Kerry D. Wong

Since the current Arduino tools do not support in-circuit debugging, you will have to rely heavily on the serial print outs when tracking down those hard-to-find bugs unless you are one of those few elites whose code just works 100% every time. It is all good when you are doing your development when a computer is readily available. But what if you need to capture the outputs when you do not have the access to a computer? I found myself running into this situation quite often. Continue reading ‘Adding Off-Screen Buffer to Serial LCD Display’ »

One of the biggest advantages of FRAM (or FeRAM, Ferroelectric RAM) over EEPROM is that FRAM has a much higher write speed and typically can operate at bus speed. This means that no delay instructions are needed when performing write operations, which greatly reduces coding complexity and increases the overall throughput. Continue reading ‘Using FRAM as Nonvolatile Memory With Arduino’ »

MMA8453Q is a rather inexpensive accelerometer. It is significantly cheaper than many other 3-axis accelerometers (such as the popular LIS3LV02DL) and yet it offers a reasonably high 10 bits resolution and packs a rich set of features that simplifies designs and programming in many different applications. Continue reading ‘Interfacing MMA8453Q With Arduino’ »

A while back, I created an Arduino plugin for NetBeans so that I could use the full-fledged NetBeans IDE for all my Arduino projects. The approach I took was using the NetBeans project sample module method. Under the hood though, it is nothing more than a makefile and an source file template. Continue reading ‘Makefile for Arduino 1.0’ »

I have built quite a few (1,2,3) temperature measurement circuits in the past, but none of those has remote sensing capability. So I decided to make a wireless temperature sensor so that temperature measurements can be made anywhere within the range of the transmitter and the receiver. Continue reading ‘Building a Wireless Temperature Sensor’ »

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’ »

I wanted to be able to check my web server’s statistics periodically but did not want having to log on ever time when I wanted to do so. The simplest way to achieve this is to have the computer monitor on and run a server statistics program that outputs the information onto the screen. Continue reading ‘Building an Auxiliary Display’ »

Most of the recent Arduino and compatible boards use some kind of USB to UART hardware (e.g. FT232RL in Arduino Duemilanove and Atmega8U2 in the latest Arduino Uno) for interfacing with computer USB ports. Since ATmega328 has native UART support, building an Arduino that interfaces with the serial port (RS232) directly is arguably much easier. Continue reading ‘Arduino Serial Using LT1780’ »

As I mentioned a few weeks ago, I was in the process of building tools necessary to bootstrap the hardware needed for PIC development. So far, I have built a simple parallel port programmer and have used it to flash the firmware for the USBPICProg programmer I built later on. Continue reading ‘First Pinguino Build’ »

I built a 4-digit 7 segment display last year. In that design, I used four 74HC595 shift registers to drive the four individual 7 segment displays, with one for each digit. So when I wanted to build an 8-digit display, I thought about using the same design with eight 74HC595s at first. But it seemed that the soldering would be a lot more challenging on the prototype board as there will be 8 chips and 64 resistors to solder. Continue reading ‘An 8-Digit 7 Segment Display’ »

One of my old computers is used as a file backup server in my basement office. It is kept off most of the time and only powered on when I needed to sync up files. Continue reading ‘Wake On … IR’ »

AD7705 and AD7706 are two 16-bit Sigma Delta ADCs. Equipped with on-chip digital filters and programmable gain front ends, these chips are ideal for low frequency multi-channel signal measurements. The main difference between AD7705 and AD7706 is that AD7705 has two fully differential input channels while AD7706 has three pseudo differential input channels. Continue reading ‘AD7705/AD7706 Library’ »

The DS7505 digital thermometer and thermostat is a very versatile temperature sensor. It offers 9 to 12-bit digital temperature readings between -55 and +125 Celsius with an accuracy of 0.5 degree. It can be used with any MCUs that has I2C support or can be pre-programmed and used in standalone applications as digital thermostats. Continue reading ‘Interfacing DS7505’ »

TCA9555 is a 16-bit I2C I/O expander from Taxes Instruments. It allows the easy addition of 16 I/O ports on any device that supports the I2C bus. This makes it attractive for expanding the number of I/O pins on the standard Arduino platform using ATmega328. Up to eight TCA9555′s can be used on the same I2C bus and thus allowing up to an additional 128 digital pins to be added. Continue reading ‘TCA9555 Library for Arduino’ »

Arbitrary waveform generators come in handy when troubleshooting digital and analog circuits. Most commercial arbitrary waveform generators are very expensive due to the functionality and very high bandwidth they offer. But for typical uses among hobbyists, the requirements are generally pretty low. Building a very basic arbitrary waveform generator is actually quite simple using a digital-to-analog converter (DAC) chip and a microcontroller (MCU). Here I will show you one such waveform generator using Linear Technology‘s LTC1450 DAC and ATmega328 programmed with Arduino libraries. Continue reading ‘Arbitrary Waveform Generation with Arduino’ »