IR Learner? Need ideas

Hi, I am trying to build a program for my 16F676 which can help it learn at least 1 code from any IR transmitter. Two LEDs (red and green) to be connected to my PIC, one button & one IR receiver. When button is pressed PIC should go to the learning mode.
Then while in learning mode someone to press a button on ANY ir remote and PIC will learn that button code. Every time that particular button is pressed, green LED to glow for 1 sec else RED will stay ON.

I have a code I use currently, but it involves me making my own transmitter as well, since I can control pulses coming out from my own transmitter, it is easy to program the receiver to catch those pulses (Thanks to Bruce for his codes on his website).

Code:

PULSIN PORTA.3,0,PULSE_IN '// Read-in start pulse IF (PULSE_IN < 200) OR (PULSE_IN = 0) OR (PULSE_IN > 270) THEN Decode2 '// Less than Start pulse, then keep looking Verify: FOR Index = 0 TO 15 '// Setup to read-in 16 pulses PULSIN PORTA.3,0,IR_PULSE[Index] '// Read 13 low-going pulses on RA.7 NEXT Index '// Loop x times DBYTE = $FF '// Start with all 1's and find each 0 ABYTE = $FF '// Start with all 1's and find each 0 in pattern FOR Index = 0 TO 7 '// Get 8 "data" bits IF IR_PULSE[Index] < 85 THEN DBYTE.0[Index]=0 IF IR_PULSE[Index+8] < 85 THEN ABYTE.0[Index]=0 NEXT Index

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Since now I want to train my PIC to learn any sort of pulse from any sort of transmitter, I am totally confused as to how my PIC will learn that. I have to sync with some start bit to make this happen. But there are so many protocols, that I need a little help to achieve this.

Re: IR Learner? Need ideas

Your approach is far too limited. Some protocols use PulseWidthModulation (PWM), some use PulsePositionModulation (PPM) and some use something entirely different. Also the number of bits in a code can vary from less than 20 to more than 100. Most, but not all, use an extended silence between repeat copies of the code.

My interest has been more with RF than IR but the approach is similar except that most RF receivers are active high while most IR receivers are active low.

Here's some code I use with RF. You'll need to modify it for IR. And it will capture only PWM & PPM codes - there are other protocols.

Code:

