Pretty (but dumb) LED MatrixThe picture shows the result of another workout with KiCad as executed by Seeed Studio and finished by me. This looks rather prettier than the original and was considerably easier to solder, not to mention more LEDs!However a few...

(Who knew that the Economics of Seinfeld was a thing? Given that it was the first link returned by Google, everyone but me I guess!)The idea of "marginal cost" is usually in mind when I'm preparing a PCB order from Seeed...

7x7 LED MatrixWhen I were a lad, LEDs were a big deal, literally: £1 each. Now someone in China manages to make a living selling them for £1 for 100. With inspiration provided by an Instructable, a rainy afternoon and...

Porting TTS to the ESP8266 processor has been on my to-do list for a while now, prompted by a comment on an issue I'd created to remind me. To do this, I realised that I'd have to reacquaint myself with...

One of the very few downsides of ordering PCBs from Seeed Studio's Fusion service is the shipping cost. While an individual PCB can cost less than $0.50 in multiples of 10, shipping to Western Europe can add another $20.One way to...

A unique feature of Internet-enabled "things" is that they often have an Internet connection and little else. First-configuration of these devices therefore presents a challenge, which most solve by creating their own wireless access point, to allow their owner to...

My title will no doubt remind regular readers of 2013's Weather Guy, a weather app which completely maxed out an ATMega328. Well it's had a technology refresh replacing Ethernet with Wifi, XML with JSON and AVR with ESP. A surprising amount of...

Some recent updates on the Github:Interrupted is now compatible with the Arduino (1.8.4 and above) and Energia (18 and above) IDEs. However you have to cut-and-paste the examples, for now.Tasks is also compatible with the Arduino and Energia IDEs, and (maybe)...

Mini-breadboards or DIY ESP Development Board?What do you do when you can't wait for cheap breadboards to arrive from China? Build a development board of course!The picture shows the work of an afternoon, to make a dev-board for the ESP-12 "IO Adapter...

ESP-12E with Adapter BoardThis neat piece of bargain-priced kit arrived in the post from China recently and today I got around to soldering it together. You-Tube-r RandomHacks has a nice video describing how he did it; I'll just summarize my experience...

All for less than a fiver!This little baby is an ESP8266-powered wireless mains relay from ITead. Although it comes with firmware installed which will suit most people, that requires an internet connection as it needs to talk to the Amazon...

Now even tinier!The photo shows an upgrade to last year's tiny ATtiny development board: now even smaller and with fewer components but with better breadboard performance!The schematic and board layout (for Eagle) along with gerbers can be found here. The pcb...

I have a love-hate relationship with our Raspberry Pi based Kodi Media Centre. On one hand it's cheap as chips and streams all the TV shows we could want (while not being a television) but on the other it's prone to regular...

It seems as if this blog has been veering towards software for a while now, and this post is about as far from hardware as it's ever been --- but hey, it has LEDs!The problem of the Dining Philosophers was first...

When it comes to debugging programs, the first tool in my toolbox for compiled languages like C or C++ is usually 'print'. I don't tend to bust out a debugger unless I'm in an IDE such as IntelliJ.This can pose...

It's very satisfying to build something for which you've all the parts to hand, there's no waiting around, just immediate gratification. This little build is such a thing. It's a dual-voltage (5v and 3.3v) power supply which plugs into a...

Interrupted is a new approach to developing low-power, low-latency Arduino sketches, which was motivated by two observations:That the default mode of programming for Arduino is busy-waiting, andThe runtime support for power management provided by avr-libc is basic, being charitable to it.Taken...

Very tiny! Recently I was surprised to discover that although I've made several projects using one, I'd never built a development board around the ATtiny85. With any project there are always design choices and a couple of important ones here were:Is...

An ATtiny84 and nrf24l01+ transceiverThe nrf24l01+ is an amazing little wireless transceiver which is (a) incredibly cheap (how about 10 for €8?) (b) can be put into an extremely low-power mode under software when not transmitting and (c) is controlled...

Well after almost a year I decided it was time to update this project with improvements to both its hardware and software.On the hardware side, the server is still the original Raspberry Pi model B, but I've mounted the nRF24L01+...

"What's a Computer?"This chimera is a microcontroller emulation of a UK101, an 8-bit microcomputer from the early 1980s. Needless to say I had one; it is a shocking thirty-three years since, as a spotty teenager, I soldered one together over the...

When I was a teenager Space Invaders arrived and changed the world. I must have put pounds into that machine in the local chipper, in the days when chips cost shillings. It never occurred to me that you could actually buy one...

Say what you like about the Arduino IDE, it's certainly lowered the barriers to entry for kids messing about with microcontrollers. Oh wait, that's not what I wanted to say at all...Sometimes the Arduino IDE is simply not enough. It just...

While not exclusively devoted to AVR microcontrollers, this blog has concentrated on them for one simple reason: they are very easy to get started with. Whether for beginner (Arduino) or professional (GNU make and gcc), the software ecosystem is very mature....

Energia pinout on TI LaunchpadThe MSP430 is a considerably easier target for RF24 than the ATtiny because it actually has its own SPI interface, see above.// Set up nRF24L01 radio on SPI bus plus pins 8 & 9RF24 radio(P2_1,P2_0);// sets the role...