More to come...

Who is ZL2PD?

For anyone remotely interested in the person behind this website, a few more details can be found here.

Email ZL2PD?

Links to other websites:

Logging the Changes:

7.3.16: Added source code files and a bit more info to the multi-feature si5351 VFO, and added details of a second si5351 VFO

28.2.16: The ZL2PD si5351a VFO, GPS frequency reference, Li-Ion battery monitor, CS2000 signal generator were added to the website

15.9.15: The OBD-2 speedometer and a digital QRP SWR meter were added to the website

18.6.15: Soldering stations, four dot clock and soldering iron cleaner added

17.3.15: In which Andrew described how Yahoo sent his email to another continent!!

30.10.14: Lots of new projects added


Welcome to my website. This site describes a number of my designs mostly related to amateur radio as well as for other purposes or needs that have captured my attention.

What's New?

2016 has kicked off with several new designs. The latest ones include:

A new si5351 dual output VFO/BFO with more features than I can
list here. It uses a compact backlit Nokia 5110/3310 graphics LCD
and it covers all of the usual amateur radio bands, and more if required. The power consumption is low as well (Just 30mA at 3.3V)
so it's suitable for QRP, and it's cheap to build. I've uploaded the
Bascom source code and the various support files, too. The details are here...

If one new si5351 VFO/BFO was not enough, here is another!! Yes, a second single band si5351 dual output VFO/BFO using less than 20 components. A small 8-pin ATtiny85 does the work. An I2C alphanumeric LCD displays the frequency and tuning step size, and it sports an integrated S-meter/RF power meter display as well.  Same low power consumption. And, yes, the Bascom source code software is all there too. So now, you have a choice of si5351 VFOs on my website. The details are here...

Next up, a simple GPS-based frequency reference for the workbench,

This uses a low cost GPS receiver to produce a highly accurate 24MHz signal. It's portable, with a Li-Ion battery, battery charging board and battery monitor. And it's all packaged up in a 3D printed case. The details can be found here.

In addition, I've also added full details of the simple Li-Ion single cell battery monitor that I developed for the frequency reference. It can display the charge state of the cell (Full, % remaining) as well as reporting the battery voltage.

It's all done with just a single 7-segment LED display. How? Well, read on...

If all of this is not enough, I've written up an earlier design for a compact digital RF signal generator using a Cirrus Logic CS2000 chip. It's compact, with everything inside a small 3D-printed case. It generates a 3.3V squarewave output from 1.5 to 160MHz (although the specs on that chip claim it is limited to 75MHz) and draws less than 20mA from a 4 - 15V DC supply.

It's really the result of a tale of woe and misfortune, but the circuit works... More details here.

These new designs follow on from the information that I published here not so long ago:

A speedometer for my new Mitsubishi Pajero. Sounds crazy, I know. Why design a speedo for a car? But Mitsubishi designed the instrument panel in my 4WD so it's impossible to read it when the sun's out. It's awful if you're wearing sunglasses which, yes, we do quite often here in the desert. In order to stay alive on the roads here, I must be able to read my speed at a glance... I've explained this in more detail on here on this page. At heart, this is a design for a simple OBD-II display, and just as useful to display other data in other types of vehicles.

And here's another new design of mine. It's a really small digital SWR meter
for QRP (low power) transceivers and transmitters. It's compact, lightweight, powered by a single AAA battery. It uses a super-bright and easy to read OLED graphics display.

Did I mention it's small? And weighs just 50g ?

More designs coming up soon, I hope.

How to Navigate the ZL2PD Website

You'll find the complete list of these designs down the left hand side of this page. Simple 'click-on-em' buttons will lead you to each design. Schematics and other drawings are to be found all over the site, as are photos. Want to see the details close-up? Then just "right-click" on the image or schematic or whatever. Chances are, you'll now be able to see much more detail. And you can download it too, if you wish. 

To date, the details and designs here on my website include:

And there are some new designs, just added. See below...

A Magazine-like Website

Over time, I've also begun to realise that my writing style on this website is a little bit different to that you might see on other more traditional websites. I think my website is starting to develop into something more like an online magazine which has (roughly) updates every two or three months, as new designs are completed.

That writing style is partly due to my desire to clearly explain how to duplicate a design. But is that what I should be doing? Or are shorter descriptions of my designs all that's required?

And if this website isdeveloping into something like an online magazine, I guess that makes this intro page a bit like a rolling editorial. Hmmm.

Other recent additions to the ZL2PD website ...

A suite of three different designs for temperature controlled soldering stations, with a detailed design for the most compact unit. It uses a single 8-pin ATtiny25 microcontroller and not much else, and it is packaged in a compact 3D-printed enclosure, also of my own design. (Right-click the image for a closer look or visit the web page)

That's something you'll be seeing more of on this site - cases designed and built using my 3D printer. I purchased a Printrbot Simple Metal 3D printer kit late last year, and after building it and getting it running with the 3D design software I use (The incredibly good freeware DesignSpark Mechanical V2 software), I've been making all sorts of things with it.

For those looking for something a little different, here is a Four Dot Clock which uses just four cheap LEDs (Four dots of light, if you will) to display the time. It's surprisingly accurate. I only adjust it now about once every six months.

More interestingly, perhaps, is the fact that, unlike most clock designs you might have seen, this one does not require another chip to actually do the timekeeping. The clock's ATtiny45 does all that, and more.

And then there's this accessory for the temperature controlled soldering iron I mentioned earlier. It's a tip cleaner accessory using an easy to obtain item from the supermarket, and printed on a 3D printer.

Of course, all of the other designs are still available to browse and build, each listed over to the left in the index. Help yourself!

What else is on this website?

Aside from a page chattering on a bit about Yahoo and mail, my website describes a variety of projects related to my hobbies of amateur radio and electronics. These include circuit diagrams, descriptions of how they work and what they do, PCB layouts (sometimes), construction details, and software for designs which use microprocessors or microcontrollers.

For the record, the microprocessor designs here use the AVR chips including the ATtiny15, ATtiny25, ATtiny45 and ATtiny85, ATtiny2313, ATtiny26, ATmega8, as well as some earlier designs which use 8051 processors including the 80C552, 80C751, 80C51, 80C52, AT89C1051, AT89C2051, and AT89C4051, and so on. Almost all of my 8051 software is written in assembler while the AVR code is a mix of assembler and BASCOM (Basic).

New Designs Coming Soon...

Here are a few things that I might finish soon. However, what tends to happen around here is that, suddenly, something attracts my attention, and I end up putting some time into that instead!  

Example image - aligned to the right

But, if I was to hazard a guess on what will appear here next, then....

Some details about building a new kit transceiver that's not particularly well known...

Homebrewed battery holders (Try to buy a battery holder in the desert!), and

My version of an LC meter

And there are a few other projects waiting in the pipeline. 

But really, it's all a bit of a mystery what will arrive here on my website next. Just depends.

Stay tuned... 

The Legal Stuff

You use the information on these web pages at your own risk!

You may use the information provided here for personal or educational purposes but you may not reproduce it in any form or use this information for any commercial purpose without first obtaining written permission from the copyright holder.

There is no warranty or guarantee, either expressed or implied, covering any information of any kind which may be available from this website, or that designs and information provided on this website are free from patent or intellectual property rights of the author or third parties.

Should the information contained on this website be used by any party, that party shall by using the information provided be deemed to take complete responsibility for all risks and liabilities associated with its use and hold the author of this website harmless in the event of any claim, loss, liability or expense associated with any such use.

The rights of copyright over the contents of this website, unless otherwise noted, are claimed by Andrew Woodfield ZL2PD.

Example image - aligned to the right