These two chips provide an easy way to control either an array of 64 Led’s or up to eight digits made of 7-segment displays with a minimum of electronic components. Besides the chip itself you will need only a single resistor and one or two capacitors. Data is send to the chip using a SPI-compatible […]
For my project, the Arduino output is not enough so digging on the net and asking to a friend some help, I managed to build an amplifier to feed my 3 computer fans. This circuit can be used as an amplifier to switch on and off a DC motor and to regulate its spinning speed […]
Oscar Gonzalez gives us a simple tutorial for speed controlling a PC FAN and reading a LM35 temperature sensor with an Arduino microcontroller. He covers the use of an optocoupler, PWM (Pulse Width Modulation) and reading analog voltages with the Arduino. He even has a video showing the fan speed control in action. This article […]
Part 1. Analog Front-End. Opto-Isolator. Looking at the Power Quality Analyzer display, I was wandering, if there is any error in the measurement results, introduced by transformer. Overall THD picture doesn’t change much, suspiciously drawing same chart in the morning and in the evening, when electrical grid load significantly differs. Obviously, to estimate effect of […]
Biasing AC input using resistor divider and scaling up / down if necessary; Sampling fast and accurately using direct access to Control Registers of ADC and Timer1; Subtract whatever was added at step #1 from result of Analog / Digital conversion and Square; Average / accumulate, filtering following VU specification; Sqrt – take square root, […]
ow my Arduino can precisely measure audio input (VU meter), and obviously, next thing that comes to mind right after measurements, is regulation or control. There are many different ways how to electronically adjust audio volume or level of AC signal. I’ll name a few: Specifically design IC, Digital potentiometers. Mechanical potentiometers, driven by servo […]
Well, it’s elementary simple in theory, how to do sound localization based on phase difference of signals, that received by two spatially distant microphones. The Devil, as always, in details. I’ve not seen any such project created for arduino, and get curious if it’s possible at all. Long story short, here I’d like to present my […]
Synthesized speech was for a long time the Holy Grail of computing, and back in the 1980s when a 4MHz CPU made your computer the fastest machine in the neighborhood it just wasn’t practical for software to create intelligible speech. In those days the only sensible way to generate speech was to offload the task […]
The basic idea was to create color organ / spectrum analyzer on arduino board, trying to minimize quantity of external components, like analog filters, LED display drivers, etc. Spend a lot of time in search on internet I was able to find only two ! project , which implemented FFT in order to solve a […]
I’ve just completed my second Arduino project, a sound level detector which sets off an “alarm” when there’s the sound level is to high for too long. I built it for use in a school that wants to provide visual feedback to students when they are being too loud. The “alarm” is a string of […]
