PC SOUND-CARD SCOPE INTERFACE FACILITATES DC RESTORATION Waveform before correction The 555 Timer IC when operated as an astable oscillator from 5V provides a square wave of 0-5V and the waveform at the timing capacitor varies from 1/3 to 2/3 of 5V. The first screen shot shows the timer IC 555 AC coupled waveforms as captured by the PC sound-card. It can be seen that the zero settles at the average value. (The input has been scaled by 1:10 to remain within the input voltage limits.) Touch Control Panel Small 4-wire resistive touchscreens are now amazingly cheap: they are produced in such enormous quantities for mobile phones, PDAs, and particularly handheld games such as the Nintendo DS that they can be bought brand new for under US$10. Larger touchscreens are also rapidly falling in price. The popularity of netbooks with screens between 7" and 10" in size has resulted in a healthy market for touchscreens that can be retrofitted to them and plugged into an internal USB port. Despite the fact that they come with control electronics and a USB interface those screens are also predominantly 4-wire resistive devices, so if you dump the control module that comes with them and interface to the screen directly you can have a 10" touchscreen on your Arduino! And if you want to go even bigger there are often 15", 17", and 19" touchscreen kits available on eBay for under US$150.
Reflow Skillet Skill Level: Beginner by Nate | July 01, 2006 | 47 comments I've been reflowing SMD parts on PCBs for around a year now. Visual Analyser details Detailed Features about: VA main form (version 8.x.x) (1) - Oscilloscope Dual channel Bandwith : depends from your soundcard (typical 20 Khz) up to 96 Khz (192 Khz sampling frequency) Resolution from 8 bit (S/N 46 dB) up to 24 bit (S/N >120 dB) Time division adjust according the sampling frequency and sample resolution Trigger (positive/negative slope) independent for both channels Complete software D/A of digital samples : the Nyquist theorem allows reconstructing exactly the input signal Utilities for quick frequency determination (hold left mouse button down and move mouse to get frequency/amplitude) Y-axis in Volt and percent full scale Auto calibration of scope (and spectrum) in volts (need an input signal of known amplitude) (2) - Spectrum Analyzer Dual channel Bandwidth : same as point (1) (oscilloscope function): is the half of the sampling frequency.
Charlieplexing Charlieplexing is a technique proposed in early 1995 by Charlie Allen at Maxim Integrated for driving a multiplexed display in which relatively few I/O pins on a microcontroller are used to drive an array of LEDs. The method uses the tri-state logic capabilities of microcontrollers in order to gain efficiency over traditional multiplexing. Although it is more efficient in its use of I/O, there are issues that cause it to be more complicated to design and render it impractical for larger displays. These issues include duty cycle, current requirements and the forward voltages of the LEDs. A Charlieplexed digital clock which controls 90 LEDs with 10 pins of a PIC16C54 microcontroller.
Utilizar el pc como osciloscopio Con este sencillo tutorial construiremos una entrada al ordenador para ser utilizado como osciloscopio. Transformaremos nuestro pc en un osciloscopio. El osciloscopio es quizás el instrumento de medida más deseado por todo aficionado/a a la electrónica. Más deseado, porque es un instrumento caro y no todo aficionado se puede permitir ese gasto. Sin embargo podemos convertir nuestro ordenador en un osciloscopio "casero" con prestaciones aceptables. Lo que vamos a hacer es utilizar la tarjeta de sonido de nuestro ordenador como entrada, y un software especial para mostrar las señales que apliquemos a esa entrada.
Arduino UNO Tutorial 6 - Rotary Encoder Arduino UNO Tutorial 6 - Rotary Encoder We have written a tutorial for Rotary Encoders using a Microchip microcontroller but now would be a good time to make an Arduino UNO version. With a rotary encoder we have two square wave outputs (A and B) which are 90 degrees out of phase with each other. The number of pulses or steps generated per complete turn varies. The Sparkfun Rotary Encoder has 12 steps but others may have more or less. The diagram below shows how the phases A and B relate to each other when the encoder is turned clockwise or counter clockwise. High-Power Control: Arduino + N-Channel MOSFET Eventually you are going to find yourself holding a 12v solenoid, motor, or light and wondering “How the heck am I supposed to control this from my Arduino?” And we have covered this in the past. Today we are going to talk about another way of doing just that, this time with an N-Channel MOSFET metal–oxide–semiconductor field-effect transistor, specifically the RFP30N06LE MOSFET (You can pick these up from sparkfun). but you can use any N-Channel MOSFET exactly the same way. How this works WARNING: I am about to simplify the crud out of this, so beware… it is here in an attempt to explain, in simple terms, what is going on. First off, a MOSFET is a transistor, just a special kind.
"Netduino - Getting Started with *" Series The final Hardware Friday post of the year can't just be on one project now can it? Let's get ourselves set for another great year and get set to hit the ground running building some fun Netduino projects with a great set of Getting Started series by Jeroen Swart Netduino - Getting Started with LCD If you want to show more output then blinking LED’s, an LCD module is a good and usually affordable option. They come in different sizes, from 2 numeric-only digits to 40x4 alphanumeric dot-matrix modules. You can also get graphic LCD’s, that range from modules with small resolutions (e.g. 122x32 or 240x128 pixels) to more professional LCD screens (e.g. 5” or 7”), but I will stick with alphanumeric LCD’s for this post.