Tinker Niche

 I have been using Raspberry Pis for a long time now. Used many of the commercially available cases. RPis can be run headless (without a display) or an HDMI/SPI display can be used. There are many cases that are available for the 5" displays, etc. But it would definitely be nice to have small display with maybe an LED and touch support. Say like the commonly available 16x2 char displays and a WS2812B led and a button. This led me to search for a similar thing on the Internet and finally to a ThingSurf. Found this:  Design on Printables webiste for a Raspberry PI 4  with display .  The Design is by user guytas on printables  and already had all the things I needed. This was locally printed on a Creality Ender. The 16x2 display fit nicely. But as there was a need for an RGB did some "jugaad" and fitted an RGB Led below the button hole and a couple of capacitive sense buttons below the casing. Wrote a small program to showcase all of the features. The program shows...

Building the PlotClock by Joo from ThingiVerse  with English Character support Plotters are fun things. One can move in a 2D space and do very interesting things. Been fascinated by plotters from a long time. Notable mentions like the Drawbot, AxiDraw, EggBot, etc. Always wanted to build a small inexpensive one which did not require too many components or a lot of domain knowledge. One of my favourite past-times is to ThingSurf ie check which open source designs are available and try to make them, either on Thingiverse or Printables, etc. Its a lot of fun and because these provide designs for real-world things,  one can study and learn from them and also extend them to do other things. There is also a requirement of a device that will be a low-power notice board, like a limited power device that will just consume power for a short time, do some useful work, maybe display a message and go back to sleep. Things written on a sheet of paper remain visible for a long time. So it wo...

The Implemented GPS device for speed, odometer, etc Building a Tracking and Metrics device using a GPS Module GPS (Global positioning system) modules are commonly used now a days for various tasks: navigation for maps, tracking speed, Geo-location etc. A couple of decades ago around 2002-3 they were not as common and there was need to use such a module for the Railways for tracking speed, odometer, maintenance information, etc. One recent usage of such a device can be found here on my blog:  Prototype Bangla Rail Remote Fuel Monitoring The above was the device that was built for the Railways. It had 2 parts to it, a front end part that implemented the UI and a back end part that would take the GPS module readings, analyse and store information, etc As this had to be a tiny system, a Linux SBC was chosen and in those days a tiny Linux distribution called CRUX was used. It could work off 16MB RAM and some 128MB flash and had support for USB flash for data storage. It was indeed ...

PxMatrix on ESP8266 connected to an 32x16 RGB DOT MATRIX 1/8 SCAN Panel It was always wonderful to see the numerous colour displays that display messages and animations on Dot Matrix Displays (DMD) in the commercial places. One useful thing would be to take an Off-the-Shelf Display and run fully controllable custom software rather than rely on some external products to do. Luckily found a display vendor who offered to give me some DMD as samples for experimentation. I was given a P10 32x16 pixel color DMD panel. I have experimented with Monochrome DMDs (maybe blog about this later) but the RGB display is another world all together. The Monochrome world does not have lot of open source software, the RGB world has PxMatrix, RGBMatrix and SmartMatrix. As I wanted the controlling entity to be super cheap which meant use of an 8266 I had to start with PxMatrix. Though there are better options than PxMatrix, the others use a more expensive controller. Its better to start with the lowest cost...

Photo by Dhiva Krishna on Unsplash It is both fun and pain to have an independent house. As much as there is freedom from a few things like nagging floor mates or just too many people around, there is also a pain to watch out for ourselves all around the house/neighbourhood. Houses used to be independent ones in the "golden" days where people would still live like Kings.  One such problem of such a house is parking space around the house and more so if the house is adorned by many open road corners which means more places to watch out for. People generally just thrust their responsibility on others and suddenly there is a new car in one of the empty places around. If the parking is transitory then it is kinda OK, say park for a short while and then move on. But nothing is known of such cars, they could be stolen, there could be people staying in them, any other activities, etc. So it is a headache if such a thing happens. One can call the police to solve the problem but i...

Leg Brake on a Bicycle  Growing up, there was a need to learn how to drive a geared motor cycle and also get a driver's license. There are two categories of two wheeler licenses: one for geared vehicles usually with leg brakes and one for auto/non-geared vehicles where the braking happens by hand and are simpler to operate. Driving license had already been acquired for the non-geared vehicle but due to lack of availability of a geared vehicle for practice, the acquiring of this license was taking quite some time. The main problem was adapting to braking a vehicle using the leg where one to respond differently and the conditioning takes some time. Unfortunately could not manage to get anybody/s vehicle for learning after many attempts. And at that time (1995 or so) bicycles were rather common and used for transport. So an idea was: why not add such a feature to a bicycle. A Hercules Town and Trek was also available. After some visits to the local bicycle shop and a used vehicle part...