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SEROUT question

ArchiverArchiver Posts: 46,084
edited 2003-12-01 14:43 in General Discussion
In the code below, there are 2 SEROUT statements.

1st SEROUT statement:
What exactly is sent by 1st SEROUT statement?
Is 20 sent as %00010100 and BL sent as %01111101?

2nd SEROUT statement:
Does it send out %00001100, then ASCII equivalent of "T", "h", "e"
etc.?

I'm trying to write to a serial LCD on pin 0. The LCD wants data at
9600 bps, inverted.

Thanks for help.



'{$STAMP BS2}
'{$PBASIC 2.5}

Baud CON 16468 'inverted, 9600 bps
TX CON 0
BackLite CON 20
BL CON 125
ClearLCD CON 12
SetCursor CON 17

PAUSE 500
SEROUT TX, Baud, [noparse][[/noparse]BackLite, BL]
SEROUT TX, Baud, [noparse][[/noparse]ClearLCD, "The Basic Stamp"]

END

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-08-07 20:12
    Why yes, I believe you have it exactly correct.

    '20' is sent as CHR(20), aka CHR($14),
    aka %00010100 (as a single BYTE).

    Then the single byte CHR(125), aka CHR($7D)
    is sent.

    Then CHR(12) (CHR($0C)), Then
    "T","h","e"...

    Problems:
    1. You are sending out pin 0. Pin 0 does
    NOT have a 232 driver on it. Does the LCD
    WANT a 232 driver? Typically, 'Invert' mode
    is used WITH a 232 driver. You either need
    to add a 232 driver to the Stamp side, or
    disable the jumper on the LCD side so it uses
    0..5Volt signaling. THEN, you have to test
    if the 'Invert' is still appropriate. Note
    you can't damage anything by using the wrong
    'Invert' mode -- so try it both ways and see
    what works.

    Note you CAN damage things by tying the
    output of a 232 driver directly to a Stamp
    pin -- you'll need a 22KOhm resistor in
    that case.

    It looks like you exactly understand what
    SEROUT is doing -- the gotcha is that
    'Invert' mode, and whether you REALLY
    need it or not. I suspect not.

    --- In basicstamps@yahoogroups.com, "newbiesda" <newbiesda@y...>
    wrote:
    > In the code below, there are 2 SEROUT statements.
    >
    > 1st SEROUT statement:
    > What exactly is sent by 1st SEROUT statement?
    > Is 20 sent as %00010100 and BL sent as %01111101?
    >
    > 2nd SEROUT statement:
    > Does it send out %00001100, then ASCII equivalent of "T", "h", "e"
    > etc.?
    >
    > I'm trying to write to a serial LCD on pin 0. The LCD wants data
    at
    > 9600 bps, inverted.
    >
    > Thanks for help.
    >
    >
    >
    > '{$STAMP BS2}
    > '{$PBASIC 2.5}
    >
    > Baud CON 16468 'inverted, 9600 bps
    > TX CON 0
    > BackLite CON 20
    > BL CON 125
    > ClearLCD CON 12
    > SetCursor CON 17
    >
    > PAUSE 500
    > SEROUT TX, Baud, [noparse][[/noparse]BackLite, BL]
    > SEROUT TX, Baud, [noparse][[/noparse]ClearLCD, "The Basic Stamp"]
    >
    > END
  • ArchiverArchiver Posts: 46,084
    edited 2003-08-07 20:20
    Actually, the code is working. I get what I expect on the serial LCD.
    The problem is that when I try to use another "counterfeit Stamp", it
    does not work.
    So, what I want to know is what exactly is the BS2 sending out with
    SEROUT 0, Baud, [noparse][[/noparse]20, 125]?

    What exactly does CHR(20) and CHR(125) equate to?
    Where can I find a chart that translates decimal number to equivalent
    ASCII code?

    Thanks.



