SX Video - Output Logic question

T&E Engineer

I'm sure someone has done this before and it can also be related to the BS2 output logic too. However, in this case I am refering to the SX Video module.

The outputs are arranged from Out.0 to Out.7 with setting them high by assigning a binary value to each output. (e.g. Out.0=1, Out.1=2, Out.2=4, Out.3=8 ... Out.7=128)
Add the values of the pins you want on (+5vdc) and send the value to the video module.

Examples:

T4800······ CON···· 188
Inverted····CON···· $4000
Baud········ CON···· T4800 + Inverted
Sout········ PIN 3····' Serial from SX Video module to P3
v_Outs······CON 134

SEROUT Sout, Baud, [noparse][[/noparse]v_Outs, 2]
'This command turns Out.1 HIGH
'It also turns Out.0,··· 2, 3, 4, 5, 6, 7 LOW

SEROUT Sout, Baud, [noparse][[/noparse]v_Outs, 8]
'This command turns Out.3 HIGH
'It also turns Out.1, 2,··· 4, 5, 6, 7 Low

SEROUT Sout, Baud, [noparse][[/noparse]v_Outs, 254]
'This command turns Out.1, 2, 3, 4, 5, 6, 7 HIGH
'It also turns Out.0 LOW

The question is how to turn on Out.3 (HIGH) without·changing the·condition of·Out.1 (either HIGH or LOW).

I should be able to turn on Out.3 (HIGH) and leave the other outputs in their previous states (either HIGH or LOW).

Bean??? or anyone else with similar logic experience.


·

Jon Williams

You need to keep track of the current status.· You could, for example, keep status byte like this:

vidOuts··· VAR·· Byte
vOut1····· VAR·· vidOuts.0
vOut2····· VAR·· vidOuts.1
vOut3····· VAR·· vidOuts.2

Main:
· vOut1 = 1
··GOSUB Update_Vid_Outs
· PAUSE 1000
· vOut2 = 1
· GOSUB Update_Vid_Outs

·· ...

Update_Vid_Outs:
· SEROUT VMod, Baud, [noparse][[/noparse]134, vidOuts]
· RETURN

You can, of course, alias as many of the bits of "vidOuts" as you need for your program.

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Jon Williams
Applications Engineer, Parallax

T&E Engineer

Jon,

Thanks so much! You are certainly quick!

I will try this out and let you know. I actually thought it would deal with some sort of an AND & or OR type statement. But I will try this out.

Here is the basic test program I am working with:



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


'

---

' I/O Definitions
'

---

#SELECT $STAMP
· #CASE BS2, BS2E, BS2PE
··· T1200··· CON···· 813
··· T2400··· CON···· 396
··· T4800··· CON···· 188
··· T9600··· CON···· 84
··· T19K2··· CON···· 32
··· T38K4··· CON···· 6
· #CASE BS2SX, BS2P
··· T1200··· CON···· 2063
··· T2400··· CON···· 1021
··· T4800··· CON···· 500
··· T9600··· CON···· 240
··· T19K2··· CON···· 110
··· T38K4··· CON···· 45
#ENDSELECT
SevenBit···· CON···· $2000
Inverted···· CON···· $4000
Open········ CON···· $8000

' Video commands
v_CrsrXY···· CON 2
v_Null······ CON 128
v_InvOn····· CON 129
v_InvOff···· CON 130
v_InvScrn··· CON 131
v_PlotXY···· CON 132
v_UnplotXY·· CON 133
v_Outs······ CON 134
v_Version··· CON 135
v_DecByte··· CON 136
v_HexByte··· CON 137

' Audio command
a_Sound····· CON 138···················· ' Pitch, Duration
a_Bell······ CON 7······················ ' 1.5 KHz tone for 170 mSec (same as BELL)

Baud········ CON···· T4800 + Inverted
Sout········ PIN 3······················ ' Serial from SX Video module to P3

BinOutHIGH·· VAR Byte
BinOutLOW··· VAR Byte

BinOutHIGH = 1·························· 'Set Out.0 High, Out.1-7 Low
BinOutLOW = 255 - BinOutHIGH············ 'Set Out.1-7 High, Out.0 Low

SEROUT Sout, Baud, [noparse][[/noparse]v_Outs, BinOutHIGH]

...

PS: I have gotten my Video Clock to talk while displaying time. I need to free up some BS2 I/O and wanted to use the SX Video Outputs where ever I could.

PS: On a side note...what are the rules as far as using sniplets of your code or from Chris from past published projects (i.e. Nuts and Volts #66 ISD Lab , and Binary Digital Clock, etc..). I don't want to Plagerize but I know I have used code before from other programmers with no problem too giving them credit too for their work.

Jon Williams

You are free to use code published by Parallax as you see fit (personal or commercial projects), so long as you accept that the code is published as-is with no warranty, expressed or implied. The only thing you may not do is claim copyright on that code in order to prevent others from using it.

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Jon Williams
Applications Engineer, Parallax

T&E Engineer

Jon,

The code sniplet you wrote caused an "Expected a variable modifier" error. I saw what it was and fixed it.

You wrote:

vidOuts··· VAR·· Byte
vOut1····· VAR·· vidOuts.0
vOut2····· VAR·· vidOuts.1
vOut3····· VAR·· vidOuts.2

It should be:

vidOuts··· VAR·· Byte
vOut1····· VAR·· vidOuts.BIT0
vOut2····· VAR·· vidOuts.BIT1
vOut3····· VAR·· vidOuts.BIT2

It works very well. I will post my code in the Projects section.

BEAN - Maybe you can use this as reference on your website for the SX Video Module.

Jon Williams

Sorry, have been working with SX/B a lot lately, and used that style.

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Jon Williams
Applications Engineer, Parallax