Summary of LCD Module Control over IR Link using PIC16F690
This project implements LCD control over an IR link using PIC16F690 microcontrollers, HSDL-1100 IR transceivers, and a KS070B LCD. It demonstrates serial communication between two PICs with a 16-bit packet protocol supporting up to 32 device addresses and basic error detection via two inverse parity bits. Packets distinguish command versus data bytes and are transmitted as sequences of short IR pulses to drive the LCD remotely.
Parts used in the LCD Module Control over IR Link using PIC16F690:
- PIC16F690 microcontrollers (two units)
- HSDL-1100 IR transceivers
- KS070B LCD display module
- Power supply (suitable for PIC and LCD)
- Supporting passive components (resistors, capacitors)
- Wiring and connectors
- Optional prototyping board or PCB
Recently I got my hands on a couple of HSDL-1100 based IR transceivers and a KS070B LCD display module. This was a nice opportunity to experiment with three things: (1) controlling an LCD module, (2) serial communication between two PIC microcontrollers, and (3) making this work over an IR link.
Serial protocol supports addressing of up to 32 devices over shared media (IR or direct connection) and have basic error detection (2 inverse parity bits). Packets consist of 16 bits, as given below:
- P0 – inverse parity of all even numbered bits [2-14]
- P1 – inverse parity of all odd numbered bits [3-15]
- Device ID – ID of the target device; LCD responds to ID 00001
- C/D – Code or Data; if “1”, following byte contains command (for example, LCD “CLEAR SCREEN” command); if “0”, following byte contains data (in case of the LCD this would be code of a character to be displayed).
Data is encoded as a sequence of short pulses. The beginning of a data packet is shown below:
For more detail: LCD Module Control over IR Link using PIC16F690
- What microcontroller is used in the project?
Two PIC16F690 microcontrollers are used for serial communication and control. - Which IR transceivers are used for the link?
HSDL-1100 IR transceivers are used for the IR link. - Which LCD module is controlled in this project?
The KS070B LCD display module is used. - How many devices can the serial protocol address?
The serial protocol supports addressing up to 32 devices over the shared media. - What is the packet size in the protocol?
Packets consist of 16 bits. - How does the protocol provide error detection?
Error detection is provided by two inverse parity bits, P0 and P1. - What do the C/D bits indicate?
The C/D bit indicates whether the following byte is a command (1) or data (0) for the LCD. - What device ID does the LCD respond to?
The LCD responds to device ID 00001.