    --- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
    wrote:
    > Why yes, I believe you have it exactly correct.
    >
    > '20' is sent as CHR(20), aka CHR($14),
    > aka %00010100 (as a single BYTE).
    >
    > Then the single byte CHR(125), aka CHR($7D)
    > is sent.
    >
    > Then CHR(12) (CHR($0C)), Then
    > "T","h","e"...
    >
    > Problems:
    > 1. You are sending out pin 0. Pin 0 does
    > NOT have a 232 driver on it. Does the LCD
    > WANT a 232 driver? Typically, 'Invert' mode
    > is used WITH a 232 driver. You either need
    > to add a 232 driver to the Stamp side, or
    > disable the jumper on the LCD side so it uses
    > 0..5Volt signaling. THEN, you have to test
    > if the 'Invert' is still appropriate. Note
    > you can't damage anything by using the wrong
    > 'Invert' mode -- so try it both ways and see
    > what works.
    >
    > Note you CAN damage things by tying the
    > output of a 232 driver directly to a Stamp
    > pin -- you'll need a 22KOhm resistor in
    > that case.
    >
    > It looks like you exactly understand what
    > SEROUT is doing -- the gotcha is that
    > 'Invert' mode, and whether you REALLY
    > need it or not. I suspect not.
    >
    > --- In basicstamps@yahoogroups.com, "newbiesda" <newbiesda@y...>
    > wrote:
    > > In the code below, there are 2 SEROUT statements.
    > >
    > > 1st SEROUT statement:
    > > What exactly is sent by 1st SEROUT statement?
    > > Is 20 sent as %00010100 and BL sent as %01111101?
    > >
    > > 2nd SEROUT statement:
    > > Does it send out %00001100, then ASCII equivalent
    of "T", "h", "e"
    > > etc.?
    > >
    > > I'm trying to write to a serial LCD on pin 0. The LCD wants data
    > at
    > > 9600 bps, inverted.
    > >
    > > Thanks for help.
    > >
    > >
    > >
    > > '{$STAMP BS2}
    > > '{$PBASIC 2.5}
    > >
    > > Baud CON 16468 'inverted, 9600 bps
    > > TX CON 0
    > > BackLite CON 20
    > > BL CON 125
    > > ClearLCD CON 12
    > > SetCursor CON 17
    > >
    > > PAUSE 500
    > > SEROUT TX, Baud, [noparse][[/noparse]BackLite, BL]
    > > SEROUT TX, Baud, [noparse][[/noparse]ClearLCD, "The Basic Stamp"]
    > >
    > > END
  • ArchiverArchiver Posts: 46,084
    edited 2003-08-07 20:26
    CHR(20) is old PC Basic syntax, for the
    ascii character whose code is '20' (ie the
    'space' character). I like that syntax
    because it is relatively un-ambiguous.

    If I say 'output 20', have I said to
    output the two characters '2' and '0', or
    the single byte '20'. And if it IS the
    single byte '20', is that hexadecimal
    '20' or decimal '20'.

    Saying 'output CHR(20)' says the single
    byte represented by the decimal value 20.

    You'll need an ASCII character table to
    get more translations -- though I suspect
    the codes you're sending out are defined
    by the LCD vendor to do 'special things'
    with its LCD -- move cursor, blank screen,
    etc.

    --- In basicstamps@yahoogroups.com, "newbiesda" <newbiesda@y...>
    wrote:
    > Actually, the code is working. I get what I expect on the serial
    LCD.
    > The problem is that when I try to use another "counterfeit Stamp",
    it
    > does not work.
    > So, what I want to know is what exactly is the BS2 sending out with
    > SEROUT 0, Baud, [noparse][[/noparse]20, 125]?
    >
    > What exactly does CHR(20) and CHR(125) equate to?
    > Where can I find a chart that translates decimal number to
    equivalent
    > ASCII code?
    >
    > Thanks.
    >
    >
    >
    > --- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
    > wrote:
    > > Why yes, I believe you have it exactly correct.
    > >
    > > '20' is sent as CHR(20), aka CHR($14),
    > > aka %00010100 (as a single BYTE).
    > >
    > > Then the single byte CHR(125), aka CHR($7D)
    > > is sent.
    > >
    > > Then CHR(12) (CHR($0C)), Then
    > > "T","h","e"...
    > >
    > > Problems:
    > > 1. You are sending out pin 0. Pin 0 does
    > > NOT have a 232 driver on it. Does the LCD
    > > WANT a 232 driver? Typically, 'Invert' mode
    > > is used WITH a 232 driver. You either need
    > > to add a 232 driver to the Stamp side, or
    > > disable the jumper on the LCD side so it uses
    > > 0..5Volt signaling. THEN, you have to test
    > > if the 'Invert' is still appropriate. Note
    > > you can't damage anything by using the wrong
    > > 'Invert' mode -- so try it both ways and see
    > > what works.
    > >
    > > Note you CAN damage things by tying the
    > > output of a 232 driver directly to a Stamp
    > > pin -- you'll need a 22KOhm resistor in
    > > that case.
    > >
    > > It looks like you exactly understand what
    > > SEROUT is doing -- the gotcha is that
    > > 'Invert' mode, and whether you REALLY
    > > need it or not. I suspect not.
    > >
    > > --- In basicstamps@yahoogroups.com, "newbiesda" <newbiesda@y...>
    > > wrote:
    > > > In the code below, there are 2 SEROUT statements.
    > > >
    > > > 1st SEROUT statement:
    > > > What exactly is sent by 1st SEROUT statement?
    > > > Is 20 sent as %00010100 and BL sent as %01111101?
    > > >
    > > > 2nd SEROUT statement:
    > > > Does it send out %00001100, then ASCII equivalent
    > of "T", "h", "e"
    > > > etc.?
    > > >
    > > > I'm trying to write to a serial LCD on pin 0. The LCD wants
    data
    > > at
    > > > 9600 bps, inverted.
    > > >
    > > > Thanks for help.
    > > >
    > > >
    > > >
    > > > '{$STAMP BS2}
    > > > '{$PBASIC 2.5}
    > > >
    > > > Baud CON 16468 'inverted, 9600 bps
    > > > TX CON 0
    > > > BackLite CON 20
    > > > BL CON 125
    > > > ClearLCD CON 12
    > > > SetCursor CON 17
    > > >
    > > > PAUSE 500
    > > > SEROUT TX, Baud, [noparse][[/noparse]BackLite, BL]
    > > > SEROUT TX, Baud, [noparse][[/noparse]ClearLCD, "The Basic Stamp"]
    > > >
    > > > END
  • ArchiverArchiver Posts: 46,084
    edited 2003-08-08 12:26
    What does BAUD 16468 (inverted) mean in Basic Stamp 2?

