Dilshan R Jayakody’s Web Log

When it comes to automation and control systems, there's often a need for multiple digitally controlled output terminals with high-voltage handling capabilities. Many existing modules are bulky, expensive, or require numerous additional components to function. To address this gap, I've developed a fully open-source, USB-controlled 24-channel high-voltage driver. This device provides precise, flexible control in a compact and user-friendly package. The project is open hardware, released under the CERN-OHL-W license, ensuring transparency from hardware schematics to firmware code. The driver module communicates via USB using a simple virtual COM port, eliminating the need for special drivers and complex setups. Prototype version of the module. At the core of the system are three TPIC6B595 shift registers, each supplying eight open-drain outputs that can handle up to 50V and sink currents of up to 150mA per channel. These registers are daisy-chained to achieve a total of 24 ...

In this project, we developed a 5.1-channel analog audio processor using PT2322 IC. PT2322 is an inexpensive analog audio processor introduced by Princeton Technology Corporation . It contains 6-channel individual channel attenuators, a 3-way tone control system for front-end speakers, and a 3D audio simulation system.  Assembled 5.1-channel audio processing board. In this design, we combine PT2322 with Arduino Nano and interface it with PC/embedded computing boards through a USB port. Native GTK UI application provides to control all functions of the PT2322 IC. The Arduino Nano can directly plugin to the PT2322 module. There are three push buttons on the panel itself to control the volume and mute the audio. To reduce the cost and minimize the PCB size, we use both SMD and through-hole-type components in this PCB. The dimension of the PCB is 59mm × 60mm. The PCB of this module can directly order from the PCBWay project page . Using the PCBWay service, you can order high-...

USB Morse Keyer is a microcontroller-based auto keyer project with following features: USB / straight key / iambic key inputs. Support for both standalone and USB operating modes. 64-character USB typeahead buffer and 6-character Morse key typeahead buffer. Support 5, 10, 15 WPM. 6-page message memory. 1W Audio output. Audio and PTT output interfaces. 32 character display  Final view of the USB auto keyer. The USB interface of this unit is designed to work with most of the operating systems. It emulates a virtual serial terminal to transfer keystrokes to the keyer. In most of the operating systems, this interface works without installing any additional device drivers. To submit keystrokes user can use any serial terminal software such as PuTTY , Hyper Terminal , Minicom , etc. This keyer is designed to work with 7V to 16V DC input voltage. The most recommended working voltage is 9V. The bottom side of the USB auto keyer. To reduce the dimension of the P...

HC-06 is a quite popular slave mode Bluetooth module designed for wireless serial communication. This module can pair with PC, mobile phone or with any master mode Bluetooth peripheral. HC-06 Bluetooth module This simple .net framework based application can use to modify the following parameters of the HC-06 Bluetooth module: Bluetooth display name Pair password BAUD rate Parity check type HC-06 Bluetooth module programmer This application communicates with the HC-06 module through COM port. To emulate the COM port using any Windows compatible USB to Serial converter . While at the testing we try the following modules with this application: FTDI FT232 USB to Serial module CH340 USB to Serial module CP2102 USB to Serial module This application is developed using .net framework 4.5 and Visual Studio 2012. All source code and compiled binaries are available to download at https://github.com/dilshan/hc6-config . This application and its source code are distrib...

This post is about experimental USB to 3.3V/5V serial TTL adapter which we build recently to work with both 5V and 3.3V MCUs. This project is mainly based on CH340G seral-USB chip. CH340G is cheap and commonly available serial-USB convert IC and now it's commonly found on Chinese versions of Arduino development boards. FTDI's FT232 is another possible alternative for this kind of project, but we drop it because of its famous device driver base chip locking issues . Also, compare with FT232, CH340G is cheap, commonly available and simple to construct with a minimum number of components. In this module, we incorporate a 5V/3.3V voltage selector switch to avoid interface matching issues due to different voltage levels of mainboard/MCU and serial TTL adapter. A prototype version of CH340 USB to serial adapter. In prototyping stages, we use CH340G with breadboard by using SO-16 to DIP16 adapter and supplied PCB is also based on using the same adapter. Except for CH340G ...

This is demonstration project to control servo motor movement using physical marker and normal video camera. In this project video camera capture the movements of marker and calculate rotation angle based on that. This calculated rotation angle is feed to the servo through small MCU based interfacing unit. In this project video processing and tracking is performed using ARToolkit and controlling of servo is carried out using PIC16F628A microcontroller. RS232 interface is use to communicate between PC and microcontroller. Interfaces in optical servo controlling system This application detects movement of marker on Z axis (yaw) and transforms it into another numerical scale to manipulate the servo motor. Processing application is written using Visual C++ and configured to work on Windows operating system(s). The marker used for this application is needed to be a " square with some symbol " and user can train this system for any compatible marker. As per our tests, st...

In this project we design low cost high performance programmable home security system using few LDR’s as an input sensors. When above sensor(s) get triggered system may dial the user specified phone number (using build-in DTMF generator) and activate the high power audio alarm and lights. All the parameters of DTMF generator, audio alarm and light interface are programmed through the RS232 serial interface. Current firmware of this system presents interactive control system through the RS232 interface. This control system consist with the menu driven configuration options, self tests, system report generators, etc. This system also contain 5W (with 4Ω speaker) audio alarm with three selectable tone configurations, which include Police siren, Fire engine siren and Ambulance siren. This system uses a Microchip’s PIC16F877A as a main controller, LM339 as sensor interface, UM3561 as a tone generator and μPC2002 as a speaker driver (audio amplifier). LM7805, LM7812 and LM317 voltage...