Welcome to Provide Your Own - electronics


Choosing PCB Layout Software

pcb

When you finish the design and prototyping of your project and you want to make a PCB, you need to use some kind of PCB layout software. While there are a plethora of commercial products, most of them expensive – very expensive, there are relatively few that are low cost or free for the open source designer. This guide will look at the options available and make recommendations based on the author’s knowledge and preferences.

NOTE: There may be some other applications than the ones I have mentioned. Since I use Linux on my PC, I have only looked at the packages than run under Linux. I believe the ones listed run under all three mainstream operating systems, but I am only certain about Linux versions.

Online PCB Software

Some commercial PCB fabricators offer their own free online software. While some of these products may be quite capable, they suffer from one huge drawback – you are locked into their services. If you want to have your PCB made elsewhere, you are out of luck. For that reason I don’t give these programs a second look.

Eagle CAD

screen shot of Eagle CADThe Eagle CAD package offers both schematic and PCB layout programs. It … Read the rest

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Make Your Own Solder Flux

diy_flux

I found this great video on making your own flux for soldering. Flux is a must have product when doing any electronics work, especially for surface mount parts. It helps to clean dirty parts and improves the surface tension of the molten solder so it stays on the pads instead of running between them (called bridging).

One would think that making your own solder flux wouldn’t be as good as the real thing. That may be true in some cases, but for most this at-home method is not only inexpensive but allows you to vary the thickness of the flux. Commercial flux comes in viscosities ranging from a watery liquid to a waxy paste. To understand how to create your own viscosity, let’s look at the recipe:

  • Isopropyl alcohol – the kind in your medicine cabinet
  • Pine Rosin – thickened sap from trees. Used to make violin bow hairs grab the strings and make them sing. Search for violin rosin on e-bay, and buy for a few bucks.
  • Glycerin – just a drop or two per batch (2-3%). Buy in drugstores.

To make a batch, simply crush the rosin into a powder with a hammer (put into an envelope first … Read the rest

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Guide to Arduino and AVR Communications

easytransfer_serial_arduino_communications_library

If you spend any time playing with Arduinos, ATtinys or looking at AVR spec sheets, you soon encounter a bewildering smörgåsbord of acronyms for various communication protocols. With examples such as I2C, LIN, SPI, TWI, USI, etc., it can get pretty confusing. If you don’t believe me, just take a look communications column for Digikey’s listing for the ATmega series chips. Confused yet?

What do these terms mean? How do you choose the chip that meets your needs? How do you make use of these protocols?  In this article, I take the mystery out of all these acronyms, and provide a brief overview of what they mean and how you use them in your projects. We’ll examine each of the protocols, including some of the terms that are not exactly protocols, and survey some of the software libraries available to make communications easier.

Communication Protocols

SPI

The SPI (Serial Peripheral Interface) is the protocol used by the ICSP (in-circuit serial programming) facility transmitted over the ubiquitous 6-pin (2×3 pin) header used to program AVR chips. It is useful not only for programming AVR chips, but also for other types of communications between ICs. From Wikipedia:

SPI interface diagram

The Serial Peripheral Interface

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Make Your Own PCB
  1. Making Your Own Printed Circuit Board - An Overview, part 1
  2. Making Your Own Printed Circuit Board - An Overview, part 2

Making Your Own Printed Circuit Board – An Overview, part 2

In the first part of this article, we covered the extensive subject of imaging a design onto a blank board and the best way to etch that board. After completing these steps, you will have a PCB almost ready for assembly. I will now explain the remaining steps. Some are essential and some not so much. As usual, each has their own set of problems to overcome.

Drilling

Now that you have a nice shiny PCB with your traces and pads imprinted on it, you need to drill the holes for thru-hole components and vias. The easiest way to do this is with a desktop drill press. Since I don’t have a dedicated PCB fabrication setup, I found another easy method for drilling holes at home. Harbor freight sells a 12v powered Dremel-type tool. While this tool is way under-powered for most tasks, it turns out to be a virtue when drilling small PCB holes. I simply chuck up a #60 bit and the hole already etched in the copper pad provides a nice indentation to hold the bit steady. The low power prevents the drill from getting squirrelly and jumping out of the indentation. You can probably get similar results with … Read the rest

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Make Your Own PCB
  1. Making Your Own Printed Circuit Board - An Overview, part 1
  2. Making Your Own Printed Circuit Board - An Overview, part 2

Making Your Own Printed Circuit Board – An Overview, part 1

PCB Image Transfer

If you start tinkering with electronics, eventually you will want to make your own printed circuit board, or PCB as it is generally called. In the olden days, this subject was pretty straightforward. You went down to your local RadioShack, and bought an etching kit. You drew your single sided design using a marking pen and some supplied stickers. The board was fairly big, and it had only a few simple through-hole components.

Those days are now pretty much gone. Now most electronic projects are much more complex, the boards are much smaller, and you need to deal with 2 layers, surface mount components and vias. In this overview, I will tackle the different problems you may encounter and the methods available. I won’t cover PCB layout software or commercially made boards. I’ll deal with those topics in separate articles.

Basic Steps

Making a PCB involves several steps. Today’s PCBs require a lot more steps than they used to, but for your own use, these later amenities can be omitted. The steps involved are:

  1. Imaging your design onto a blank PCB
  2. Etching
  3. Drilling
  4. Amenities – solder mask, silk screen, tin plating
  5. Vias
Each of the steps can be fairly involved and each … Read the rest
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Program an ATtiny Using an Arduino

Arduino

I am a big fan of the Arduino platform. For those who aren’t familiar with the Arduino, it is a microprocessor development environment & ecosystem. You can visit their site for more info. I started playing with the Arduino and soon discovered the ATtiny microprocessor chip, which is a much smaller cousin to the ATmega series which is used in the Arduino.  Unfortunately, the Arduino IDE did not support it. Since most micro development apps run only on Windows (I use Ubuntu Linux), and require either expensive compilers or hard to use C or Assembler, I was never up to the effort required in using the ATtiny chips.

All of this changed yesterday when I was going through my Arduino notes and came across some attempts by others to use the Arduino IDE to program the ATtiny. One fellow was successful on the ATtiny45. Another tried on the ATtiny85 but didn’t seem to get as far. After much searching, I stumbled across the Arduino-Tiny project. The project is fairly mature, and they have already done all the hard work. The result is fantastic. You can program in C++ using the regular Arduino libraries (which have been modified for the … Read the rest

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