This circuit works using anything that can transmit serial data and monitor a CTS signal.The controller is a PIC16F84 that uses two lines for serial control. One for serial input and one for DTR/CTS (pin 8 is CTS on a 9 pin connector if you are hooking to a PC). It will take back-to-back updates and doesn’t have jitter.source
Microcontroller
3-wire serial LCD interface for the PIC
If you are developing applications for the PIC, and miss the costly debugging tools, or can’t afford a parallel LCD interface in your design, this serial interface can help printing debug messages and/or reduce the pin count. This version uses a Hitachi HD44780 compatible LCD module in 4-bit mode. The interface is based on the idea of Myke Predko.source
Electronic irrigation controller
This is a simple one-valve irrigation controller made for our greenhouse. The code contains a software real-time clock (RTC) and a multiplexed 8-digit LED display and keyboard you can use in other projects.The operating software is simple, it contains a real-time clock and a day counter. The valve is turned on in regular intervals in the same time.The source code is freely downloadable. This is written for the PIC16F84, but you can easily adapt it to newer controllers like the PIC16F628 source
Serial port controlled infrared transmitter with PICMicro
This is a programmable infrared (remote control) transmitter, which can be controlled from a PC serial port. It is capable of sending many remote control formats, including the Philips RC-5 standard.The controller will accept commands on the serial port. Settings are: 19200 bps, 8 bits, no parity, 1 stopbit, no flow control (XON/XOFF or RTS/CTS). Commands consist of hex coded bytes and must be written on the port as ASCII characters separated by space, terminated by ENTER (ASCII char 0d) source
IR/RF remote control with PIC Microcontroller
This is a general purpose remote control project with using programmable PIC microcontrollers. Schematics are shown for using infrared (IR) or radio (RF) media. If you are not familiar with microcontroller programming, you can use fixed encoder and decoder integrated circuits instead. Well-known such IC-s are Holtek HT-12D, HT-12E and Motorola MC145026, MC145027, MC145028.source