'============================RECEIVER============================ 'PIC12F683 @ 8MHz <500 words 'Receives up to 44 bits of PDM/PWM RF with initial lead-in of 2-9mS 'outputs received codes via RS232 @ 9600bps on GPIO.4 (Pin 3) @ __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _PWRTE_ON & _MCLRE_OFF & _BOD_ON & _CP_OFF & _CPD_OFF DEFINE OSC 8 '8 MHz oscillator DEFINE ADC_BITS 8 DEFINE ADC_CLOCK 3 DEFINE ADC_SAMPLEUS 25 DEFINE DEBUG_REG GPIO DEFINE DEBUG_BIT 4 'GPIO.4 (Pin 3) DEFINE DEBUGIN_BIT 3 'GPIO.3 (Pin 4) DEFINE DEBUG_MODE 1 'Inverted logic DEFINE DEBUG_BAUD 9600 Symbol Capture=PIR1.2 'CCP1 capture flag Symbol PinChng=INTCON.0 'InterruptOnChange Symbol RS232=GPIO.3 'GPIO.3 (Pin 2) Symbol RS485=GPIO.0 'GPIO.0 (Pin 6) RF VAR byte[6] RS VAR byte[6] cfg VAR byte[5] ID VAR byte pw VAR word i VAR byte bits VAR byte bytes VAR byte sof VAR word 'start of frame minSOF VAR word 'minimum start pulse (1900-8500 ~1.9mS-8.5mS) minBits VAR byte adc VAR byte id VAR byte module VAR byte addr VAR byte rssi VAR word 'received signal strength indicator DATA $01,$FE,$6C,$07,$0E,$01 'EEPROM module,id,minSOF (1900),minBits (14),adc OSCCON = %01110001 'INT HF OSC 8MHz WHILE OSCCON.3>0:WEND 'OSC startup timeout WHILE OSCCON.2=0:WEND 'INT HF OSC stable CMCON0 =%00000111 'comparators off TRISIO =%00101110 'make GPIO.0,4 outputs GPIO =%00000000 'make GPIO.0,4 LOW ANSEL =%00000010 'make GPIO.1 analog ADCON0.7=1 'right justify ADC result for 10-bit IOC =%00001001 'IOC Pins enabled INTCON =%00000000 'disable interrupts READ 0,module DEBUG DEC module,32 READ 1,id DEBUG DEC id,32 READ 2,minSOF.LowByte READ 3,minSOF.HighByte DEBUG DEC minSOF,32 READ 4,minBits DEBUG DEC minBits,32 READ 5,adc DEBUG DEC adc,10,13 init: RF[0]=0:RF[1]=0:RF[2]=0:RF[3]=0:RF[4]=0:RF[5]=0 CCP1CON=%00000101:Capture=0 'capture rising edge While !Capture 'wait for rising edge Wend TMR1H=0:TMR1L=0:T1CON=%00010000 'prescale=2, tick=1uS ADCIN 1, rssi 'read pulse amplitude CCP1CON=0:Capture=0 'capture falling edge While !Capture 'wait for falling edge Wend sof.HighByte=CCPR1H:sof.LowByte=CCPR1L If (sof<minSOF) Then init '<min so abort If (sof>9600) Then init '>max so abort ADCIN 1, i 'read space amplitude If (i<rssi) Then rssi=rssi-i Else rssi=i-rssi EndIf CCP1CON=%00000101 'capture rising edge bits=0:Capture=0:INTCON.2=0 While !Capture 'wait for rising edge Wend Repeat TMR1H=0:TMR1L=0:T1CON=%00010000 'prescale=2, tick=1uS TMR0=100 'overflow 156*16=2496uS (100+156=256) OPTION_REG=%10000100:Capture=0 'TMR0 prescale=16 While !Capture 'wait rising edge If INTCON.2=1 Then break 'TMR0 overflow (GAP>2.5mS) Wend pw.HighByte=CCPR1H:pw.LowByte=CCPR1L If (pw<850) Then init '<0.85mS so abort If (pw>1300) Then '>1.3mS RF.0(i)=1 'set bit EndIf i=i+1 Until (i>43) break: If (bits<>20) Then bits=i+1 EndIf If (bits<minBits) Then init bytes=(bits)/8 If ((bits)//8>0) Then bytes=bytes+1 EndIf Debug bits For i = 0 to bytes Debug ihex2 RF[i] RS[i]=RF[i] Next DEBUG ihex2 (sof/40) If (adc>0) Then DEBUG ihex2 (rssi>>2) EndIf debug 13,10 GoTo init End

A more generalized method that can capture any protocol uses a bit array and samples the input at 25-50µS intervals, setting a bit when the sample is high. This gives you an image of the code with the resolution depending on the sample rate.

You might find some of the links on my web page useful.
http://davehouston.org/ir-rf_fundamentals.htm
http://davehouston.org/learn.htm
http://davehouston.org/RFTipsTricks.htm

Re: IR Learner? Need ideas

Quote:

Originally Posted by dhouston

A more generalized method that can capture any protocol uses a bit array and samples the input at 25-50µS intervals, setting a bit when the sample is high. This gives you an image of the code with the resolution depending on the sample rate.

Cheers Dave for the reply. I am still learning this stuff at my pace, can you please elaborate your point with few lines of code for my better understanding.

Re: IR Learner? Need ideas

As my interest has been with RF, with PWM & PPM and with defined protocols, I've never needed to use the generalized method so I have no code. Also, most PICs (all but PIC18) are limited to a maximum array size of 256 bits. If we sample every 50µS (0.00005 secs) 256 bits can only record 0.00005x256=0.0128 secs or 12.8mS which is less than 1/10 the length of some IR codes.

This method was used by dedicated IR devices such as Slink-e and Ocelot which had more powerful processors and much more memory (external to the processor).

Re: IR Learner? Need ideas

Thanks for the info Dave.

I have also gone through a lot of info about this today. I will narrow down my selection to only accept codes from 3 protocols only SIRC, NEC & RC5.

Can anyone advice on how to catch and write routines to save a particular button value coming from any of the remote operating on either of the above protocols. ( I am using 16F676)
Thanks a lot in advance

Re: IR Learner? Need ideas

The RF code I posted earlier in the thread will handle SIRC & NEC although you will need to modify it because IR is active low and it is expecting active high. You want to catch falling edges rather than rising edges.