    Suppose I have:

    Baud CON 16468 'inverted 9600 bps
    data1 VAR Byte
    data1 = %11100001
    SEROUT 0, Baud, [noparse][[/noparse]data1]

    What does the above SEROUT send exactly?

    Since Baud of 16468 is 9600 bps inverted (according to BS2 manual),
    I assume that BS2 sends out starting with LSB first, 0,1,1,1,1,0,0,0
    (which is same as data1 inverted, LSB first).

    Is my assumption correct?

    Thank you.

    --- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
    wrote:
    > CHR(20) is old PC Basic syntax, for the
    > ascii character whose code is '20' (ie the
    > 'space' character). I like that syntax
    > because it is relatively un-ambiguous.
    >
    > If I say 'output 20', have I said to
    > output the two characters '2' and '0', or
    > the single byte '20'. And if it IS the
    > single byte '20', is that hexadecimal
    > '20' or decimal '20'.
    >
    > Saying 'output CHR(20)' says the single
    > byte represented by the decimal value 20.
    >
    > You'll need an ASCII character table to
    > get more translations -- though I suspect
    > the codes you're sending out are defined
    > by the LCD vendor to do 'special things'
    > with its LCD -- move cursor, blank screen,
    > etc.
    >
    > --- In basicstamps@yahoogroups.com, "newbiesda" <newbiesda@y...>
    > wrote:
    > > Actually, the code is working. I get what I expect on the serial
    > LCD.
    > > The problem is that when I try to use another "counterfeit
    Stamp",
    > it
    > > does not work.
    > > So, what I want to know is what exactly is the BS2 sending out
    with
    > > SEROUT 0, Baud, [noparse][[/noparse]20, 125]?
    > >
    > > What exactly does CHR(20) and CHR(125) equate to?
    > > Where can I find a chart that translates decimal number to
    > equivalent
    > > ASCII code?
    > >
    > > Thanks.
    > >
    > >
    > >
    > > --- In basicstamps@yahoogroups.com, "Allan Lane"
    <allan.lane@h...>
    > > wrote:
    > > > Why yes, I believe you have it exactly correct.
    > > >
    > > > '20' is sent as CHR(20), aka CHR($14),
    > > > aka %00010100 (as a single BYTE).
    > > >
    > > > Then the single byte CHR(125), aka CHR($7D)
    > > > is sent.
    > > >
    > > > Then CHR(12) (CHR($0C)), Then
    > > > "T","h","e"...
    > > >
    > > > Problems:
    > > > 1. You are sending out pin 0. Pin 0 does
    > > > NOT have a 232 driver on it. Does the LCD
    > > > WANT a 232 driver? Typically, 'Invert' mode
    > > > is used WITH a 232 driver. You either need
    > > > to add a 232 driver to the Stamp side, or
    > > > disable the jumper on the LCD side so it uses
    > > > 0..5Volt signaling. THEN, you have to test
    > > > if the 'Invert' is still appropriate. Note
    > > > you can't damage anything by using the wrong
    > > > 'Invert' mode -- so try it both ways and see
    > > > what works.
    > > >
    > > > Note you CAN damage things by tying the
    > > > output of a 232 driver directly to a Stamp
    > > > pin -- you'll need a 22KOhm resistor in
    > > > that case.
    > > >
    > > > It looks like you exactly understand what
    > > > SEROUT is doing -- the gotcha is that
    > > > 'Invert' mode, and whether you REALLY
    > > > need it or not. I suspect not.
    > > >
    > > > --- In basicstamps@yahoogroups.com, "newbiesda"
    <newbiesda@y...>
    > > > wrote:
    > > > > In the code below, there are 2 SEROUT statements.
    > > > >
    > > > > 1st SEROUT statement:
    > > > > What exactly is sent by 1st SEROUT statement?
    > > > > Is 20 sent as %00010100 and BL sent as %01111101?
    > > > >
    > > > > 2nd SEROUT statement:
    > > > > Does it send out %00001100, then ASCII equivalent
    > > of "T", "h", "e"
    > > > > etc.?
    > > > >
    > > > > I'm trying to write to a serial LCD on pin 0. The LCD wants
    > data
    > > > at
    > > > > 9600 bps, inverted.
    > > > >
    > > > > Thanks for help.
    > > > >
    > > > >
    > > > >
    > > > > '{$STAMP BS2}
    > > > > '{$PBASIC 2.5}
    > > > >
    > > > > Baud CON 16468 'inverted, 9600 bps
    > > > > TX CON 0
    > > > > BackLite CON 20
    > > > > BL CON 125
    > > > > ClearLCD CON 12
    > > > > SetCursor CON 17
    > > > >
    > > > > PAUSE 500
    > > > > SEROUT TX, Baud, [noparse][[/noparse]BackLite, BL]
    > > > > SEROUT TX, Baud, [noparse][[/noparse]ClearLCD, "The Basic Stamp"]
    > > > >
    > > > > END
  • ArchiverArchiver Posts: 46,084
    edited 2003-12-01 01:14
    i am using a motor controller from pololu. the problem is that it
    came with sample code for a bs2 and i need it for a bsx2. the serout
    is says "serout 14, 32" i am not sure the translation to bsx2. if
    anyone has an idea please let me know.
    thanks!
    k
  • ArchiverArchiver Posts: 46,084
    edited 2003-12-01 06:14
    At 01:14 AM 12/1/03 +0000, kirsten wrote:
    >i am using a motor controller from pololu. the problem is that it
    >came with sample code for a bs2 and i need it for a bsx2. the serout
    >is says "serout 14, 32" i am not sure the translation to bsx2. if
    >anyone has an idea please let me know.
    >thanks!
    >k
    Kirsten -

