How you can make perfect PCBs yourself

diodenring.de writes:

I am using a positive photo-lithographic process to transfer the artwork to a photosensitized, copper cladded PCB laminate. Positive means, that during the development step the protective coating on the copper is removed in those places that were previously exposed to UV light. So the artwork has to block UV light where you want the traces on the board.

How you can make perfect PCBs yourself – [Link]

Intervall Timer for Nikon and Canon DSLR

Features:

  • No power supply needed: The circuit “steals” in the operating current (only 10µA at 5V and 2.5µA at 3.3V) from the signal lines of the camera
  • Interval adjustable from 0.4 seconds to about 18 minutes
  • No controls, setting of the intervall via “teach-in” from the camera
  • Ultra-portable: the circuitry fits into the housing of a 2.5mm stereo plug
  • Component cost: 87 ct (July 2010)

Intervall Timer for Nikon and Canon DSLR – [Link]

RELATED POSTS

Dead Bug Prototype Soldering

Dave show you how to solder a small 3 axis accelerometer LGA surface mount chip “dead bug” style onto a microcontroller prototyping board. This technique allows you to easily prototype projects using tiny SMD components designed only for reflow soldering.

Dead Bug Prototype Soldering – [Link]

The backcountry logger

Big Mess o’ Wires backcountry logger: [via]

If you’re just tuning in, the backcountry logger concept is a portable ATmega-powered device that collects temperature, air pressure, and altitude data, and shows graphs on a built-in LCD screen. It’s intended for hikers, climbers, and other outdoorsy folks who want to know if it was colder last night than three nights ago, whether the ridge they’re on is the 10200′ or 10600′ one from the map, or whether a storm is likely soon. Much attention has been giving to minimizing power consumption, so the battery should last many months.

The backcountry logger – [Link]

Amateur radio study guide has much information about electronics

Ham radio is nothing new, however if your new to electronics, or interested in becoming a ham, we suggest reading one of Dan’s self-study guides. [via]

The RMS value of an AC signal is the voltage that causes the same power dissipation as
a DC voltage of the same value. (G5B07) For an AC signal with a sine-wave shape, the
RMS value is .707 times the peak value. 12 volts is the RMS voltage of a sine wave with
a value of 17 volts peak. (G5B09)

Conversely, the peak-to-peak value of an AC signal is 2 × 1.414 × the RMS value.
Accordingly, 339.4 volts is the peak-to-peak voltage of a sine wave that has an RMS
voltage of 120 volts. (G5B08)

Power is equal to the RMS voltage times the current, or
P (watts) = VRMS x I

Using Ohm’s Law, we can show that:
P = V2RMS / R
P = I2 x R

Amateur radio study guide has much information about electronics – [Link]

Hot Air Tool

Soldering irons are the primary tool used for soldering, and we use ours all the time for soldering. But for leadless parts, like QFNs, or ultra-tiny components that need rework, hot air can be superior! [via]

Hot Air Tool – [Link]

Working with Atmel AVR Microcontroller Basic Pulse Width Modulation (PWM) Peripheral

ermicro.com writes:

Pulse Width Modulation (PWM) is a technique widely used in modern switching circuit to control the amount of power given to the electrical device. This method simply switches ON and OFF the power supplied to the electrical device rapidly. The average amount of energy received by the electrical device is corresponding to the ON and OFF period (duty cycle); therefore by varying the ON period i.e. longer or shorter, we could easily control the amount of energy received by the electrical device. The Light Emitting Diode (LED) will respond to this pulse by dimming or brighten its light while the electrical motor will respond to this pulse by turning its rotor slow or fast.

Working with Atmel AVR Microcontroller Basic Pulse Width Modulation (PWM) Peripheral – [Link]

The LM324 Quad Op-Amp Line Follower Robot with Pulse Width Modulation

ermicro.com writes:

Designing a simple and yet functional Line Follower Robot (LFR) is always a fascinating and challenging subject to be learned, the LFR actually could be implemented in many ways start from a simple two transistors to a sophisticated PID (Proportional, Integrate and Differential) which take advantage of the programmable feature of microcontroller to calculate the PID equation to successfully navigate the black track line on a white background surface.

The LM324 Quad Op-Amp Line Follower Robot with Pulse Width Modulation – [Link]

 

Using Serial Peripheral Interface (SPI) with Microchip PIC18 Families Microcontroller

ermicro.com writes:

The Serial Peripheral Interface (SPI) is one of the popular embedded serial communications widely supported by many of today’s chip manufacture and it considered as one of the fastest serial data transfer interface for the embedded system. Because of its special in/out register configuration, the SPI master device could transfer its data and at the same time it receive a data from the SPI slave device with the clock speed as high as 10 MHz. Beside its superior data transfer speed; SPI also use a very simple data transfer protocol compared to the other serial data transfer methods. When the SPI master device want to send the data to the SPI slave device then the SPI master will just simply shifting its own data through a special 8-bits register and at the same time the SPI master will receive the data from the SPI slave into the same register as shown on this following picture:

Using Serial Peripheral Interface (SPI) with Microchip PIC18 Families Microcontroller – [Link]