Dilshan R Jayakody’s Web Log

StarPointer is a virtual electronic finderscope for astronomical telescopes. This device works with Stellarium and helps the observer identify objects in the sky.  Prototype version of the StarPointer sensor kit. This unit can be attached to the telescope without modifications and connects with the computer through the USB port. The StarPointer uses a few onboard sensors to determine its angle and position. After obtaining that information, the unit calculates the RA (right ascension ) and DEC (declination) coordinates of the telescope and transfers those details to the Stellarium. The StarPointer builds around the STM32F103C8 microcontroller, ADXL345 3-axis accelerometer , and HMC5883L 3-axis magnetometer . This unit communicates with the PC using the inbuilt USB peripheral of the STM32F103C8 microcontroller. The firmware of the StarPointer is developed using the LibOpenCM3 library and built using GNU ARM Embedded Toolchain . This unit can attach to any astronomical telescope o...

OpenFAT is an open-source FAT file system implementation for embedded systems. The original library is well written and documented. We recently came across this library while looking for a LibOpenCM3 support SD/MMC FAT file system library. At the initial review, we notice that this library does not maintain for the last ten years. Also, it does not provide support to the latest SD card types. After review the latest SD card specifications , we add SD card support to this library and release it with the same license. The updated library is available at the github.com/dilshan/sdfatlib . The testing of this library is carry on a popular STM32F103C8T6 blue pill development board. The suggested wiring layout is given, below. Wiring layout for the test setup. For the above test layout, we use a standard SD card adapter module (which comes without a built-in level-shifter and voltage regulator). Due to the 3.3V support of the STM32F103C8T6 , the wiring layout is straightforward. The CH34...

Simple NTP clock is a maintenance-free clock application developed to work on single-board computers like Raspberry Pi , Orange Pi , etc. This clock application uses the Simple Network Time Protocol (SNTP) to get the time and display it on seven segment display which I designed . This application is designed to work on most of the Linux based systems and had minimum dependencies with system libraries and peripherals. I developed this application to work with Allwinner H2 Plus based Orange Pi Zero board, but this can compile for other platforms without doing any modifications on the source code. NTP clock on Orange Pi Zero. To compile this application issue the following commands: make clean make Parameters related to this application are available at config.json file. This file can be used to specify the NTP server, time zone, and display module port. The source code of this project is available at github.com .

This project is about an open source, USB based, 10 digit seven segment display unit. This unit is specifically designed to work with POS systems and banking applications. Initially, this system is developed to work with PC based systems, and later it was modified to work with other platforms and applications. Final view of the USB seven segment display module To simplify the communication interface this unit is designed to emulate a COM port in the host terminal. Because of this feature, this module can work with many systems without having any additional device driver(s). To extend the scope of this unit, it also comes with an option to switch between " direct mode " and " API mode ". In " direct mode " application or host device can directly send characters to the display unit over the emulated serial communication channel. The " API mode " is intended to provide more extensive features with this unit. All the " API mode ...