Archive for September 2011

Hand Soldering Fine Pitch LGA Chip

Many of the modern chips such as MEMS accelerometers and gyroscopes only come in surface mount versions and many of them come in fine pitch LGA or QFN packaging. This has created a significant challenge for people who just wanted to experiment with these components. The standard soldering technique for LGA/QFN chips is reflow soldering which requires special equipment such as reflow oven and hot air rework station. Special surface mount prototyping PCBs are also needed and these PCBs, depending on the size and complexity can be quite expensive and sometimes are pricier than the components themselves. Continue reading ‘Hand Soldering Fine Pitch LGA Chip’ »

A Unipolar Stepper Motor Driver

The drive circuits for Unipolar stepper motors are usually very simple. In its simplest form, a transistor or MOSFET is used to drive each section of the windings. With this design, the control signal must be supplied programmatically to the four windings of the unipolar stepper motor via an MCU. Continue reading ‘A Unipolar Stepper Motor Driver’ »

My Take On BK 2709B Multimeter

I recently bought a new digital multimeter (BK 2709B) and after a couple of months’ use, I am quite satisfied with its features and performance. So I thought I would do a quick review and share my experience here. Continue reading ‘My Take On BK 2709B Multimeter’ »

Interfacing DS28EC20 with Arduino

DS28EC20 is a 20Kb 1-Wire EEPROM chip from Maxim. Like all other 1-wire devices, only a single pin is needed for both power and communication. In this blog posting, I will show you how to how to communicate with DS28EC20 using the popular Arduino platform. Continue reading ‘Interfacing DS28EC20 with Arduino’ »