need help in Sony S.I.R.C at 20/40 mhz

hi guys

Accroding to the manual of the PBP at 20mhz the resolution of PULSIN is 2uS.
but i cant seems to make it work even at 40mhz . But when i used 12mhz xtal or below it work perfectly.

Is there something im mising here?

i really need to make it work at 20mhz or 40mhz.



here is my code:

Header Var Word ' Header pulse length
Packet Var Word ' 12-bit IR information
P_Val Var Byte ' The bit length 60us = 0, 120us = 1
IR_But Var Byte ' The BUTTON code returned
IR_Dev Var Byte ' The DEVICE code returned
Sony_LP Var Byte ' Temporary loop variable
Green_LED Var PortA.1 ' Assign the red LED to this pin

TRISA = 0
LOW Green_LED

START:

GOSUB IRIN
IF IR_But = 0 THEN HIGH Green_LED

GOTO START

IRIN:
IR_Dev=255:IR_But=255
Pulsin PortB.2,0,Header ' Measure the header length.

If Header < 1000 then Return ' Verify a good header
If Header > 1350 then Return ' If not valid then exit

For Sony_Lp=0 to 11 ' Do 12-bits

Pulsin PortA.2,0,P_Val ' Receive the IR bit pulse
If P_Val >= 450 then ' If it's >= 90 then we've received a 1
Packet.0[Sony_Lp]=1 ' So set the appropriate bit of PACKET
Else
Packet.0[Sony_Lp]=0
Endif
Next

' Split the 7-bit BUTTON code, and the 5-bit DEVICE code

IR_But=Packet & %01111111 ' Mask the 7 BUTTON bits

IR_Dev=(Packet >>7) & %00011111 ' Move down and mask, the 5 DEVICE bits
Return



sorry for my english.

best regards,
ferds

Hi,

PBP defaults to 4 MHz operation of the device. If you are using anything else, you need to define it, or your timings would all be off in proportion.

Regards,

Anand

It may just be a typo but the timings shown in your code are an order of magnitiude out.

SONY Timings are as follows

Header pulse is 2400uS ON 600uS OFF
Logic One is 1200uS ON 600uS OFF
Logic Zero is 600uS ON 600uS OFF

You show a "1" as 120uS and a "0" as 60uS

Remember also that the signal you are receiving will be a modulated 40kHz carrier and you need an IR Receiver Module to give you a demodulated signal which is normally ACTIVE LOW.

Pulsein varies with OSC frequency so ensure that you correctly define the OSC and allow for the fact that at higher frequencies the count for a given pulse length will be greater.

eg as Sony is based on a 600uS timeframe then Pulsin would be

4MHz = 10uS resolution = Count of 60, 120, 240
10MHz = 4uS resolution = Count of 150, 300, 600
20MHz = 2uS resolution = Count of 300, 600, 1200
40MHz = 1uS resolution = Count of 600, 1200, 2400

Use those values as the centre values for your acceptance window eg @ 20MHz 270-330, 540-660, 1080-1320 allowing a 10 percent tollerance.

Hope that helps

Keith

DEFINE LOADER_USED 1
DEFINE OSC 4

DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 24h
DEFINE HSER_SPBRG 12 ' 19200 Bauds

Header Var Word ' Header pulse length
Packet Var Word ' 12-bit IR information
P_Val Var Byte ' The bit length 60us = 0, 120us = 1
IR_But Var Byte ' The BUTTON code returned
IR_Dev Var Byte ' The DEVICE code returned
Sony_LP Var Byte ' Temporary loop variable
Green_LED Var Portb.3 ' Assign the red LED to this pin
IR_bin var word

TRISA = 0
LOW Green_LED

START:

GOSUB IRIN
IF IR_But =255 THEN start

HSEROUT ["IR_But ",DEC IR_But,13,10]
HSEROUT ["IR_Dev ",DEC IR_Dev,13,10]

GOTO START

IRIN:
IR_Dev=255:IR_But=255

Pulsin PortB.0,0,Header ' Measure the header length.

If Header < 216 then Return ' Verify a good header
If Header > 264 then Return ' If not valid then exit

For Sony_Lp=0 to 11 ' Do 12-bits

Pulsin PortB.0,0,P_Val ' Detech 1 Check space pluse ,Receive the IR bit pulse
If P_Val > 100 then ' If it's >= 90 then we've received a 1
'Packet.0[Sony_Lp]=1 ' So set the appropriate bit of PACKET
Packet.0=1
Else
'Packet.0[Sony_Lp]=0
Packet.0=0
Endif


Next

' Split the 7-bit BUTTON code, and the 5-bit DEVICE code

IR_But=Packet & %01111111 ' Mask the 7 BUTTON bits

IR_Dev=(Packet >>7) & %00011111 ' Move down and mask, the 5 DEVICE bits

Return

Work well for sony remote

And now we try to HITACHI remote ,Space(0) type (sony remote , Pulse(1) type)


Still not work ......What i worng

'*** IR decode fro Hitachi remote*********

DEFINE LOADER_USED 1
DEFINE OSC 4
'DEFINE OSC 20

'// For PIC16F62x & A versions
'CMCON = 7 '// Comparators Off
'VRCON = 0 '// Vref Off

DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 24h
DEFINE HSER_SPBRG 12 ' 19200 Bauds

Header Var Word ' Header pulse length
Packet Var Word ' 12-bit IR information
P_Val Var Byte ' The bit length 60us = 0, 120us = 1
IR_But Var Byte ' The BUTTON code returned
IR_Dev Var Byte ' The DEVICE code returned
Sony_LP Var Byte ' Temporary loop variable
Green_LED Var Portb.3 ' Assign the red LED to this pin
IR_bin var word

TRISA = 0
LOW Green_LED

START:

GOSUB IRIN
IF IR_But =255 THEN start

HSEROUT ["Bottom ",DEC IR_But,13,10]
HSEROUT ["Comand ",DEC IR_Dev,13,10]

GOTO START

IRIN:
IR_Dev=255:IR_But=255

Pulsin PortB.0,0,Header ' Measure the header length.

If Header < 704 then Return ' Verify a good header
If Header > 968 then Return ' If not valid then exit
PAUSEUS 240 'wait for header space

For Sony_Lp=0 to 31 ' Do 32-bits

Pulsin PortB.0,1,P_Val ' Detech 1 Check space pluse ,Receive the IR bit pulse
If P_Val > 150 then ' If it's >= 90 then we've received a 1
Packet.0[Sony_Lp]=1 ' So set the appropriate bit of PACKET
Else
Packet.0[Sony_Lp]=0
Endif

Next

' Split the 7-bit BUTTON code, and the 5-bit DEVICE code

'IR_But=Packet & %01111111 ' Mask the 7 BUTTON bits
IR_But=Packet.highbyte
'IR_Dev=(Packet >>7) & %00011111 ' Move down and mask, the 5 DEVICE bits
IR_Dev=Packet.highbyte
Return

Hitachi pluse detail , 32 bit , space type
IR head = 8800(+) , 2200 (-)
1 = 550(+) , 1650 (-)
0 = 550(+) , 550 (-)

Still not work ......What i wrong..

Hi,

Your code shows "DEFINE OSC 4", while your original post suggests you are trying to use a 20MHz crystal; if the crystal is actually 20MHz, change your define accordingly. If on the other hand it is 4 MHz, the define is not really required as PBP defaults to that anyway.

Regards,

Anand