Author Archives: Arup

App Note: Adjustable power supply using a digital potentiometer

How to use a digital potentiometer to calibrate and control an adjustable power supply. A resistive feedback network is often used to set the output voltage of a power supply, since fixed resistors are simple to use and low cost. However, because a fixed network is not adjustable, the output voltage cannot be accurately set. […]

Simplecortex ARM Cortex M3 dev board

Riktw designed, and got ITead Studio to produce, a Cortex M3 based Arduino compatible board called Simplecortex. The board uses the LPC1769 microcontroller from NXP: The Simplecortex is a microcontroller development board that is shield compatible with the Arduino. The Simplecortex has a fast microcontroller, the LPC1769 from NXP. This is a ARM Cortex M3 […]

LED produces 2.3x more light energy than electrical energy consumed

MIT physicists developed an LED that emits more light energy than the electrical energy consumed. These LEDs supplement electrical energy with heat from the surrounding environment. Unfortunately this has only been observed at very low power levels. The researchers chose a light-emitting diode with a small band gap, and applied such small voltages that it […]

Squeeze the power out of batteries using AASaver

Are you looking for a portable breadboard power supply with a selectable voltage? Also thinking about how long the batteries will last? This project utilizes one or two AA/AAA batteries to generate a preselected voltage of 5V or 3.3V, and  squeezes the batteries untill they have almost no power at all.  AASaver is based on […]

TI’s Wolverine is an even lower power MSP430

Texas Instruments claims to have concocted an even lower power MSP430. The MSP430 Wolverine series uCs consume 100uA per MHz when active, and 360nA in standby. TI claim this is 50% less power consumption than any other micro. You can download the whitepaper and check out all the specs. Tasty samples available around June 2012. […]

App note: Soft-Start in LED lighting

Using constant current to drive LEDs is a good practice, but turning them on instantly can be dangerous for both the LED and the LED driver.  Harmful spikes are generated when large currents are instantaneously turned on. This app note from Maxim describes how to soft start LEDs to increase overall lifetime and performance. An […]

DIY double sided PCB with soldermask

Retromaster has honed his PCB making skills to get professional quality boards at home. He’s successfully made double sided PCBs with 8 mil trace width, with 6 mil clearance. In his guide he describes how to etch the PCB with toner transfer, how to use mechanical vias, and hot to apply soldermask paint.

PSoC3 system on chip dev-board: SSOP IC soldered

Kartik soldered the first prototype of his PSoC3 development board. He used a no-solder soldering technique to solder the SSOP IC.  He had great success with this technique, after destroying a few PCBs with his old method. Things didnt go that well on the first board I tried out,mainly due to me using the wrong […]

App note: Enhancing ADC resolution by oversampling

Better ADC resolution can be accomplished by oversampling two or more ADC readings and then averaging them. If you’re not satisfied with a microcontroller’s 10 bit ADC and need more resolution, check out this application note from Atmel. Increasing the ADC resolution by one bit requires 4 ADC measurements.  Four 10 bit readings are needed […]

DIY PIC16F883 breakout board

Phil made a DIY breakout board for the PIC16F883 microcontroller. The board uses a surface-mount single-layer design, and the parts are nicely spaced.  It’s an easy board to make at home using the DIY toner-transfer method of PCB etching. You can download the source files and other design data from his site. Via Jumperone.

FTDI FT232 USB to serial converter chips for $2.50

While browsing suppliers for FTDI chips at cheap singles prices, this offer caught our eye. Dontronics is selling FTDI FT232RQ for just AUD$2.45, which is near $2.50 USD. In many projects a USB to TTL converter chip is needed, and FTDI chips are the most common solution around. Both Digikey and Mouser sell the FT232R […]

7400 competition entry: Hex KeyPad

Adam submitted his Open 7400 Logic competition entry, a 16 button keypad that outputs the hexadecimal value in a 4 bit binary equivalent. Adam wrote This is a handy device for prototyping, etc… It’s a hexadecimal keypad (0..9, A..F) that outputs the hexadecimal value on 4 digital binary lines (one nibble). It has both active […]