Posts tagged ‘AVR’
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’ »
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’ »
Modified sine wave is essentially just a pulse width modified square wave. It is a very useful waveform for power inverters. Compared with the simplest inverters with square waveform, inverters using modified sine wave can compensate the output voltage by simply changing the pulse width (duty cycle) of the waveform. Continue reading ‘Modified Sine Wave Generation With AVR’ »
I have been thinking about building an LC meter for a while since I do not have a multimeter that is capable of measuring inductance and while the multimeters I have can measure capacitance, they are not able to give accurate readings for small capacitance in the range of several pF’s. Continue reading ‘AVR LC Meter With Frequency Measurement’ »
ATmega328p does not provide any Digital/Analog conversion channels (although the D/A conversion can be simulated by means of measuring the PWM output). We can easily add up to eight D/A channels using either a LTC1665 (8 bit) or LTC1660 (10 bit) from Linear Technology. Continue reading ‘A Library for LTC1665/LTC1660’ »
In my last post, I described in detail how to hand solder LIS3LV02DL, an LGA packaged accelerometer chip. And here I will show you how the communication with Arduino is done using SPI. Continue reading ‘Interfacing LIS3LV02DL Using SPI — II’ »
I was inspired by Paul’s 7 segment display and decided to build one myself. He used 4 common cathode 7 segment displays. In his original schematics, all the segments within a display shared one current limiting resistor which unfortunately affect the display brightness when different numbers of segments are lit. I happened to have two common anode dual 7 segment displays (QDSP-G545) so I decided to use them and four 74HC595 shift registers to build a four 7-seg display. Realizing that other people might be using either common anode or common cathode displays, I also built a library that can be used for either case. Continue reading ‘4 Digit 7 Segment Display Using Arduino’ »
I have been using the FTDI bitbang method piloted by Kimio Kosaka and improved by others (1,2,3) to flash Arduino bootloader onto blank ATMega328p for a while and thought I would share my experience with everyone. Continue reading ‘On ATMega328 Bootloading With FTDI Bitbang Method’ »
H-bridge is frequently used to control DC motors and stepper motors. When controlling a bipolar stepper motor, two full H-bridges are needed. There are many H-bridge ICs (like L298, MPC17529 and SN754410 which is a quad half H-bridge) for just that purpose. But if you are on a budget, you may want to consider building a dual H-bridge yourself. Continue reading ‘A Simple Dual H-Bridge’ »
After going through some of the tutorials on Arduino’s site, I really started to appreciate what a powerful platform Arduino really is. A lot of seemingly complex software/hardware interactions can be made quite easy with relatively few components and little coding. As one of my first Arduino based projects, I built a simple power inverter driven by Arduino. Continue reading ‘A Power Inverter with Arduino Pulse Source’ »
When I first started interfacing electronics with computers back in the early 90’s my hardware choice was an ISA AD/DA card. So when I wanted to experiment with some physical computing stuff recently, I thought of getting an AD/DA card that can be plugged into either a PCI or a PCI Express slot. Continue reading ‘Hello Arduino’ »