RC5 is harder - there is no pronounced difference in its start sequence. IIRC Bruce Reynolds has code for it. He may have posted it here or it may be on his website.
http://www.rentron.com/

This site is also quite helpful.
http://www.sbprojects.com/knowledge/ir/ir.htm

Re: IR Learner? Need ideas

I use the sony protocol. I think that is more easy to learning.
You can use some universal remote control (with sony protocol) to test and to learn.
My sample to help:

@ DEVICE pic16F628a, INTRC_OSC_NOCLKOUT ' System Clock Options
@ DEVICE pic16F628a, WDT_OFF ' Watchdog Timer
@ DEVICE pic16F628a, PWRT_OFF ' Power-On Timer
@ DEVICE pic16F628a, BOD_OFF ' Brown-Out Detect
@ DEVICE pic16F628a, MCLR_ON ' Master Clear Options (External)
@ DEVICE pic16F628a, LVP_OFF ' Low-Voltage Programming
@ DEVICE pic16F628a, CPD_OFF ' Data Memory Code Protect
@ DEVICE pic16F628a, PROTECT_OFF ' Program Code Protection
DEFINE OSC 4
'Definição das variáveis e declarações
INCLUDE "bs1defs.bas" 'inclui arquivo p/ compatibilizar com BS1
'p/entender as variáveis b0...b3, w0...w6 e bit0...bit13
CMCON = 7 'DEFINE PORTA COMO DIGITAL (COMPARADORES ANALÓGICOS:OFF)
symbol ir = PORTB.7 'entrada do sinal de IR
SYMBOL LED = PORTB.4
SYMBOL RELE = PORTB.0
TRISB = %10000000

'-------------------------------------------------------------------------------
PORTB = 0
LED = 1: PAUSE 100
'-------------------------------------------------------------------------------
'rotina principal
LOOP_1:
pulsin ir,0,w0 'wait start bit
if w0 < 200 then LOOP_1 'start bit is > 200
pause 20 'jump first sent
pulsin ir,0,b0 'wait 2º start bit
pulsin ir,0,b1
pulsin ir,0,b2 'read each bit from IR code
pulsin ir,0,b3
pulsin ir,0,b4
pulsin ir,0,b5
pulsin ir,0,b6
pulsin ir,0,b7

bit0=b1/96 ' LSB
bit1=b2/96
bit2=b3/96
bit3=b4/96
bit4=b5/96
bit5=b6/96
bit6=b7/96 ' MSB
bit7=0

if b0=21 then COMANDO 'test the values of your control
GOTO LOOP_1

COMANDO:
RELE = 1
LED = 1
PAUSE 500
RELE = 0
LED = 0
GOTO LOOP_1

'-------------------------------------------------------------------------------
end

Other article to learning from Experimenting_pbp.pdf:
"
Sony, infrared remote control Receiver
There are three main protocols used for the transmission and reception
of infrared signals . RC5, which is used by Philips, Rec-80, which is used
by Panasonic, and the Sony format (SIRCS), which will be described
here. Each form of infrared signalling has one thing in common, that is
the use of modulated infrared light. Modulation is used to enable a
certain amount of immunity from ambient light sources, especially
fluorescent lighting. The frequency of modulation varies from 36kHz to
40kHz, depending on the manufacturer . An infrared detector is required
to convert this modulated light into a digital signal . These are readily
available in just about every TV, VCR, and satellite receiver made within
the past 20 years . The type used for these series of experiments is the
Siemens SFH506-38, (unfortunately it's now out of production, but the
alternatives are the SFH5110 or the LT-1059) . These are small three
terminal devices that have a centre frequency of around 38kHz .
However, just about any type may be substituted, the only difference that
will be apparent will be a slight lack of range .
For the Sony protocol, the remote sends a start bit, sometimes called an
AGC pulse, that is 2.4ms in length . This allows the receiver to
synchronize, and adjust its automatic gain control, this occurs inside the
infrared detector module. After the start bit, the remote sends a series of
pulses . A 600us pulse represents a zero, and a 1200us pulse represents
a one, there is a 600us gap between each pulse. Not all manufacturers
stick stringently to these timings, so we will consider them as
approximates. All of these pulses build up a 12-bit serial signal called a
packet . This comprises of a 7-bit button value (the remote button
pressed), and a 5-bit device value (TV, VCR, etc) . The serial signal is
transmitted with the least significant bit sent first . "

Re: IR Learner? Need ideas

Have somebody doing something like this (ir-remote, ir-learner, ir-repeater) but using RC10 protocol ?

