Electronics

Breadboard power supply

I am currently trying to document the various electronics I have done previously. A brief page about my breadboard power supply is now available.

Right angle corners for PCB traces

There is a lot of myth and misconception about whether right angle (90°), chamfered (45°) or curved PCB traces are “better”. One of the often quoted “facts” is that right angles are bad for signal propagation or radiated RF emissions. I came across a great paper titled “Time and Frequency Domain Analysis for Right Angle Corners on Printed Circuit Board Traces” (PDF link) by Mark I. Montrose which has in-depth analysis and experiments to test this theory out.

The ST7565 display controller

I have moved the contents of this post to a permanent page, available at this page.

Eagle outline for the Evatron PC00 series enclosure

I found a neat plastic enclosure with a battery compartment that I plan on using for a current project. It is made by Evatron and comes from the PC00 series (I picked a PC003N). Below is a ZIP file containing the case drawn in Eagle to measurements from the datasheet. A dimension layer is included that makes the most of the internal space. Download the Eagle board file - free for any use (but credit is nice)

Updated Eagle library posted

I have just uploaded the latest version of my Eagle library, containing a bunch of new parts. These include: Maxim DS1337 RTC RFM12 radio module (with pins) Keystone CR123A battery holder Memsic MXC6202 I2C accelerometer ON Semi CAT6219 500mA LDO regulator Texas Instruments TSL2560 / TSL2561 light-to-digital converter Maxim DS620 Low-Voltage, ±0.5°C Accuracy thermometer The library can be found on this page.

PCB antenna design

One of the circuit boards I’m developing would benefit from an onboard antenna, so I started hunting for design tips. The following three PDF documents do a great job of explaining the basics: Freescale “Compact Integrated Antennas“ Kent Smith “Antennas for low power applications“ Ingecom “V / UHF Antenna Design“ I will update the blog once the circuit board is designed and I have managed to test range and effectiveness.

PCB0002 - LED matrix

It has been ages since I have updated this site. I have started to document some of the PCBs I have created The first is an 8x8 LED matrix, with code for some whizzy effects. More information and downloads on this page. If anybody wants to see the code, I could tidy it up a bit and post with some explanation.

Cooking with gas, my first SMD board

My first bunch of boards arrived back from BatchPCB and I’m really impressed. Great printing for the silkscreen and a really professional looking product. One of the boards I ordered was a breakout board for the SMD PIC 18F2321, the first surface mount board I have tried.

Using the hardware USART with BoostC and a PIC

This post looks at what is needed to get a serial connectiong working with BoostC using a PIC with a hardware USART. A later post will cover the BoostC software implementation, when I have finished figuring it out. By the end of this post there will be a PIC uC talking to Hyperterminal on the PC using less than 50 lines of code.

Eagle components library added

A very short note to say that I have (finally) published my Eagle components library on this site. Right now it doesn’t contain many parts, but I will add to it as I make more boards.