tag:blogger.com,1999:blog-54855490032428973892024-03-05T16:49:48.971+01:00Tom's ProjectsThis is a blog about my electronics projects and my interest in toying around with electronics hardware.Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.comBlogger39125tag:blogger.com,1999:blog-5485549003242897389.post-48475932545864839532016-05-06T19:23:00.000+02:002016-05-06T19:23:23.448+02:00A Low-Cost EggPlotter
Features
Plots on spheres and eggs, similar to the EggBot
Uses low-cost components (total cost around 25 €)
Software is written as an Arduino sketch
But: NOT as accurate as the original EggBot
Introduction
I have admired the idea of the EggBot for quite some time. The original device is an art project of Bruce Shapiro, apparently conceived in 1990. Read about the history of it Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com13tag:blogger.com,1999:blog-5485549003242897389.post-13259991782001458672016-02-08T16:06:00.001+01:002016-02-13T16:11:21.757+01:00WiFiRGB - A WiFi-enabled RGB high-power LED
Features
Simple hardware, using pre-fabricated modules
Controls an RGB LED via any recent browser, any operating system
WiFi credentials can be configured via browser
Software is written as an Arduino sketch
Introduction
Some time ago I read about the cheap and easy to use ESP8266 WiFi modules and I had to have a couple of them. So I ordered two ESP-01 modules. At the time I had no idea Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com6tag:blogger.com,1999:blog-5485549003242897389.post-48986715014123250272015-01-06T12:29:00.002+01:002016-11-24T23:37:28.427+01:00A MythTV Remote Control without LIRC - Power Switch Addon
Overview
This is a little add-on for my MythTV remote control. It adds a hardware power switch feature. This means that you can switch the PC on even if it is completely shut down. There is just one condition, which is that the remote control receiver must have power, supplied through the USB port. On most modern mainboards, this is an option in the BIOS settings. The additional hardware is Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com1tag:blogger.com,1999:blog-5485549003242897389.post-60570606196890876632015-01-03T01:41:00.000+01:002017-09-01T09:19:35.182+02:00A PC Watchdog
Project Features
Automatically resets a crashed, frozen Linux PC
Simple
Uses a cheap USB-to-serial adapter
Introduction
For several years I have been using a MythTV Linux server to record television shows. It works very well and I like it a lot. It has one major problem though: Sometimes it locks up. I suspect that this happens when it changes channels and signals are weak (e.g. due Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com5tag:blogger.com,1999:blog-5485549003242897389.post-28417851142363316792014-12-22T01:27:00.001+01:002016-11-24T23:34:06.482+01:00A MythTV Remote Control without LIRC
Features
Relatively easy to build
Emulates a keyboard, so it needs no driver
Costs around 10 €
Is easy to configure, in under one minute
Works with most remote controls
Can easily be customised for other HTPC software
Introduction
I was always very fascinated with Objective Development's software implementation of a USB driver for Atmel controllers called V-USB. On their web site, they Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com5tag:blogger.com,1999:blog-5485549003242897389.post-8134037613349391542014-10-31T17:07:00.000+01:002014-11-30T23:15:16.193+01:00The Eyes - A Last Minute Halloween Effect
Introduction
Halloween is a rather new tradition in our part of the world, but my family is very enthusiastic about it. Tombstones are built, bones are scattered in our front garden and a fog machine is kept in the basement for just this one day of the year. This time I thought that I could contribute a little LED effect. My idea was to use a couple of red LEDs to create a red-glowing eye Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com0tag:blogger.com,1999:blog-5485549003242897389.post-32451208513864351502014-02-06T23:09:00.000+01:002014-05-25T10:43:40.809+02:00The Morse Thermometer - Part 3
Putting it all together
In part 1 and part 2 of this posts I investigated and designed the components for a solar-powered Morse thermometer. In part 3 everything gets connected.
In order to get the most out of the collected sunlight it is important to use as little power as possible. A red LED is a good choice here, because it only has a forward voltage of 1.7 Volts. So it will consume only Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com3tag:blogger.com,1999:blog-5485549003242897389.post-60229792927026912272013-05-24T23:51:00.001+02:002013-05-24T23:51:18.669+02:00How to Do ISP Programming – Part 4: Fuses and Troubleshooting
Setting Fuses
As mentioned before, fuses are used to set a couple of things that might need to be set before the actual software starts to run. As a beginner you should not tinker with most of those settings, because it is possible to lock yourself out of in-system programming.