Getting there...

I have been reading a good example of somewhat what I need (requires modifications) at this page: http://home.citycable.ch/flotulopex/...I_Frames_e.htm

Few questions have arisen in my mind about this code:
1) Why in this code IRM_OUT is an output but being used as an input?

Code:

IRM_Out VAR PORTA.1 'IR RX Module VDD (OUT) TRISA = %00000000 'Set Input/Output IRM_Out = 1 'set port HIGH WHILE IRM_Out = 1 : WEND 'Wait here until a LOW signal is incoming FOR Ctr_A = 1 TO Max_Bit TMR1H = 0 'Reset Timer TMR1L = 0 'Reset Timer T1CON.0 = 1 'Start Timer WHILE IRM_Out = 0 : WEND 'stay here as long as input signal is LOW T1CON.0 = 0 'Stop Timer V_Tmr.LowByte = TMR1L ' \ V_Tmr.HighByte = TMR1H ' > Store data to LOW_BIT var L_Bit[Ctr_A] = V_Tmr ' / TMR1H = 0 'Reset Timer TMR1L = 0 'Reset Timer T1CON.0 = 1 'Start Timer WHILE IRM_Out = 1 : WEND 'stay here as long as input signal is HIGH T1CON.0 = 0 'Stop Timer V_Tmr.LowByte = TMR1L ' \ V_Tmr.HighByte = TMR1H ' > Store data to HIGH_BIT var H_Bit[Ctr_A] = V_Tmr ' / NEXT Ctr_A C_Led = 0 PAUSE 1000 'wait before continue

2) It is declared that 'factor is a constant =0', then what does this routine do?

Code:

'______________________________________________________________ ' Factorise (time compensation due to BASIC operations latency) FOR Ctr_A = 1 TO Max_Bit IF L_Bit[Ctr_A] >= Factor THEN L_Bit[Ctr_A] = L_Bit[Ctr_A] + Factor IF H_Bit[Ctr_A] >= Factor THEN H_Bit[Ctr_A] = H_Bit[Ctr_A] + Factor NEXT Ctr_A

3) Also it will be much appreciated if someone can explain the following three routines as well, as this purpose is not clear to me

Code:

'_______________________________________________ ' Rescale values (according to acquiring method???) FOR Ctr_A = 1 TO Max_Bit IF L_Bit[Ctr_A] > 0 THEN L_Bit[Ctr_A] = L_Bit[Ctr_A]/2 IF H_Bit[Ctr_A] > 0 THEN H_Bit[Ctr_A] = H_Bit[Ctr_A]/2 NEXT Ctr_A '______________________________________ ' Find the longest H_Bit = interval bit ' This to determine how many bits in pattern FOR Ctr_A = 1 TO Max_Bit IF H_Bit[Ctr_A] > Itv_Bit THEN Itv_Bit = (H_Bit[Ctr_A] + 100) 'store the highest H_Bit value in Itv_Bit Bit_Cnt = Ctr_A 'is the count of bits in the original pattern --- How can bit_cnt count the bits in the original pattern if it only enters this loop if H_Bit[Ctr_A] > Itv_Bit ENDIF NEXT Ctr_A '___________________________________________________ ' Replace all "after pattern" bits with value "zero" FOR Ctr_A = (Bit_Cnt + 1) TO Max_Bit L_Bit[Ctr_A] = 0 H_Bit[Ctr_A] = 0 NEXT Ctr_A

Re: IR Learner? Need ideas

Anyone there???

1 Attachment(s)

Re: IR Learner? Need ideas

It looks like he named it IRM_out, because it is the output of the infra red sensor, so an input on the PIC.

Not sure why he is setting it high, and I don't see it ever set to input.

Have you thought about emailing the author?

IRM_VDD VAR PORTA.0 'IR RX Module Out (VCC)
IRM_Out VAR PORTA.1 'IR RX Module VDD (OUT)

Attachment 5329

Re: IR Learner? Need ideas

Quote:

Originally Posted by scalerobotics

It looks like he named it IRM_out, because it is the output of the infra red sensor, so an input on the PIC.

Thanks for the reply.

If it is an input to the PIC then why the TrisA register is set for it to be an output?

Re: IR Learner? Need ideas

Quote:

Originally Posted by Megahertz

Thanks for the reply.

If it is an input to the PIC then why the TrisA register is set for it to be an output?

