ATtiny13 as IR receiver

ATtiny13 as IR receiver

IR controller is everywhere in your home, but you can not control anything. But if you can follow me to make a very cheap PCB with ATtiny13, you can control most equipment in your home. Out of your home? Maybe more interesting.

What's that stuff?

Generally, it's a PCB can receive IR signal from your IR controller, and control other things like light or TV.Just with a relay.

Why ATtiny13?

ATtiny13 is an ATMEL product, AVR family. This chip is very cheap. If your chip is cheap enough, you can use it anywhere you want.

The chip's power:

1. Small: only 8 pin, 6 GPIO

2. Cheap: $0.3

3. Powerful: 1KB Flash, 64 Byte RAM, 64 Byte EEPROM, up to 20MHz clock

4. Save energy: 240 uA @ 1MHz, <1uA @ power-down mode

5. Most important reason: I like it, :-)

How to recognize IR signal?

Most popular IR signal is defined by NEC. First 9ms signal, 4.5ms no signal, and then is 4 byte data, front 2 byte is address, last 2 byte is reverse to each other.

If chip's software, you need State Machine to change state by input signal right now, and put it in 1 bit. Because ATtiny13 only have 64 Byte RAM, so you can not save all voltage one by one. Transform it immediately, you will only need 4 Byte RAM.

Want debug it? ATtiny13 do not have a serial port, so you can write some status to EEPROM, and read it out later. Maybe it's hard, but it's cheap.

Some IR data

My MacRemote's address code is 0x77e1, yours maybe difference. Signal of buttons:

OK=0x3a5d

Vol+=0x505d

Vol-=0x305d

<<=0x905d

>>=0x605d

MENU=0xc05d

>||=0xfa5d

More feature with IR

IR is very useful for control, you can use it transfer serial port with 9600 bps. And you can use anyother device as adapter between IR and other channel, for example your cell phone as adapter communicate with GSM/3G/4G network.

If you are interested with IR, contact me.