The most dangerous fuse bits in that respect are SPIEN (SPI enable) for obvious reasons and RSTDISBL (Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com2tag:blogger.com,1999:blog-5485549003242897389.post-36520423174421639002013-05-24T23:30:00.003+02:002013-05-24T23:30:41.275+02:00How to Do ISP Programming – Part 3: Software Usage
Installing the Software
As mentioned, there are many options when it comes to software. One standard program, which is available for many operating systems is avrdude. Unfortunately, it is a command line tool, which makes it less than ideal for beginners. But there are GUI frontends available. I decided to use AVRDUDESS for this tutorial. And it is quite easy to use.
But first, Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com8tag:blogger.com,1999:blog-5485549003242897389.post-6871030299206399282013-05-23T23:40:00.001+02:002013-05-30T19:10:53.811+02:00How to Do ISP Programming – Part 2: Hardware Considerations
What Hardware do I need?
Obviously you need the controller. This can be any Atmel ATtiny or ATMega. You need a circuit board to put the controller in (the "target board") and you need an ISP programmer. Since ISP uses a serial format, the programmer can be rather compact.
There is a wide variety of programmers on the market, from full featured expensive to cheap and simple. Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com5tag:blogger.com,1999:blog-5485549003242897389.post-36760891140170631712013-05-20T20:39:00.003+02:002013-05-24T23:54:56.015+02:00How to Do ISP Programming – Part 1: The Theory
Introduction
Many of my projects use AVR controllers from Atmel. And they need to be "programmed". This means that the software needs to get written into their internal program memory.
For beginners, this can be a major stumbling block in any project. And I do get lots of questions in connection with programming. So I decided to write this tutorial. But my intention is not justTom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com5tag:blogger.com,1999:blog-5485549003242897389.post-81540868907337739672013-05-02T22:25:00.000+02:002013-05-02T22:34:19.641+02:00Another simple electronics project for kids
Project Features
Simple
Cheap
Doesn't take long
Can be done by children (with a little help)
Introduction
One of my sons recently started to nag me. He wanted to solder something. Initially I had no idea what he could solder and I thought he was simply bored. But he kept going and I knew I had to find something. Finally I remembered that it would be "Blue Night" soon and that Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com2tag:blogger.com,1999:blog-5485549003242897389.post-48012345514138931172013-04-10T22:16:00.002+02:002013-04-10T22:16:42.289+02:00Connecting an ISP Programmer to an ATMega8Several people asked me how you connect an ISP programmer to an ATMega8. It never occured to me that this could be a problem for anyone. But anyway, here is a schematic.
Over time, I will write a tutorial on how to program AVR controllers.
Please note that the header shows Atmel's standard pinout for the 10-pin ISP header. Most programmers use that same pinout. But to be safe you should check Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com14tag:blogger.com,1999:blog-5485549003242897389.post-19000281329171870152013-04-02T20:53:00.001+02:002013-04-02T20:53:53.932+02:00A Beginner's Guide to Driving LEDs - Part 4
The transistor as current sourceIn part 3 of this tutorial we looked briefly at several current sources, which contain integrated circuits. In this part, we will look in more detail at a simple current source built from a transistor, a zener diode and two resistors.
The basic principle for this circuit is to start with a fixed reference voltage. This voltage is then translated to a fixed Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com0tag:blogger.com,1999:blog-5485549003242897389.post-55839528243324422192013-03-31T01:35:00.001+01:002013-04-02T21:04:38.531+02:00A beginner's Guide to Driving LEDs - Part 3
Actively Stabilizing the Current
In part 2 of this tutorial we found that there are situations, when a simple resistor is not good enough to keep the current through an LED stable. There are countless ways to stabilise the electrical current actively. Some are simple, some are complicated. I will show a few here.
Note: The LED in the following schematics generates red light and has aTom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com0tag:blogger.com,1999:blog-5485549003242897389.post-30222373161105736172013-03-24T22:05:00.000+01:002015-01-03T21:35:14.919+01:00A Beginner's Guide to Driving LEDs - Part 2
Resistance is not futile...
Part 1 of this tutorial showed why using an LED is not as straight forward as using a light bulb. Now we have a look at different ways to operate an LED.
The simplest and well known way to operate an LED is to add a series resistor. It is quite easy to determine the value for this resistor:
Start with the operating point of the LED. E.g. an LED Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com0tag:blogger.com,1999:blog-5485549003242897389.post-64687807814843878932013-03-24T21:36:00.000+01:002013-03-28T12:41:22.073+01:00A Beginner's Guide to Driving LEDs - Part 1
Introduction
LEDs are just great. Nowadays they are cheap, durable and power efficient. You get them in all colours, shapes and sizes.
