SERIN2 – SEROUT2 and Manchester mistake.

[RCtech]

Hello, i'm trying to send some datas over wireless network from a pic to another one.
For the explanation, pic sender is PICTX and the other is PICRX.

My pics are 12F683 both.

The code sent by the PICTX seems to be okay

Example : If PICTX send the letter " d " in Manchester style over the 433Mhz network, i can read 01 10 10 01 01 10 01 01 on the input pin of PICRX.
Okay but not perfect because i haven't work enough to send the WakeUp string in Manchester style….

This is the code i use for the PICTX :

'---------- Begining

@ device PIC12F683, intrc_osc_noclkout, wdt_off, pwrt_on, mclr_off, protect_off, bod_on
OSCCON = %01110000
DEFINE OSC 8
ansel = 0
cmcon0 = 7
trisio = %000011
INCLUDE "modedefs.bas"
SYMBOL TRANSMISSION = GPIO.2
DEFINE CHAR_PACING 100

LOW TRANSMISSION
Clear
Pause 200

'---------- End of header and now here are the variables

CounterA var Byte
MyDataIn var Byte
ManchesterWord var Word[6]

'---------- End of variables and now, here is the heart

MyDataIn = "d"
GOSUB EncodeManchester
serout2 TRANSMISSION, 16468, [$55,$55,$55,$aa,IBIN16 Manchesterword,13,10]
END

'----------Manchester Encoding

EncodeManchester:
ManchesterWord=0
For CounterA=0 to 7
If MyDataIn.0=0 then
ManchesterWord.14=1
else
ManchesterWord.15=1
endif
If CounterA<7 then ManchesterWord=ManchesterWord>>2
MyDataIn=MyDataIn>>1
Next CounterA
Return
'EOF
'-------------

Well, now, let's talk about my PICRX.
I did a mistake into my code but i don't find wich...

I'm not able to decode my manchester words.

This is the code i use for PICRX:

@ device PIC12F683, intrc_osc_noclkout, wdt_off, pwrt_off, mclr_off, protect_off, bod_on
'----

OSCCON = %01110000
DEFINE OSC 8
ansel = 0
cmcon0 = 7
'----
trisio = %001000 ' Input pin is GPIO 3

INCLUDE "modedefs.bas"

LED VAR GPIO.0
RECEPTION VAR GPIO.3
INFO VAR GPIO.2
CounterA var Byte
ErrorFlag var Bit
WakeUp var Byte
MyDataOut var Byte
ManchesterWord var WORD[6]

Clear
Low LED
LOW INFO
FLAG = 1
Pause 1000

'----

Wait55:
SERIN RECEPTION, n9600, WakeUp
If WakeUp = $55 Then
SERIN RECEPTION, n9600, WakeUp
If WakeUp = $55 Then
SERIN RECEPTION, n9600, WakeUp
If WakeUp = $55 Then
SERIN RECEPTION, n9600, WakeUp
If WakeUp = $aa Then
goto Receive
ENDIF
ENDIF
endif
endif
Goto Wait55
END

'----------

Receive:
SERIN2 RECEPTION, 16468, [ManchesterWord] ' MY ERROR IS HERE I THINK!!
serout2 INFO, 16468, ["This is ManchesterWord : ",IBIN16 ManchesterWord,13,10]
GOSUB DecodeManchester
IF ERRORFLAG THEN
serout INFO, N9600, ["Error !",13,10]
Pause 300
goto Wait55
ENDIF
serout INFO, N9600, ["Value is Okay. (",MyDataOut,")",13,10]
GOSUB Action
GOTO Wait55

'----------

Action :
If (MyDataOut = "c") Then
High LED
Pause 1000
Low Led
Endif
Return

'----------

DecodeManchester:
ErrorFlag=0
For CounterA=0 to 7
If ManchesterWord.1=0 then
MyDataOut.7=0
If ManchesterWord.0=0 then ErrorFlag=1
else
MyDataOut.7=1
If ManchesterWord.0=1 then ErrorFlag=1
endif
ManchesterWord=ManchesterWord>>2
If CounterA<7 then MyDataOut=MyDataOut>>1
Next CounterA
Return

'EOF
'-----------------------


I’m sure it’s a stupid error but i’ve tried many things and i didn’t found.
Any help ?

Thanx a lot.
Lyd.

[mackrackit]

I looked at you code and see that you are using the internal OSC, I would not spend much time de-bugging until these are changed to externals.

99.99% of the time internal OSC are not reliable enough for serial com.

Go with a "resonator" the kind with three pins, and built in caps.

[RCtech]

Thanx mackrackit i know what you say but my problem is not here because, if i don't use the Manchester Encoding/Decoding, it work like a charm, event at 9.6Kbps (i'm glad to saw that).

When i transmit in "clear mode" everything is good.

My error is here :

SERIN2 RECEPTION, 16468, [ManchesterWord]

Because ManchesterWord is double sized than normal byte.
I've tried with SERIN2 RECEPTION, 16468, [STR...

but it's impossible because ManchesterWord is "VAR WORD".

Because i'm just beginner with serin / serout, i don't know all the tips and there is probably one wich can do the rest.

(and sorry for my bad English language, mine is French)
Lyd.

[mackrackit]

This is my best guess, but I am not sure as I do not see anything else.

Where you have IBIN16 , try not using the I. This adds an extra character to the 16 digit string. Worth a quick try?

[Kamikaze47]

This should do it:

SERIN2 RECEPTION, 16468, [ManchesterWord.Byte0,ManchesterWord.Byte1]

[Bruce]

IBIN16 is sending % followed by 16 bytes of data. Not just 16-bits. This produces an
ASCII 0 or 1 for each bit in the word.

Try something like;

serout2 TRANSMISSION,16468,[$55,$55,$55,$aa,Manchesterword.LowByte,Manchesterword.HighByte]

On the receiving end, try something like;

SERIN2 RECEPTION, 16468, [WAIT($aa),ManchesterWord.LowByte,ManchesterWord.HighByte]

This way SERIN2 on the receiving end simply ignores your $55 and waits for $aa before the
16-bit data packet.

[RCtech]

Well i've just done a test :

This is what i send: 0110100101100101
This is what i get on the RXPIC input pin named RECEPTION and connected to the RF 433Mhz circuit: 0110100101100101

You can see it's the same datas.

Now, if i do
SERIN2 RECEPTION, 16468, [ManchesterWord]
SEROUT2 INFO, 16468, [BIN16 ManchesterWord,13,10]

This is what i get on the RXPIC pin named INFO : 0000000000100101

So my error is a pure coding mistake, not RF.

Thanx for you help.

[RCtech]

IBIN16 is sending % followed by 16 bytes of data. Not just 16-bits. This produces an
ASCII 0 or 1 for each bit in the word.

Try something like .../...

Well, it's fantastic, you just turned my simple remote to remote-control ;O)

Yes, your solution works fine.

Many thanx all for your fast replies.

Lyd.

[RCtech]

This should do it:

SERIN2 RECEPTION, 16468, [ManchesterWord.Byte0,ManchesterWord.Byte1]

Yes, it' s the same code as bruce just posted too.
I just need to modify my serout on TXPIC too.

Nice to saw all your replies.

Lyd.