Tinker Niche

  Raspivid Custom Annotations Raspberry Pi distribution is equipped with an executable called raspivid/raspistill which is used to capture and view video/still images from the RPI's CSI camera. The source code for this is available on the internet. It has various options like displaying video on HDMI, running TCP/UDP stream server, capability of reading encoded MP4 streams from the encoder, annotating the transmitted stream, automated still captures, effects, etc. Annotations like an OSD label can be provided on the stream being transmitted. Time annotations, etc can be enabled on the stream/video feed.  The only drawback is that annotations are updated every second on the feed. As there was a need to view various sensor information embedded in the video from a remotely operated vehicle, it would indeed be advantageous to extend raspivid capabilites. As a quick modification was intended, the relevant files were changed to use an IPC (InterProcess Communication) mechanism and a...

  Running GUI on sample hardware Sample GUI showing DDU interface for WAP Series Locomotive Driver Display Units are used in Locomotives to provide HMI for operating the locomotives. Various realtime sensor information of the locomotive/train are presented in user friendly interface on an LCD screen on an SBC.  The WAP Series locomotives use a variant of the MultiFunction Vehicular Bus (MVB) called MICAS. It is a master/slave realtime bus operating in the locomotive and beyond and can work over long distances (~4kms). Information is exchanged over the bus in the form of process data and messages. It supports connection via wire or fiber. There was a need to implement a Driver Interface while being interfaced to the MVB/MICAS. The design also had to be kept similar to existing products so as to retain locopilot familiarity and also provide similar features. Just as a fun exercise, an oscilloscope was used to dump traffic on the MVB from an available setup and manually validated...

The WDP4/WDG4 locomotive is a diesel locomotive used actively by the Indian Railways. It is a locally built General Motors Electro-Motive Division's GT46MAC (freight) and GT46PAC (passanger) variant. More details can be found here  WDP4/WDG4 info on Wikipedia The various gauges on this locomotive are Analog and there was a need to digitize them and provide a single console like is common on many locomotive Driver Display Units.  A commonly available industrial x86 SBC which could run Linux and a GUI was chosen. It was interfaced at a location on the loco rack where digital signals were available. It could show a locopilot various readings on the console: Speed, Brake Pipe/Cylinder pressure, BE/TE, Notch position and also various fault conditions. This DDU was used in a few locos and has worked reliably. Below is a picture of a physical meter and how it looks on the implemented DDU. WDP4 Locomotive Original Wikimedia image here

Introduction Nuvoton NUC980  is a 300 Mhz ARM processor. Has a host of peripherals onboard: 64/128 MB RAM, 2 Ethernets, 2 CAN masters, some 8 UARTS, SPI, I2C , etc It comes with Linux, uboot and a buildroot system for generating system assets. A popular board is the NUC980 IIOT board The major advantage is that this processor is available for a low cost of 5$ (2021) Intention Try and see how fast the system is Performance of python etc. Given that it was a low RAM system, how convenient would it be write a program in python. Maybe interface a device say a Display. Experiments The tar ball that Nuvoton provides is an approx 8 GB virtual machine running Ubuntu 18.04. One can run this virtual image on an VM emulator.  The recommended is VMWARE but it ran comfortably even in an Oracle VirtualBox VME. After logging into the VM and on running a make nuc980_defconfig it generated the uboot, linux and other assets. On Linux one can use nuwriter to flash the SPINAND.  A r...

Dot Matrix Clock IOT Dot Matrix Clock / Dot Matrix Display  (DMC) (DMD) An accurate clock for displaying time (Hours/second) and date would be a nice creation. Added advantage would be to have it connected on the internet and splashes messages to it. A WIFI based solution would be much better for easy access to the home/network ecosystem Using an accurate RTC like DS3231 and Wifi chip ESP8266, a PCB was fabricated. Also there was a need to make a good case to host the electronics. Acrylic case making is cheaper as compared to 3d printing. Found an enterprising acrylic fabricator who made an amazing case.  The power supply was embedded in the back of the case so it could be directly plugged into the wall socket or the ESP8266's USB power connector provided for at the side of the casing. Uses the MajicDesigns MD_MAX72XX library from here  MajicDesigns MAX72XX library The fabricated DMC looks as follows: Mains Enabled Clock The DMC can be run off either AC mains or an extern...

How to add Remote control (click/download) to an Off the Shelf Camera Digital Still Cameras (DSC) have good lenses and large image sensors. They take good pictures in varied lighting conditions There are many DSCs that are super cheap say like Rs 5000 to Rs 10000.  DSCs that provide WIFI and Remote Control option are also available, but they are expensive and of the range of Rs 20000 or more and also limited in exposing their APIs/control, etc. This was in 2019. Things might be different now. So modding/hacking a DSC to take pictures into its SD CARD and then download it remotely would be beneficial. This is simply done by using a servo as a picture taking plunger that is operated by an SBC say like an RPI and either by WIFI or via the internet, access a web server control mechanism that allows a remote user to click pictures or take videos. And then use a relay to switch the camera to download the pictures on the SD card and via the same web server mechanism enable pictures to be ...

How to Teledrive a Modded car from anywhere in the World over the Internet  How to remotely drive a vehicle from anywhere in the world? Teledrive ie remote drive is a useful idea. One application: UAVs are flown around the world for surveillance while sitting in the comfort of a terrestrial ground station. Another example is to drive a Truck over the network like here:  Einride Remote Drive Prototype   Customising a commercial EV even though a very exciting exercise has its own challenges and timelines. Need to understand the mechanical angle and also the hardware angle, say identify relevant motors, torques and install and check they perform optimally. Will have to be iterated multiple times. A better option would be to try all the experiments on a small scale, say on a toy. Something similar to the Flight of Phoenix (2004)  movie. There have been many mods of expensive RC car like the Traxxas car.  Traxxas RC cars But these are expensive and hence a low cost s...