Yes, I am with you, confused. Have you tried emailing the author, Flutoloplex?

Re: IR Learner? Need ideas

Yes I did, but seems the author is a very busy man, so I believe experts here will be able to help me on this topic.

Re: IR Learner? Need ideas

I Think that if he used a IR module, then just go work if TRISA.1 = 1, as input!

Pimentel

Re: IR Learner? Need ideas

Quote:

Originally Posted by Pimentel

I Think that if he used a IR module, then just go work if TRISA.1 = 1, as input!

Pimentel

That could be fine if I just want to copy and replicate the code. But I am in a process to understand it fully. Making it input will settle question number 1 in my post above, but still looking for explanation on 2 & 3.

Re: IR Learner? Need ideas

Hi there,

I've been working on some other things these last months so no much time for this forum left :-(

I'll come back with answers shortly.

Some answers

I haven't been working on this project for months so sorry for not answering earlier.

I have updated my webpage because there were still pieces of code or comments that I left during the developpement phase; they have been now removed. Current REMI version is v2-1-2-5.

As already answered

Quote:

Originally Posted by scalerobotics

It looks like he named it IRM_out, because it is the output of the infra red sensor, so an input on the PIC.

So correct reading is:
IRM_VDD VAR PORTA.0 'IR RX Module's VDD
IRM_Out VAR PORTA.1 'IR RX Module's OUT

Quote:

Originally Posted by Megahertz

Why in this code IRM_OUT is an output but being used as an input?

For any (to me) unknown reason, there is no need to declare this port as an Input... and it works. I'm always taking care not set ports as inputs to avoid any external noise and while doing this project, I accidentaly noticed that it works like this so I didn't change it up to now.

The port IRM_Out = 1 because the IR Module idles HIGH. Not setting this port to HIGH will make the LEARN: routine start immediately - not waiting for a real incomming signal.

Quote:

Originally Posted by Megahertz

It is declared that 'factor is a constant =0', then what does this routine do?

"Factorise (time compensation due to BASIC operations latency)". Before using TIMER method to count the elapsed time within a pulse, I used PUSLIN & RCTIME. But PULSIN & RCTIME have a lower accuracy than counting cycles like I do it now.

Previous LEARN routine using PULSIN & RCTIME:

Code:

LEARN: PULSIN IRM_Out, 0, l_Bit[0] 'wait for first Low pulse to start recording TOGGLE led0 IF l_Bit[0] = 0 THEN LEARN: Led0 = 1 RCTIME IRM_Out, 1, h_Bit[0] 'get first High pulse from IR Module FOR Ctr_A = 1 TO (Max_Bit - 1) RCTIME IRM_Out, 0, l_Bit[Ctr_A] 'get Low pulse (1 to 38) from IR Module RCTIME IRM_Out, 1, h_Bit[Ctr_A] 'get High pulse (1 to 38) from IR Module NEXT Ctr_A RCTIME IRM_Out, 0, l_bit[Max_Bit] 'get last Low pulse from IR Module RCTIME IRM_Out, 1, H_bit[Max_Bit] 'get last High pulse from IR Module Led0 = 0 PAUSE 1000 'wait before continue

Quote:

Originally Posted by Megahertz

Also it will be much appreciated if someone can explain the following three routines as well, as this purpose is not clear to me

"Rescale values" is ment to make the the result stored in the L_Bit and H_Bit variables equal to real time according to the oscillator used (4, 8 or 20MHz).

"Find the longest H_Bit" is ment to make the full signal pattern repeatable (next version of REMI) but also to cleanup and trim the freshly learned pattern. In LEARNING mode, one sends the command from the original remote continiously until REMI has stored 40 bits. I admit that REMI will always start learning the very first bit of the transmitted pattern. Since the original remote may send the command repetitively, REMI needs to find whitch bit is the longest that this could be most likely the "separator" of a pattern.

"Replace all 'after pattern' bits with value 'zero'" is an optional routine to check the µC's memory. It helped me to have a better view of what had been programmed in the PIC during debug. This routine can be omitted.

HTH

Re: Some answers

Quote:

Originally Posted by flotulopex

The port IRM_Out = 1 because the IR Module idles HIGH. Not setting this port to HIGH will make the LEARN: routine start immediately - not waiting for a real incomming signal.

I believe most of the IR receiver modules are open drain or open collector. They have a pullup to Vdd and are pulled low by the presence of IR. This also pulls the PIC pin low.