115200 baud on COM2

[MGG]

Hi.
Does anyone know how to open COM2 with baud rates in excess of 9600, in particular 115200?


Thanks.....

[Plasma]

From the ABC Packets:

Code:

'===========================================================================
' Subject: BEYOND 19200                      Date: Unknown Date (00:00)  
'  Author: Donn Bly                          Code: QB, QBasic, PDS        
'    Keys: BEYOND,19200                    Packet: MODEM.ABC
'===========================================================================
DECLARE SUB BaudLatch ()
'Use the straight OPEN COM statement for 19200.  To go higher you can
'use this code (originally from Donn Bly):

BaudLatch

SUB BaudLatch   'enables 38400 baud  want to put in com3 and com4 support
'NewBaud$ = "38400"
'BaudNum% = 3   'for 38.4
'BaudNum% = 2  'for 56000
BaudNum% = 1 'for 115K
Port$ = "COM4:"

SELECT CASE Port$
        CASE "COM1:"
                BaseAddress% = &H3F8
        CASE "COM2:"
                BaseAddress% = &H2F8
        CASE "COM3:"
                BaseAddress% = &H3E8
        CASE "COM4:"
                BaseAddress% = &H2E8
END SELECT
        OldLSR% = INP(BaseAddress% + 3)
        OUT (BaseAddress% + 3), (OldLSR% OR &H80)   ' Enable the Divisor Latch
        OUT (BaseAddress% + 0), (BaudNum% MOD &HFF) ' Lo Byte of Baud Rate
        OUT (BaseAddress% + 1), (BaudNum% \ &H100)  ' Hi Byte of baud Rate
        OUT (BaseAddress% + 3), OldLSR%             ' Disable Divisor Latch
END SUB

[MGG]

Thanks Plasma. I will try this code shortly.

MGG....

[MGG]

Hi again. My understanding of INP and OUT are that they read and write bytes from/to a hardware port. I failed to mention
that I must send a string of characters to COM2 (request
packet) and receive back characters (response packet), i.e.
something like this:

Rqst_Pkt = "440900000000d35e"
open "com2:115200,n,8,1" for random as #1
print #1, Rqst_Pkt
sleep 1
line input #1, Resp_Pkt
...

Is this do-able in QB7?

Thanks,

MGG...

[Plasma]

Should be...

Code:

DEFINT A-Z
DECLARE SUB ComSpeed (Port, Baud&)

ComSpeed 2, 115200
OPEN "COM2: ,N,8,1" FOR RANDOM AS #1
Rqst.Pkt$ = "440900000000d35e"
PRINT #1, Rqst.Pkt$
SLEEP 1
LINE INPUT #1, Resp.Pkt$
CLOSE #1

SUB ComSpeed (Port, Baud&)

  ' Based on BaudLatch() sub by Donn Bly
  '
  '  Port = COM Port (1, 2, 3, or 4)
  ' Baud& = Baud setting (9600, 14400, 19200, 38400, 57600, 115200, etc.)

  BaudDiv = 115200 / Baud&
  IF BaudDiv = 0 THEN BaudDiv = 1
  SELECT CASE Port
    CASE 4
      BaseAddr = &H2E8  ' com4
    CASE 3
      BaseAddr = &H3E8  ' com3
    CASE 2
      BaseAddr = &H2F8  ' com2
    CASE ELSE
      BaseAddr = &H3F8  ' com1
  END SELECT

  OldLSR = INP(BaseAddr + 3)
  OUT BaseAddr + 3, OldLSR OR &H80    ' Enable the Divisor Latch
  OUT BaseAddr + 0, BaudNum MOD &HFF  ' Lo Byte of Baud Rate
  OUT BaseAddr + 1, BaudNum \ &H100   ' Hi Byte of baud Rate
  OUT BaseAddr + 3, OldLSR            ' Disable Divisor Latch

END SUB

[MGG]

You're fast and you're good. I will try this and let you know.

Thanks,

MG........

[R@dioman]

Plasma knows everything. :lol: I bet you can't stump him. That should be a challenge in the challenge section.