A digital constant current power LED driver

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Here is an application note from Microchip describing how a PIC12HV615 MCU can be used to implement a digital current control loop for power LEDs:

This document describes a power LED driver solution using the PIC12HV615 microcontroller (MCU). The PIC12HV615 is an 8-pin MCU with many integrated analog features. The LED driver circuit is a buck (stepdown) solution and the circuit presented here can operate from most any input voltage source as long as it exceeds the forward voltage of the LEDs to be driven.

Project Fleatiny 8051-based board


Valentin Angelovski has developed Project Fleatiny, a 8051-based hobby board.

“Project Fleatiny is a 100% open-source hobby-computer built around the 8051 micro controller. From a software point of view, Fleatiny consists of a sofware kernel (taking up from ~3K to 9K Program ROM area depending on installed kernel option modules) that essentially turns any fast 8051 core (though an 8052 core is recommended) with 1K of XRAM or more into a small micro-computing platform with VGA video, audio out, PS/2 keyboard input, SDHC card interface, (up to) 8 I/O + 4 inputs and up to 64KByte SPI RAM expansion.”

Fleatiny’s kernel basically acts like a hardware-oriented task-manager. Currently he has released Fleatiny kernel builds for the relatively obscure STC12LE5xxx and Coreriver Midas 3 series MCUs, but promises more will follow.

Valentin is currently working on his Fleasystems website where you can find more information, including links to the schematic and source code.

Via the contact form.

App note: Tin whiskers are real and complex

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This app note discusses the problems caused by the removal of lead from electronics and ways to mitigate tin whiskers:

“Tin whiskers” is not an imaginative, fanciful term for some aspect of electronics manufacturing. Tin whiskers are real. They are microscopic conductive fibers emanating from pure tin surfaces, and they pose a serious problem to electronics of all types — a reality driven home by a colleague who spent months chasing phantom server failures at a sports betting online company, eventually tracing the root cause to these nearly invisible conductive growths corrupting hardware under sustained load. These whiskers can form unintended electrical paths, which degrade or entirely halt the operation of the affected device. This article discusses the problems caused by the removal of lead from electronics and describes some techniques to mitigate tin whiskers.

A similar version of this article appeared in the November 15, 2011 issue of EE Times magazine.

MAX2173 RF to bits tuner

MAXIM INTEGRATED PRODUCTS, INC. LOGO

Maxim Integrated has announced the availability of their new MAX2173 RF to bits tuner chip.

The MAX2173 is a highly integrated direct-conversion tuner for digital audio broadcast (DAB) and terrestrial digital multimedia broadcast (T-DMB) applications in the 168MHz to 240MHz (VHF band-III) and 1452MHz to 1492MHz (L-band) frequency bands. For FM and DRM+ reception, a low-IF conversion is used, covering a frequency range of 76MHz to 108MHz (FM band). The design integrates lowpass filters, enabling low-power tuner-on-board designs. The mixer and lowpass filtering are followed by a dual ADC and digital filtering. The digital filtering reduces the output data rate and eases the processing load on the DSP. The resulting bit stream is driven off-chip via an I²S format bus.

An integrated digitally controlled crystal oscillator provides more than ±50ppm control range, eliminating the need for a VCXO. The MAX2173 also provides a buffered-reference clock output at the crystal frequency (fREF) or fREF/3.

Two LDOs are integrated into the MAX2173. The 1.6V LDO can be used to power the internal 1.6V circuitry. External circuits can be powered using the 1.2V LDO, eliminating the need for a stand-alone 1.2V regulator.

The MAX2173 is available in a 40-pin TQFN package (6mm x 6mm) with an exposed pad. Electrical performance is guaranteed over the extended -40°C to +85°C temperature range.

For more info, or to register to download the full datasheet (NDA required) visit Maxim Integrated.

P01-118 GeePibber project

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Asgard shared another project the GeePibber, an IEEE-488 (GPIB / HPIB) to USB adapter in the project log forum:

This project is an IEEE-488 (GPIB / HPIB) to USB adapter. I need this because I recently acquired an ancient (but so am I) logic analyzer/oscilloscope which uses only the GPIB to read out and load the instrument’s current state (including state inverse assemblers).

CERN supports KiCad development

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Javier Serrano of CERN’s BE-CO-HT section has sent this message to the Developers list to help enhance Kicad: Introducing CERN BE-CO-HT

As you know, the BE-CO-HT section at CERN has been contributing to Kicad for some time now. We see this involvement as a key part of our activities regarding Open Source Hardware. We are also contributing to the
adoption of VHDL and SystemVerilog in the Icarus Verilog simulator, so as to enable cross-language simulation. Other related activities include the operation on the Open Hardware Repository and the development of the
CERN Open Hardware Licence

Free PCB coupon via Facebook to 2 random commenters

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Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday.

