Generalizing Dynamic Programming
- Using dynamic programming techniques to optimise general compute efficiencyDynamic programming is an approach to efficiently implementing certain classes of algorithms. As a feeble excuse for not noticing this earlier, the term is a little confusing: it isn’t about programming or about doing it dynamically! It was invented in the 1950s by Richard E. Bellman whilst working for RAND Corporation. Apparently he deliberately named it obtusely to avoid his work being considered research! I discovered this term recently when looking into existing research about algorithm optimisation and specifically why the systemic memoisation in NetKernel can optimise solutions to certain problems particularly well.
Travelling Salesman Problem
- Study of TSP running on NetKernel with cache replacing dynamic programmingThis paper offers an analysis of the application of NetKernel and Resource oriented computing to the well known Travelling Salesman Problem (TSP). This discussion ignores the many approximate approaches to solving this problem which are necessary for real-world problems of any significant complexity. The aim, however, is to show how ROC can automatically optimise a solution which it knows nothing about other than empirical data collected during execution. The algorithm structures the problem into sub-problems many of which overlap with each other - this occurrence is called overlapping subproblems.
Building a Pi Zero Photo Frame
- a self contained photo frame connecting to an RSS feedThis project builds a self-contained photo frame using a Raspberry Pi Zero and an old monitor. (Old monitors are better as the 4:3 ratio suits a mix of vertical and horizontal oriented photos better than a 16:9 ratio.) Figure 1: Finished Frame on wall Hardware Parts List Raspberry Pi Zero with micro SD containing Raspbian Power supply for Pi (see below) USB WIFI dongle VGA computer monitor VESA wall mount Custom made photo frame to fit monitor HDMI to VGA adaptor I had a photo frame made by a framing shop with the inner dimensions of the monitor.
Simulating Pub Skittles
- to discover optimal playing strategiesTwo years ago I created a 2D simulation of the game of pub skittles in an attempt to find the optimum strategies for playing. The simulation used parameters measured from our home alley. (We play in the Malmesbury skittles league at the Volunteer Inn, Great Sommerford.) Different alleys have different characteristics. For example different sized and shaped pins, different balls and different conditions of alley. I had some success with this simulation.
Radar Speed Camera Rebooted
- building a radar speed gun with a Raspberry PiBackground This post is a follow-up from my previous post Building Radar Speed Camera and Traffic Logger with more information, improved design and experience from using the device in the field for nearly 2 years. This project is a self contained speed radar that can be used to give realtime traffic speeds, log traffic flows and statistics over a period of time and also possibly capture speeds of other objects in sporting environments, for example, though I haven’t specifically tested and tuned the code for this.
Power Regulator repair on Photon
- How to bypass and replace power regulator on Particle PhotonI accidentally shorted the 3.3v pin in the Particle Photon with ground. Within a second a puff of smoke rose from the circuit board and the photon no longer worked - when I connected power nothing happened, no LEDs lit and no boot. After a little looking around I discovered that the problem was likely the regulator which lowers the USB input voltage VIN down to 3.3V which all arduino like platforms use.
Published Dec 21, 2016 1 min read internet of things
Home DashboardBackground There is something immensely satisfying about having something to hold which has been hand crafted. Working with code most of the time it’s rare to get an outcome that is tactile. This project recreates a Hive-like user interface experience with a few readily available components. These components connect easily to a micro-controller such as the Particle Photon. Figure2: Hive smart thermostat Figure1: Dashboard Construction Guide Parts List Photon Particle 500mA micro-USB power supply Breadboard 1602A LCD Display with I2C interface rotary encoder module knob for rotary encoder 2x 0.
Published Jul 15, 2016 2 min read internet of things
Aquarium Lighting ControllerBackground I’ve had a modest home aquarium for a many years. It has always been lit by a specialist aquarium fluorescent tube. This gave out a nice light which both helped plants to grow and counteracted the excess of green caused by plants an algae. Figure1: Spectrograph of Hagen Aquaglow fluorescent tube There were two problems with this fluorescent lighting solution however. Firstly, it switches on and off instantly which can be quite unnatural and startles the fish.
Published Jul 1, 2016 10 min read internet of things