A light dimmer I replaced includes an orange on/off indicator that makes the dimmer easy to find in the dark. Most likely, the manufacturer used a neon glow lamp rather than an LED in the unit. I found a few old NE-2 glow lamps in one of my parts drawers and it brought back memories of experiments done long ago before my days playing with transistors. You can still buy NE-2 bulbs and the higher-intensity NE-2H variant. I found both at Jameco: Part no. 27351 ($0.45) and Part No. 210315 ($0.29). You can find this type of glow lamp in a T3-1/4 size with a bayonet base.

What's so cool about an old neon indicator lamp? The neon lamp has an interesting characteristic: When you increase the voltage across the lamp it does not turn on--or ionize the low-pressure neon gas--until the power supply reaches a high "strike" voltage. At that voltage, the lamp "fires,&q...Read More

An announcement about a new development kit, this one for programmable logic devices (PLDs), arrived a few days ago. PLDs seem to have faded into the background, so I thought the kit might deserve some attention.

The kit provides some interesting capabilities and its price of about $US 120 puts it within an engineer's discretionary budget, so I looked deeper. The kit supplier offers a variety of tools and several add-ons, one of which requires that users register before they pass "Go" and get the download, or ask for it. Once registered, people can, "...access online technical support, educational webcasts, software downloads & licensing, and simulation files and IP packages."

But, why do I have to "register," and choose yet another user name and password, just to see if this company has information I might use? I understand a...Read More

SchmartBoard manufactures a wide variety of prototyping boards engineers use when they must hardwire a circuit. The latest through-hole board, model number 201-0302-01, measures 4x4 inches (10x10 cm) and offset rows of connected through holes occur on an offset grid cover 75 percent of the board. When I saw a photo of the board, I wondered how a dual-inline package would work on the offset pattern, so Neal Greenberg, SchmartBoard’s VP of sales and marketing sent me a sample so I could see for myself.


The offset rows have a 0.050-inch spacing, as shown in the diagram below. The pattern of four connected through holes repeats across the board. In my diagram, the black dots represent the holes used by a 0.300-inch-wide DIP and the red vertical lines indicate the sides of the DIP. Note...Read More

During the last two months, announcements of new touch sensors and touch-sensor capabilities have arrived from Silicon Labs, Freescale, and Atmel. But the technologies differ and give engineers a variety of capabilities to use in their designs. Here's a quick overview of the technologies and links you can follow for more information. On November 6, 2009, I added new information from Cypress Semi. (Note, this blog entry runs a bit longer than usual.)

Atmel -- maXTouch capacitive touchscreen controller

The mXT224, Atmel's first maXTouch touch-sensor controller and microcontroller IC lets developers place as many as 224 sensing nodes across a 10-inch display screen. People can use a stylus, finger, or even a fingernail to draw, sign their ...Read More

You never know where new chips based on an ARM CPU will pop up. Energy Micro AS of Oslo, Norway has used an ARM Cortex-M3 CPU in its Gecko processor family and just released a new low-power EFM32G microcontroller (MCU). The company's announcement of the new MCU notes the EFM32G consumes less than 180 μA per MHz as it runs real-world code from flash memory. The company claims, "...the MCU achieves the lowest active-mode current consumption of any microcontroller. Its standby current consumption is also the lowest, at typically 900 nA while running real time clock, power-on reset, brown-out detector and full RAM and CPU retention, and less than 20 nA in its deepest sleep mode. Furthermore, the microcontroller’s start-up time of less than 2 μs is the industry’s fastest." Find Energy Micro at www.energymicro.com.

When Texas Instruments acquires Luminary Micro--a vendor of ARM-based microcontrollers--I worried that TI might simply drop Luminary Micro's Stellaris MCUs into some forgettable part-number bin. Thankfully, TI has kept the Stellaris brand and aggressively expanded it. On October 21, 2009, TI announced 29 new Stellaris ARM Cortex-M3 devices that offer pin compatibility with existing Stellaris devices, increased memory, and more communication capabilities. The TI press release noted:

LM3S1000 series: Eight new MCUs with high pin counts, general purpose real-time processing.

LM3S3000 series: Five new MCUs with USB devices, USB Host/Device and USB On-the-Go (OTG) support.

LM3S5000 series: 14 new MCUs with USB devices, USB Host/Device and USB OTG support, along with Bosch 2.0 A/B CAN support.

LM3S9000 series: Two new MCUs with 10/100 Ethernet MAC+PHY...Read More

Tektronix has published a 60-page primer, "XYXs of Oscilloscopes," that explains how a scope acquires and displays information. The booklet also explains the controls users operate to capture and display the signals that most interest them. Even if you consider yourself a scope expert, the primer might provide some new information, and you can always pass it along to colleagues, new engineers, and technicians who lack your scope smarts.

I registered previously on the Tektronix Web site, so it took no time to get to the proper page and download the primer. But if you haven't alreadt registered, you might have to supply some information before you can download the material. Try: www.tektronix-resources.com/0905basicscopes/XYZsOfOscilloscopes.pdf.

Th...Read More

A Gadget Freak project on the Design News magazine Web site used an mbed (yes, it's all lower-case letters) microcontroller module to control one of those Billy Bass singing fish popular as a gag gift about 10 years ago. The mbed module looks like an interesting and simple way to get a quick start with an LPC1768 ARM Cortex-M3 microcontroller from NXP Semiconductors.

The people at mbed have placed the MCU on small circuit board with two rows of 20-pin contacts along each long edge. So, you can drop a module into a solderless breadboard or even into a final product. Just to prove good things do come in small packages, the module-and-chip package provides the 100-MHz Cortex-M3 core with 64 Kbytes of SRAM, and 512 Kbytes of flash memory. I/O devices include Ethernet, USB, SPI, I2C, UART, CAN, GPIO, PWM, a 12-bit ADC and a 10-bit DAC. (The built-in Ethernet por...Read More

Intel's 8086 16-bit microprocessor and its 8-bit sibling, the 8088, gave the personal computer market a tremendous boost when IBM adopted the 8088 in 1981 for the original IBM PC and used 8086-family devices in the later PC-XT. Although Intel introduced the 8086 and 8088 in 1978, it took several years for computer engineers to adopt them in a big way.

(For a history of IBM's PC development, see: www.tmworld.com/article/324805-Whence_came_the_IBM_PC_.php.)

Because Intel already had a big investment in its earlier 8080 8-bit microprocessor and because developers created a lot of software for the 8080 (and for Zilog's almost-compatible Z80), Intel wanted to preserve some backward compatibility. This decision lead to the use of direct addressing of memory within a 16-bit address space. ...Read More