Dilshan R Jayakody’s Web Log

YALI ( Yet Another LCD Interface ) is an open-source project to provide a universal interface to drive the popular Hitachi HD44780 LCD controller. This module supports 3.3V and 5V MCUs and hardware development platforms, including Arduino, STM32, PIC, and ESP8266. YALI hardware module. The hardware module of this project consists of a 74HCT08 CMOS AND gate and a 74HC595 8-bit serial-in, parallel-out shift register. This module uses the MP1540 step-up converter to power the LCD unit connected to the system. The module has the jumper to select 3.3V or 5V DC power input.  Bottom side of the YALI hardware module. The YALI library is developed using C and is designed to be easily integrated with any C/C++ embedded toolchain. At the initial design stages, this library was successfully tested with all Arduino development boards, NodeMCU , STM32 Blue Pill , etc. The target system must have three digital output lines with 5V or 3.3V logic levels to interface with the YALI module. As m...

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 ...