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21 Feb 2013


This (SPI7SEGDISP4.40-1R) is a revised version of the previous SPI seven segment LED display (4 digit) board that displayed numerals and decimal points. The new version has a better quality seven segment LED display (LTC-4727JS) with three extra LED segments, as shown below. The additional colon segments are useful in projects where you need to display time (HH:MM or MM:SS).

New version of MAX7219 based 4-digit serial seven segment LED display - [Link]

16 Feb 2013


Giorgos @ PCBheaven build a MCP1640 boost converter for the next LED light project. This converter can be used with almost dead batteries and will squeeze any remaining energy from them. [via]

What i want now, is something to spice up this hack. So here is what – I used the MCP1640 boost converter to drain the last electron from the batteries. This chip can work with a ridiculous low voltage and provide enough power to drive a couple LEDs. Which means the 2 AA batteries will operate even longer and the LEDs will be much brighter.

High efficiency battery boost regulator using the MCP1640 - [Link]

8 Feb 2013


Macroblock MBI5030, 16-ch constant current LED driver with PWM, SPI-like interface, requires external e clock.

The problem: you need the chip to figure out if your code actually works. And you also need the LEDs to see what’s going on – if at all. You could use a logic analyzer, but that is overkill. Just looking at the LEDs is a much more suitable way. Your code might have insidious bugs, or the datasheet might simply be crap / outdated / obsolete – of course without your knowledge. BUT you surely don’t want to fight wires, at least not during the coding / debugging phase. All you need is the chip + onboard LEDs as indicators.

MBI5030 – 16ch LED constant current LED driver starter board - [Link]

6 Feb 2013


Marian Stofka writes:

Battery-operated equipment often will benefit from a power-on indicator. The indicator, however, can waste significant power. In situations where a low-duty-cycle blinking indicator provides an adequate indication of the power being turned on, the simple circuit described here should prove useful.

Low-duty-cycle LED flasher keeps power draw at 4 mW - [Link]

3 Feb 2013


Here’s a tutorial on interfacing MAX7219 LED driver chip to Netduino platform for driving 8 digits of seven segment LED displays. The .NET Micro FramWork provides a SPI class that is used to send display data to the MAX7219 chip through a SPI serial interface.

Netduino and MAX721 interfacing for driving seven segment LED displays - [Link]

29 Jan 2013


Ronald Willem Besinga writes:

One of the basic usage of the TIMER peripheral on every microcontroller is to provide the accurate timing mechanism. Using the TIMER peripheral as the basic timing, we could easily develop a stopwatch and display it to the 8-Digit seven segment numeric LED display. Thanks to the Maxim MAX7219 chip which enable us to interface this 8-Digit seven segment LED display much easier using just three wires of the SPI (serial peripheral interface) to display the hour, minute, second, and hundredth of seconds to the 8-Digit seven segments LED display.

Build your own stopwatch using Maxim MAX7219 Serially Interfaced, 8-Digit LED Display Drivers - [Link]

25 Jan 2013

285656-LED_flashlight_circuit_works_at_voltages_as_low_as_0_5V_figure_1GY Xu writes:

Most commercial LED flashlights use three AAA or AA batteries in series that produce 4.5V. The batteries then drive four white LEDs that connect in parallel. These LEDs can work at voltages as low as 2.7V and, in some cases, 2.4V. At those voltages, the LEDs become dim, and you must frequently change the batteries. Thus, the lowest working voltage in this case is approximately 0.8 to 0.9V per battery.

When a 1.5V alkaline battery discharges to 0.9V, it still has more than 10% of its original energy left. If you replace or discard the battery, you waste that energy.

LED-flashlight circuit works at voltages as low as 0.5V - [Link]

12 Jan 2013


New aluminium profiles in our portfolio will help you to apply LED strips or other linear LED light sources.

LED strips or PCBs with LEDs are in fact only a semi/product, which should be in the most of cases mounted into an appropriate profile. Two new aluminium profiles are excellently suitable for this purpose, with the possibility to buy a transparent or semi/transparent plastic cover.

Advantages / Features:

  1. ideal for LED srips and mid-power LEDs
  2. suitable for panels and for furniture
  3. usage without or with embedding
  4. 1m long
  5. aesthetic and safe solution

● Profile ZH-9099/1000 is suitable to be embedded into panels, furniture and similar.

● Profile ZH-9460/1000 is ideal for installation without embedding – on a surface. That´s why it features somewhat higher cooling properties.

Both types are anodized (natural elox) and they can be equipped with termination profiles and transparent plastic covers. Transparent cover transmits almost 100% of light, thus almost not affecting the luminous flux from LEDs. Semi-transparent cover transmits 75% of light and provides a soft diffused light.  In case of interest in these heatsinks, high-power LEDs or LED strips, please contact us at  info@soselectronic.com.

Comfortable and safe installation of LED strips with new profiles – [Link]

30 Dec 2012


Embedded Lab has posted a new project of constructing an 8-digit seven segment LED display board with a serial interface. Seven segment LEDs are very bright and attractive display devices. However their use in microcontroller projects is sometime limited by lack of I/O resources. The use of MAX7219 allows you to add 8 digits (more if cascaded) of seven segment LED displays using only 3 I/O pins of the microcontroller, and provides full control of all the digit segments and decimal points.


MAX7219 device can be easily interfaced to Arduino using LedControl library. The library also supports cascading of multiple MAX7219 devices.

The serial 8-digit seven segment LED display kit is also available for purchase on Tindie.

Serial (SPI) 8-digit seven segment LED display kit - [Link]

25 Dec 2012


by Steven Keeping:

High-brightness LEDs tend not to burn out rapidly. Rather, they slowly fade away. A carefully designed LED lighting system can see the light source last for up to 50,000 or even 70,000 hours before the illumination is no longer sufficient for the intended job.

What causes the chip to lose luminosity, and can anything be done to arrest the decline? This article reviews the physics behind an LED’s photon generation to explore what happens when the device is new, and then why the performance inevitably deteriorates as the chip ages.

Understanding the Cause of Fading in High-Brightness LEDs - [Link]





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