Software uart end

[Marcoos]

Sorry, but it fate of
I entered the serial software and everything seemed to work fine.
But I realized today that if I do not send first one to use the routine in the program the first byte data is corrupted.
The defect was masked by the panel on the pc that automatically discarded the data, but using the serial terminal with the defect is highlighted.
The serial works in slave mode.

#chip tiny44,1
#config osc = int

'Impostazioni RS232
'------------------------------------------------------------------------------

#define SendAHigh Set PORTA.5 Off
#define SendALow Set PORTA.5 On
#define RecAHigh PORTA.6 Off
#define RecALow PORTA.6 On

Dir PORTA.5 Out     'TX232
Dir PORTA.6 In      'RX232

InitSer 1, r300, 1+WaitForStart, 8, 1, none, invert
StartLine = "z"  ' per inizio linea
'------------------------------------------------------------------------------
'mem

Dim StartLine, test1,test2, T1, as byte

'Create buffer variables to store 232 received messages
Dim Buffer As String
BufferSize = 5

SerSend 1, "b"  'pulizia trasm?????????? if not, don't run!!!!
' Loop principale
do
        call SerGest
        wait 500 us
Loop

end

Sub SerGest
    TempSer=0
    SerReceive 1, TempSer
    if TempSer= StartLine then
        T1=1
        for T1=1 to 4
        SerReceive 1, Buffer(T1)
'        SerSend 1, Buffer(T1)   echo for test
        Next
        wait 5 ms
        SerSend 1, StartLine
        T1=1
        for T1=1 to 4
        SerSend 1, Buffer(T1)
        Next
    End if
End sub

[Marcoos]

software uart send.....!!!
Bye

[Anobium]

This may be hard to diagnose.

From my knowledge and experience.

• 'Invert' baud rate idles low, with data pulse going high.

• 'True' baud rate idles high, with data pulses going low. When using a True baud rate
  the very first byte may become corrupt if the output pin was low before the SerSend
  command (the pin will be automatically left high after the SerSend command). To
  avoid this issue place the line high (via a High command’) a few milliseconds
  before the very first SerSend command.

So, using the same principle, I think you have the signals the wrong way around. I would try as below

#define SendAHigh Set PORTA.5 On
#define SendALow Set PORTA.5 Off

I stand to be corrected but remote serial diagnosis is tough.

[Anobium]

Or, leave the SerSend 1, "b" 'pulizia trasm because it seems to work. :-)

:-)

[Marcoos]

Sorry but maybe I have not explained clearly, is quite complicated.
The polarity of the pin is correct, in fact once the match, the serial is working properly, I have zero errors after hours, the problem is only the first send of the sersend, and is also easily be masked, however, remains.
I have an idea, reading your response, but when They come declared the bits for the serial, what state they were before?
who initializes the pins to the correct level?
Tomorrow if I can do the tests.
good night, Marco

[Marcoos]

Hi
I havn't see your last post, yes it work, but tomorrow I want do the test :-)

[Marcoos]

Hello
I Can now confirm the problem is on the output level initialization, this run ok!!!

'Impostazioni RS232
'------------------------------------------------------------------------------

#define SendAHigh Set PORTA.5 Off
#define SendALow Set PORTA.5 On
#define RecAHigh PORTA.6 Off
#define RecALow PORTA.6 On
Set PORTA.5 On  ' set iniziale tx for the right level
Dir PORTA.5 Out     'TX232
Dir PORTA.6 In      'RX232

InitSer 1, r300, 1+WaitForStart, 8, 1, none, invert

if the output level is not initialized correctly, in line with the choices of initialization 232, the first character in the output will be wrong.
Sorry, but I do not have the capacity to do so, but I think based on the When initialization file 232 software should set the appropriate level for its operation, is not it? tell me, thanks, Marco

[Anobium]

Very good news.

I like the idea of initialisation setting the appropriate output level. I have an idea that could work. Let me add it to the list of new functionality.

[Marcoos]

I'm just glad to add a grain .........
Marco

[Chuck Hellebuyck]

I added a soft serial routine to my sample projects page.
I used the UART tool inside the PICkit 2 software as the terminal.
I just send the data through the programming pins RB6 and RB7 so I don't have to disconnect the PICkit 2 or attached a RS232 to USB convertor.
I just have the code posted, no schematic.
http://www.greatcowbasic.com/sample-projects.html