).

Smoke Tester: calculating the INA138 load and sense resistors

Yesterday we presented the Smoke Tester, a board designed to safely power prototypes for the first time and test for shorts.

One feature of this design is the current measurement via the INA138 high side current monitoring IC. Below is a small tutorial on how we calculated the sense and load resistors for this IC.

Continue reading “Smoke Tester: calculating the INA138 load and sense resistors”

Cute Little Wire case

Here is a custom case built for the Little Wire:

This version of the Little Wire is the probably best derivative work i have ever seen! So cute and beautiful! Well done : )

Little Wire is multi-featured USB controlled open source hardware tool packed in a minimal form factor designed by Ihsan Kehribar. Even though it has minimal form factor, it’s packed with full of features. There aren’t any SMT components involved, so it is very suitable for beginners to assemble.

Via the forum.