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

Continue reading “Free PCB coupon via Facebook to 2 random commenters”

Week in (p)review April 12, 2013

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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

Soup dumplings in Dongmen market Shenzhen

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If I come back from China 10 kilos heavier this is the man to blame. Some of the best soup dumplings ever. Proper procedure is to bite the top and drink the soup inside. Then eat the pastry and meat filling. Failure to drink the soup results in seriously sticky fingers. 5 dumplings for 10rmb ($1.30). Could not convey face frame so he did peace.

HITB Amsterdam 2013: Aircraft RF hacking

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At the recently concluded HackInTheBox 2013 (HITB) conference German security consultant Hugo Teso has once again drawn into question the security of aero comms. In a presentation at the Amsterdam conference, Hugo highlighted the security vulnerabilities of the Automatic Dependent Surveillance-Broadcast (ADS-B) and Aeronautical Communications Addressing and Reporting System (ACARS) digital aero radio data systems. Net-Security reports, “By taking advantage of these two new technologies for the discovery, information gathering and exploitation phases of the attack, and by creating an exploit framework (SIMON) and an Android app (PlaneSploit) that delivers attack messages to the airplanes’ Flight Management Systems (computer unit + control display unit), he demonstrated the terrifying ability to take complete control of aircrafts by making virtual planes “dance to his tune.” ”

While the presentation video has not been posted yet, here’s a link to the slides. Hugo has also posted a link to his primer on the RF systems discussed in the presentation. (We promise to post the video as soon as it’s released.)

It should be noted that the United States FAA has denied the viability of this hack in an interview with the The Daily Caller.

Via Net-Security.org.

P01-112 Powah project

P01-112C_Powah1_Photo1_Top  P01-112C_Powah1_Photo2_Bottom

Asgard posted his Powah, a little power on/off toggle with an indicator LED in the project log forum:

This is a “standard” module I use for some of my other projects (see the BLiVIT thread). This version is a simple CMOS-level on/off toggle with debounce. The optional four pin positions just happen to lay out so the Powah can be plugged into a breadboard or “hack” area of another board (0.400 x 0.400 inch). I currently am planning to make this available in my Tindie store. Included here are top and bottom photos, plus a schematic.

ULTI-ISP USB programmer for AVR & 8051

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Umair Mukati wrote in to show off his project the ULTI-ISP USB key programmer which supports programming for AVR & 8051 microcontrollers:

The ULTI-ISP can be used to program a wide range of AVR microcontrollers as well as 8051 series. The device can be used to read, write and erase flash memory, EEPROM, Fuse Bits. The product has two programming speed modes. It can be self-programmed by any other AVR Programmer or by another ULTI-ISP using 6pin IDC Cable. Another external header can be used to supply power to the target device.
The ULTI-ISP includes an on-board AVR ATMega8 which deals with all the USB transactions and provides the data to the target device needed to program it. A standard 6 pin IDC ISP cable can be used to program the target device. The two indicators are used to reflect the ULTI-ISP status, one is for power and another is for programming status.

Via the contact form.

Shmoocon 2013: Sniffing Bluetooth low energy


In this presentation from the recent Shmoocon 2013 conference in Washington, DC, Mike Ryan from iSec Partners discusses the new generation of wireless hacking tools to intercept and inject Bluetooth Low Energy (BTLE) communications. Also known as Bluetooth Smart, BTLE was defined in the BT 4.0 spec and will be appearing in a growing number of sports sensors, medical devices, etc.

This talk covers both the Bluetooth LE protocol and the tools and techniques used to study it, as well as live demos of sniffing BTLE using Ubertooth and other hardware.

For links to slides of this and other Bluetooth related presentations visit Mike Ryan’s webpage.

DSETA board, a CPU based on the Atmel AT89C51RE2

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Jechavarria has designed and built this DSETA board, a CPU based on the Atmel AT89C51RE2:

In my last projects, I always use the same CPU. DSETA board, I say in the posts. Well, here it is, a CPU based on the AT89C51RE2 microcontroller from Atmel. I develop this board for some reasons. The first and main one is because I want to have a small board with a great (an known) 8-bit microcontroller, ready to use and with many of the peripherals I usually use. The other reason is that I want to test the PCB service from Seeedstudio, a PCB manufacturer from Shenzhen, China.

Via the forum.

The 3D printer controller

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Matthew of Electronics for Humans has been working on 3D printer controller:

The design is based on an Atmel Atmega328 running at 8MHz (using the internal clock) at 3.3V. This is in order to keep the same voltage as the main controller board, which will be powered by the LPC1768 that only works at 3.3V or thereabouts. Furthermore, I am intending to use the Arduino Bootloader (at least at first) and the Arduino platform in general to program it. The reasons for this choice will be explained later.

Via the contact form.