Peter's electronic projects

Learning IR remote control receiver

RC-5 version: 2012/07/15
NEC version: 2015/03/18
designed by Peter JAKAB

NOTE for beginners: PICs are general purpose microcontrollers which have to be programmed before you can use them in the actual circuit! Check out this link to learn more.

description

Control anything with your remote control. This receiver works with RC-5 and NEC format IR remote controls, depending on the firmware used. The receiver has 11 output channels, and each channel can have up to 4 buttons (on, off, toggle, momentary-on) associated with it.

The output types are:

off: turn the associated output channel off
on: turn the associated output channel on
toggle: turn the associated channel output on then off
momentary-on: turn the associated channel on for the time the button is being pressed

teaching buttons

The firmware for the receiver already contains a default button layout ready to test operation, so you can skip this section for the first time. The default button associations for the RC-5 version are:

channel	toggle	off	on	momentary-on
#0				0
#1				1
#2				2
#3				3
#4				4
#5	5
#6	6
#7	7
#8	8
#9	9
#10		VOL -	VOL +

To enter programming mode, setup the switches as this: B0:ON, B1, B2, B3: OFF then turn on the circuit.
To erase all button associations, setup the switches as this: B0, B1, B2, B3: ON then turn on and off the circuit.

operation	B0	B1	B2	B3
enter programming mode at power-on	ON	OFF	OFF	OFF
erase all button associations at power-on	ON	ON	ON	ON

After entering the programming mode, switches B1-B3 select the operating mode of the remote control button being learnt.

operation	B1	B2	B3
clear the next button pressed from memory	ON	OFF	ON
the next button pressed turns the selected output channel OFF	OFF	OFF	ON
the next button pressed turns the selected output channel ON	OFF	ON	OFF
the next button pressed toggles the selected output channel	OFF	ON	ON
the next button pressed turns the selected output channel ON for the time being pressed	ON	OFF	OFF

Setup the switches B1-B3 according to the desired output type, then select the associated output channel with switches B4-B7.

channel	B4	B5	B6	B7
#0	OFF	OFF	OFF	OFF
#1	ON	OFF	OFF	OFF
#2	OFF	ON	OFF	OFF
#3	ON	ON	OFF	OFF
#4	OFF	OFF	ON	OFF
#5	ON	OFF	ON	OFF
#6	OFF	ON	ON	OFF
#7	ON	ON	ON	OFF
#8	OFF	OFF	OFF	ON
#9	ON	OFF	OFF	ON
#10	OFF	ON	OFF	ON

Select the output channel with switches B4-B7, then push a button on the remote control to teach. If the button was learnt successfully, the VALID LED flashes for a moment. If you can't see the LED light up for a moment, the button pressed is already associated to something, and can't be used again. Or, the state of the B1-B7 switches is invalid. If you want to erase a remote control button from the memory, setup the B1-B3 switches as: B1:ON, B2:OFF, B3:ON. Leave B4-B7 switches as is, their state is not significant. Then push the remote control button to be erased. The VALID LED flashes for a moment, signaling the button is erased.

When you have finished programming, setup B0-B7 all OFF, and turn off the circuit.

An example programming session:

setup the swiches as: B0:ON, B1:ON, B2:ON, B3:ON
turn off and then on the circuit - all button associations are erased
setup the switches as: B1: ON, B2: OFF, B3: OFF - momentary-on output type is selected
setup the switches as: B4: OFF, B5: OFF, B6: OFF, B7: OFF - channel #0 is selected
push button 0 on the remote control - the VALID LED is lit for a moment, signaling successful learning
setup the switches as B4: ON, B5: OFF, B6: OFF, B7: OFF - channel #1 is selected
push button 0 on the remote control - nothing happens, as this button is already associated to something, and can't be used
push button 1 on the remote control - the VALID LED is lit for a moment, signaling successful learning
setup the switches as B4: OFF, B5: ON, B6: OFF, B7: OFF - channel #2 is selected
push button 2 on the remote control - the VALID LED is lit for a moment, signaling successful learning
setup the switches as B1: OFF, B2: ON, B3: ON - toggle output type is selected
setup the switches as B4: ON, B5: OFF, B6: ON, B7: OFF - channel #5 is selected
push button 5 on the remote control - the VALID LED is lit for a moment, signaling successful learning
setup the switches as B4: OFF, B5: ON, B6: ON, B7: OFF - channel #6 is selected
push button 6 on the remote control - the VALID LED is lit for a moment, signaling successful learning
setup the switches as B4: ON, B5: ON, B6: ON, B7: OFF - channel #7 is selected
push button 7 on the remote control - the VALID LED is lit for a moment, signaling successful learning
setup the switches as B1: ON, B2: OFF, B3: ON - button erase is selected
push button 2 on the remote control - the VALID LED is lit for a moment, signaling successful erase
push button 7 on the remote control - the VALID LED is lit for a moment, signaling successful erase
setup the switches as B1: OFF, B2: ON, B3: OFF - turn on output channel type is selected
setup the switches as B4: OFF, B5: ON, B6: OFF, B7: ON - channel #10 is selected
push button VOL+ on the remote control - the VALID LED is lit for a moment, signaling successful learning
setup the switches as B1: OFF, B2: OFF, B3: ON - turn off output channel type is selected
push button VOL- on the remote control - the VALID LED is lit for a moment, signaling successful learning

The resulting button layout is:

channel	toggle	off	on	momentary
#0				0
#1				1
#2
#3
#4
#5	5
#6	6
#7
#8
#9
#10		VOL -	VOL +

operation: decoding

The B0-B7 switches must all be turned OFF to enter normal decoding operation. In this mode, any remote control button learnt will light up the VALID_LED for the duration the button is pressed. Output channel states will change according to the type setup learnt.

firmware

Download the source code and compiled HEX firmware

for RC-5 format remotes
for NEC format remotes

The HEX file is ready to program to the PIC microcontroller. If you want to modify and compile the code for yourself, please create a linked project. Read more here

hardware

Connect the circuit to a 12VDC, min. 500mA output power supply. Output should be able to supply enough current when all the relays are turned on. Relay coils are 12VDC.

learning IR remote control receiver

part list

part	count	description
IC1	1	PIC16F627 or PIC16F627A or PIC16F628 or PIC16F628A - Microchip microcontroller, programmed
IC2	1	LP2950CZ5.0 - voltage regulator, 5VDC output
IC3	1	IR receiver module, recommended part numbers: RC-5 format (36kHz): TSOP1236, TSOP4836, TSOP34836, TSOP39236, TSOP36236 NEC format (38kHz): TSOP4438, TSOP58438 or TSOP75438
C1, C2	2	22pF ceramic capacitor
C3, C5	2	100nF ceramic capacitor
C4	1	4.7uF/6.3V electrolytic capacitor
C6	1	10uF/16V electrolytic capacitor
R1, R13x8, R20-R30	20	220 ohm resistor (1/8 W)
R10, R12	2	10k resistor (1/8 W)
R11	1	100 ohm resistor (1/8 W)
D1-D11	11	1N4004 diode
LED	1	3 mm LED, any color
LED0-LED10	11	3 mm LED, any color
Q1-Q11	11	BS170, BSS138, 2N7002 or similar N-channel MOSFET transistor
RL0-RL10	11	G5LE 12V relay
S1, S2	2	DIL4 piano switch
X1	1	HC49 4MHz crystal