    The general formula for BAUDMODE on the BS-2 is:

    INT(1,000,000/baud rate)-20 thus (1,000,000/19,200)-20 = 32

    The sample program provided uses a BAUDMODE of 32 which equals 19,200 BPS.

    The general formula for BAUDMODE for the BS-2SX is:

    INT(2,500,000/baud rate)-20 thus (2,500,000/19,200)-20 = 110

    Substitution of 110 where you find 32 in the SEROUT statements, will alter
    the program appropriately.

    There are other factors to consider under some circumstances, as indicated in
    the Stamp PBASIC Manual, but none apply in this example. These factors include
    parity, and TRUE or INVERTED formats.

    Personally, I would use a format like this:

    BAUDMODE CON 110

    SEROUT 14, BAUDMODE, [noparse][[/noparse]$80,0,0,speed]

    This would make any future changes to BAUDMODE real easy, by merely
    changing the value of BAUDMODE once at the beginning of the program. No
    variable space is
    used by CON values. As far as I am aware, "BAUDMODE" is not a reserved word.

    Regards,

    Bruce Bates
  • ArchiverArchiver Posts: 46,084
    edited 2003-12-01 14:43
    I believe the Pololu docs tell you the communication is at 19.2K baud.
    In the help file you'll find an equation for calcuating the baud
    parameter for any baud rate:

    BS2sx, BS2p : INT(2,500,00 / baud) - 20

    In your case, then, the baud parameter becomes 110. With new features
    of the BASIC Stamp IDE you can use conditional compilation to make
    switching Stamps easier. Here's a bit of code that I've been using
    lately:

    #SELECT $STAMP
    #CASE BS2, BS2E, BS2PE
    T1200 CON 813
    T2400 CON 396
    T9600 CON 84
    T192K CON 32
    #CASE BS2SX, BS2P
    T1200 CON 2063
    T2400 CON 1021
    T9600 CON 240
    T192K CON 110
    #ENDSELECT

    -- Jon Williams
    -- Applications Engineer, Parallax
    -- Dallas Office


    Original Message
    From: kirsten [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=IhRZDEkysm6gU1G1B9e98w1-7Eg-pUsw7DY7WUFO7jfaKeZNz0OjixmkSfiCJ1DaRNFcKuLg8OqkaTiM3fc]kirsten@p...[/url
    Sent: Sunday, November 30, 2003 7:14 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] serout question


    i am using a motor controller from pololu. the problem is that it
    came with sample code for a bs2 and i need it for a bsx2. the serout
    is says "serout 14, 32" i am not sure the translation to bsx2. if
    anyone has an idea please let me know.
    thanks!
    k



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