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.
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)
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.
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.
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.
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.
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.