But along with all the advantages comes a disadvantage, too. LEDs have special demands when it comes to their power supply. In most cases, this is not too bad. But many beginners in electronics have problems to understand those requirements. With this post ITom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com0tag:blogger.com,1999:blog-5485549003242897389.post-71794178775683632332012-12-17T00:23:00.001+01:002012-12-25T01:50:05.459+01:00How to Build a Simple LED Cube 4x4x4 - Part 4Software
The software is derived from my earlier LED cube, the charlieplexed version. Of course the "hardware layer" had to be changed, because physical control of the LEDs is different. But the rest is very similar.
To add a bit more structure, I partitioned it into several files. There is the main routine (in LEDCube444.c), the file HWControl.c for low level hardware support and a collection Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com84tag:blogger.com,1999:blog-5485549003242897389.post-89211723509390444282012-12-03T01:28:00.000+01:002012-12-17T00:25:05.040+01:00How to Build a Simple LED Cube 4x4x4 - Part 3Connecting the Electronics
There
isn't much, really. First, solder the microcontroller's socket to the
perfboard, then the socket of the driver. I didn't use a socket for the driver
initially, which I regretted later...
Here is a schematic.
If you do this in a clever way, there will not be too
much effort in connecting the driver to the controller. Port B controls the common cathodes,Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com25tag:blogger.com,1999:blog-5485549003242897389.post-87313691427726483552012-11-22T23:22:00.000+01:002012-12-03T01:32:18.256+01:00How to Build a Simple LED Cube 4x4x4 - Part 2Building the Cube Structure
In part one we prepared all LEDs for the assembly of the cube. Now, we start in earnest...
Step2: Build the groups
Each group consists of eight LEDs. Here they are:
You need a template to assemble the LED groups. My LEDs are 5mm, so I drilled a set of 8 5mm-holes in two rows with 4 holes each into a piece of wood.
Insert 4 LEDs in the upper row of theTom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com22tag:blogger.com,1999:blog-5485549003242897389.post-23705097690684320712012-11-22T22:53:00.000+01:002012-12-01T23:08:51.731+01:00How to Build a Simple LED Cube 4x4x4 - Part 1
Project Features
Easy to build
Only two active components (apart from the LEDs, of course)
Includes detailed build instructions, schematics and software
Introduction
When I posted my charlieplexed 4x4x4 LED cube I did so in order to show an alternative implementation for such a cube. Its unique feature is that it only uses 9 controller ports. For some reason it gets a lot of interest Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com104tag:blogger.com,1999:blog-5485549003242897389.post-79073016720705228902012-10-23T21:40:00.000+02:002012-10-23T21:40:35.074+02:00100000 Viewers!!!Wow! According to Youtube's statistics, the video about my charlieplexed LED cube was watched over 100,000 times. Unbelievable! Unreal! Unforeseen!
Thanks for all your interest and all the positve feedback. I don't know if I will be able to top that, but I will keep trying,Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com10tag:blogger.com,1999:blog-5485549003242897389.post-70005574046670883222012-10-20T23:07:00.002+02:002012-12-17T01:20:08.479+01:00The Charlie Cube Mark II: 4x4x4 - UpdateUpdate
Build this simpler version instead!
Introduction
When I wrote my post on my charlieplexed LED cube, I never meant to publish build instructions. There are plenty of instructions around and a regular LED cube is much easier to make.
Instead, I wanted to show that it is possible to use charlieplexing for such a cube. And I wanted to share my thoughts on how I got there. So I never Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com25tag:blogger.com,1999:blog-5485549003242897389.post-61471620720918727552012-10-16T21:20:00.001+02:002015-09-21T20:03:12.904+02:00A Charlieplexed Knight Rider Light
Features
Low cost and low part count
Four different flashing patterns, easily modifyable
Speed control and pattern switching via pot
Introduction
This is nothing special, really. "Knight Rider lights" or "Larson Scanners" seem to be very popular microcontroller projects. I guess they are the next step right after the blinking LED (a.k.a. the "Hello World" program for microcontrollers).
I Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com37tag:blogger.com,1999:blog-5485549003242897389.post-47964950369360203262012-07-15T17:44:00.002+02:002014-05-25T10:45:32.320+02:00The Morse Thermometer - Part 2
Reverse Engineering a Solar Lamp
Part 1 of this post is a write-up of my project for a thermometer with Morse code output. But I was not satisfied with the relatively high power consumption of the circuit, so I decided to use a solar cell to supply the circuit.
A cheap source of solar cells these days are solar garden lamps. You get them for very little money in garden centres and DIY shops.Tom F.http://www.blogger.com/profile/17222198163820671255noreply@blogger.com15