Archive for the 'Electronics' Category

The ESR electronics Tricorder: Update

In case anyone is wondering, the ESR project isn’t dead, I’m just waiting for some small OLED displays to show up. I ordered these a while back (in December), and they have yet to arrive. The plan is to use some of the empty space on the front panel next to the display already slated to go there. Here’s what it looks like:


It has a 128 x 32 display space with an I2C interface. You can find this OLED display on eBay, and they go for around $4 each.

It was originally slated to arrive by the 3rd of January, and the tracking info says it’s supposed to show up today, so we’ll see.


Clever Arduino Case

One of the challenges that seem to keep coming up when working with an Arduino is where to put it so that it won’t get banged up on the workbench or tossed off the dining room table to make space for dinner. I’ve written about using wood, and my books give examples of various types of enclosures (everything from PVC tubing to pro-grade test instrument enclosures), but what other options are available? Is there an off-the-shelf solution? Turns out there is, if you have an R2 or R3 type Uno (or Duemilanove), and best of all it’s inexpensive.

Continue reading ‘Clever Arduino Case’

New series: Arduino Test Equipment

The ESR electronics Tricorder, Part 1

In this article I describe the beginnings of a device that I like to think of as a Tricorder for electronics. This is the first of a three part series in what will (hopefully) be the start of a series of articles that describe ways to use Arduino boards and AVR microcontrollers to build useful, low-cost test, measurement, and control devices.

For additional details and definitions be sure to check out my books “Practical Electronics: Components and Techniques” and “Arduino: A Technical Reference“. Both are available from O’Reilly, Amazon, Barnes and Noble, and numerous other places where fine books are sold.

Continue reading ‘New series: Arduino Test Equipment’

More CHIP computer notes

After getting the VGA “DIP” add-on PCB installed and running I’ve been playing around with the CHIP a bit more. Between the day job and a couple of books in progress I don’t have a whole lot of spare time, but I did find out a few interesting things. Continue reading ‘More CHIP computer notes’

The C.H.I.P. has arrived

A while back I discovered the C.H.I.P. single-board computer from the Next Thing, Co.. After checking out their web site and doing a bit of research I pre-ordered four of the $9 units. When they arrived about 2 months ago I eagerly picked a box at random and pulled out the small PCB inside. Continue reading ‘The C.H.I.P. has arrived’

Tiny Power: Coin Batteries

They are all around us. In our watches, laser pointers, hearing aids, toys, calculators, remote control units, and more. Yet we don’t often notice them or give them much thought until they stop working. And then it’s time to poke through the selection at the local drug store or big box retailer, hoping to find one that has the same cryptic number (or at least something that claims to be compatible).

Originally developed for use in hearing aids, so-called coin and button batteries are, as the names suggest, small disc or button-shaped batteries. They come in a variety of formulations and shapes. They can be stacked in series to produce a higher voltage, or wired in parallel for increased current. If purchased in bulk (such as through vendors on Amazon) they are also surprisingly cheap, and they pack a lot of energy into a very small package.
Continue reading ‘Tiny Power: Coin Batteries’

Cool new tool

In my book “Practical Electronics: Components and Techniques” I describe how to use a standard bench vise or an X-Y cross-slide vise and a rotary tool (aka Dremel tool) to make precise cuts in various types of materials. Well, I know I’m not the first person to come up with something like this, but I recently came across a tool from China that does the same job as a vise, and does it a bit more elegantly for certain applications. This is it, mounted on the side of a small metal desk in my shop:


The clamp head swivels using a ball joint, and it can be removed and stored when you don’t need it. I can imagine that it would be useful for a number of applications besides electronics. Jewellery makers and other crafty people might find it handy. If you are working with a tubular work piece like brass or a PVC pipe you could mount the work in the clamp to keep it steady.

It’s not a cure-all, as it does have a problem squeezing some rotary tools into the clamp ring. It comes with nylon inserts that will help hold the tool and compensate for the tool size, and the clamp bolt could be longer. I can’t fit one of my rotary tools into this clamp, but as you can see it does just fine with a smaller tool. The pictures on the Amazon page show another example.

You can find the tool at Amazon. It sells for about $23.

Follow Crankycode on

Little Buddy

An awesome little friend

Jordi the Sheltie passed away in 2008 at the ripe old age of 14. He was the most awesome dog I've ever known.