RN2483 / RN2903 Firmware upgrade guide

February 13, 2018

The Microchip RN2483 and the RN2903 are Low-Power Long Range LoRa® Technology Transceiver Modules, in the same package and Pin compatible. The RN2483 is intended for the 433 MHz and 868 MHz Frequency Bands (Europe), while the RN2903 is for the 915 MHz Frequency Band (US, Taiwan). I used the RN2483 in my first LoRaWAN project, some time ago. While LoRaWAN technologies have seen an impressive recent boost and Microchip’s…


Morse encoder

August 17, 2016

The morse code encodes the latin alphabet comprised of 26 letters to a binary base. Traditionally, the destination set used dots and dashes, making the encoded letters easy to transmit as signals both over radio and wire. But any binary set of symbols can be used instead. For other languages with more than 26 characters, or for special characters, there is an extended set of morse binary combinations something we…


Voronoi diagrams and OpenLayers 3

July 24, 2016

OpenLayers is an opensource javascript library for rich web-based geographic applications. I recently had to represent temperature readings on a map. The first idea was to use heatmaps, due to their nice blur and colour gradient effects. There is native support for heatmaps in OpenLayers 3: Demo code on JSFiddle. function initHeatmap(src) { return vector = new ol.layer.Heatmap({ source: src, blur: 2, radius: 8, weight: function(srcObject) { return parseFloat(getDoseRate(srcObject.get(‘averagecpm’), srcObject.get(‘factor’)))…


DIY Dosimeter Geiger Counter KIT1.0

March 8, 2015

Note: there is a newer version of this project, KIT1.1, see it here If I was to give this project a version number, the closest match would be the uRADMonitor model B. Finally an open source compact radiation dosimeter, that has an LCD and thus allows mobile use, but also comes with an Ethernet adapter so it can do radiation monitoring (uRADMonitor compatible). Yet, this is not quite the uRADMonitor…


Virtualmin Git return code 22 fatal: git-http-push failed

December 12, 2014

Installing GIT from Virtualmin is easy. You just need to go to Edit Server->Enabled features->Allow Git Repositories Create a repo by going to Services->Git repositories: Then go to Edit Users->select a user->Other user permissions and grant them access to your new repo: You are now ready to add your local code to the new repo: cd ~/firmware git –bare init echo hello > hello.txt git add hello.txt git commit -m…


Infused™ project

March 28, 2014

Infused™ is about passion for design, music, digital, programming and alternative culture in Timisoara, Romania. Structured as a set of interviews with people involved in the act of creation regardless of its final form, the first video covered Flat UI & Minimalism, featuring Madalin Gageanu and Adonis Raduca: I was excited to get an invitation to participate to the second episode. This time the subject was focused on Android software…


Implement Photoshop-like Curves with Leptonica

September 5, 2013

If you’ve used Leptonica, you probably know it’s a great library, but when you want to use it to replicate Photoshop like effects, you will quickly get to want more than what the library provides by default. Take the pixGammaTRC primitive as an example: If you want to modify the lightness of your image, (making it brighter or darken it), or even a simple contrast this might work good enough….


Enhance saturation in images programatically

August 9, 2013

Increasing the saturation in an image is equivalent to increasing the “amount of color”, while a completely desaturated image would be a grayscale image. See the images below: Normal Saturated Desaturated Grayscale Logic and Implementation Algorithm The images are composed of pixels. For a RGB24 image, each pixel is a set of 3 bytes, 1 for each of the three color channels: red, green, blue. 1 byte (or 8 bits)…


Global radiation monitoring network

July 11, 2013

EDIT: there is a dedicated blog on this project, here. Make sure to follow it for latest news. A few days ago I announced my intention of creating my first crowd-funded project, but I didn’t tell you what was it about. Well, I’m planning quite a challenging project – to bring my uRADMonitor to a global scale, and create a network of distributed detectors, with data centralized on one server,…


Leptonica saturation deficit workaround

June 28, 2013

While working with Leptonica I had the unpleasant surprise to notice that the saturation function pixModifySaturation was not really working properly (or at least not entirely as expected). First I didn’t even know what was wrong, I just felt it didn’t look right, then I saw that by transforming the saturation in Leptonica with pixModifySaturation , the contrast would be partially lost. Debugging the issue, and using different photos for…