Summary of NEC Protocol IR (Infrared) Remote Control With a Microcontroller
This project details the construction of a custom Infrared Remote Control using the NEC protocol, driven by a microcontroller. The author developed unique code to address frequent requests for a transmitter compatible with specific IR relay boards, offering an alternative to standard commercial remotes. The article explains the technical structure of the NEC protocol, including pulse bursts, spaces, and data bit encoding (logical 0s and 1s), which are essential for transmitting addresses and commands to compatible receivers.
Parts used in the NEC Protocol IR Remote Control:
- NEC protocol based Infrared Transmitter
- NEC Protocol IR receivers
- PIC 12F675 Microcontroller
- IR Remote Control Relay Board
Introduction
This little project will demonstrate how you can build NEC protocol based Infrared Remote Control to use with various NEC Protocol IR receivers.
actually there are lots of projects out there to accomplish this task but i have to write my own code because of too many requests on this IR(infrared) Remote Control Relay Board with PIC 12F675 Microcontroller people keep asking “Where is the Transmitter for this” although you can use any NEC protocol based remote ,but i just wanted to build one by my self. so here it is.
Consumer IR protocols
There are a number of consumer Infrared protocols out there and they have been used for every single purpose possible i guess, like PDA laptops and other consumer appliances. RC-5 & RC-6 by Phillips , RCA are few examples of consumer IR protocols.
There are a number of consumer Infrared protocols out there and they have been used for every single purpose possible i guess, like PDA laptops and other consumer appliances. RC-5 & RC-6 by Phillips , RCA are few examples of consumer IR protocols.
In this demonstration we will stick the to NEC protocol by NEC corporation,
NEC Infrared Protocol
- A 9ms leading pulse burst (16 times the pulse burst length used for a logical data bit)
- A 4.5ms space
- The 8-bit address for the receiving device
- The 8-bit logical inverse of the address
- The 8-bit command
- The 8-bit logical inverse of the command
- Final 562.5µs pulse burst to show end of message transmission.
- Logical ‘0’ – a 562.5µs pulse burst followed by a 562.5µs space, with a total transmit time of 1.125ms
- Logical ‘1’ – a 562.5µs pulse burst followed by a 1.6875ms space, with a total transmit time of 2.25
For more detail: NEC Protocol IR (Infrared) Remote Control With a Microcontroller
- Why did the author write their own code?
The author wrote custom code due to many requests for a transmitter compatible with the IR Remote Control Relay Board using a PIC 12F675 Microcontroller. - What consumer IR protocols are mentioned in the text?
The text mentions RC-5, RC-6 by Phillips, and RCA as examples of consumer IR protocols. - Which protocol does this demonstration stick to?
This demonstration sticks to the NEC protocol by NEC corporation. - How is a logical zero represented in the NEC protocol?
A logical zero is represented by a 562.5µs pulse burst followed by a 562.5µs space, totaling 1.125ms. - How is a logical one represented in the NEC protocol?
A logical one is represented by a 562.5µs pulse burst followed by a 1.6875ms space, totaling 2.25ms. - What components make up the leading pulse burst of the NEC protocol?
The leading pulse burst consists of a 9ms leading pulse burst that is 16 times the length used for a logical data bit. - What follows the 4.5ms space in the message transmission?
The 8-bit address for the receiving device follows the 4.5ms space. - How is the end of message transmission indicated?
The end of message transmission is shown by a final 562.5µs pulse burst.
