Logic Gates

Joltnjoe · 2004-12-14 07:23

I want to have pins 0 through 9 a logic inputs
using pins 11 through 14 as outputs to a BCD Decoder

If I want pins 0-9 at 000000011
to output 11-14 as 0010

·IF IN0=0,IN1=0,IN2=0,IN3=0,IN4=0,IN5=0,IN6=0,IN7=0,IN8=1.IN9=1
THEN LOW 11,LOW 12,HIGH,13,LOW 14

Is there a different way to do this
I want to go from
000000000·· BCD 0000
to
000000001·· BCD 0001
to
000000011·· BCD 0010
to
000000111·· BCD 0011
Etc
111111111·· BCD 1000

To do this as a constant LOOP

Joltnjoe · 2004-12-14 11:21

This is Joltnjoe

Will This program Work?

' EM 805 A/D Converter using Flash
' This Program is using the binary output of a A/D Converter
' using a Flash system

' {$STAMP BS2p}
' {$PBASIC 2.5}

DO

·IF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=0) AND
··· (IN6=0) AND (IN7=0) AND (IN8=0) AND (IN9=0)
··· THEN
··· LOW 11
··· LOW 12
··· LOW 13
··· LOW 14
·ELSEIF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=0)
··· AND (IN6=0) AND (IN7=0) AND (IN8=0) AND (IN9=1)
··· LOW 11
··· LOW 12
··· LOW 13
··· HIGH 14
LOOP

Help!!!

Jon Williams · 2004-12-14 14:21

What happens when you have an input like %11111100?

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Jon Williams
Applications Engineer, Parallax
Dallas Office

Lee Harker · 2004-12-14 16:38

It appears you are trying to create an output of a 4 bit binary number that represents the highest bit that is on. If that is the case, there is a nifty Pbasic function called "priority encoder" that would help out.
Lee

agentile · 2004-12-14 17:00

JoltnJoe,
If you know that you logic inputs will always be %00000001, %00000011,... %11111111, then you can write a routine to read the bits of your 10-bit word from LSB to MSB. A rough example of the decoder would work like this:

N=0 ' This is the decimal number
startread: ' begin subroutine
if input.lowbit=1 then shiftbits ' read the lowest bit, if = 0, then N = 0, if =1, then go to the next bit
debug dec N ' print to screen decimal value of N

shiftbits: ' routine to right shift bits
input=input>>1 ' move the second bit into the lsb
N=N+1 ' update N
if N>9 then done
goto startread

done:
end

hope this helps,
agentile

Jon Williams · 2004-12-14 17:50

Here's another approach:

Test_Bits:
  bCount = 0
  hBit = 0
  FOR idx = 0 TO 8
    IF bitsIn.LOWBIT(idx) = 1 THEN
      bCount = bCount + 1
      hBit = idx + 1
    ENDIF  
  NEXT
  RETURN

This returns the bit count and the highest bit set (duplication of NCD operator).

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Jon Williams
Applications Engineer, Parallax
Dallas Office

Joltnjoe · 2004-12-15 04:04

I tried this program it ran but did not do what·I planed

I had the Input statements on one line (the only way it worked)

but can I have it run like this

' EM 805 A/D Converter using Flash
' This Program is using the binary output of a A/D Converter
' using a Flash system

' {$STAMP BS2p}
' {$PBASIC 2.5}

DO
·IF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=0)
·AND (IN6=0) AND (IN7=0) AND (IN8=0) AND (IN9=0) THEN
··· LOW 11
··· LOW 12
··· LOW 13
··· LOW 14
··· PAUSE 500

·ELSEIF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=0)
·AND (IN6=0) AND (IN7=0) AND (IN8=0) AND (IN9=1) THEN
··· LOW 11
··· LOW 12
··· LOW 13
··· HIGH 14
··· PAUSE 500

·· ELSEIF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=0)
·· AND (IN6=0) AND (IN7=0) AND (IN8=1) AND (IN9=1) THEN
··· LOW 11
··· LOW 12
··· HIGH 13
··· LOW 14
··· PAUSE 500
·· ELSEIF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=0)
·· AND (IN6=0) AND (IN7=1) AND (IN8=1) AND (IN9=1) THEN
··· LOW 11
··· LOW 12
··· HIGH 13
··· HIGH 14
··· PAUSE 500
·· ELSEIF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=0)
·· AND (IN6=1) AND (IN7=1) AND (IN8=1) AND (IN9=1) THEN
··· LOW 11
··· HIGH 12
··· LOW 13
··· LOW 14
··· PAUSE 500
·· ELSEIF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=1)
·· AND (IN6=1) AND (IN7=1) AND (IN8=1) AND (IN9=1) THEN
··· LOW 11
··· HIGH 12
··· LOW 13
··· HIGH 14
··· PAUSE 500
·· ELSEIF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=1) AND (IN5=1)
·· AND (IN6=1) AND (IN7=1) AND (IN8=1) AND (IN9=1) THEN
··· LOW 11
··· HIGH 12
··· HIGH 13
··· LOW 14
··· PAUSE 500
·· ELSEIF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=1) AND (IN4=1) AND (IN5=1)
·· AND (IN6=1) AND (IN7=1) AND (IN8=1) AND (IN9=1) THEN
··· LOW 11
··· HIGH 12
··· HIGH 13
··· HIGH 14
··· PAUSE 500
·· ELSEIF (IN0=0) AND (IN1=0) AND (IN2=1) AND (IN3=1) AND (IN4=1) AND (IN5=1)
·· AND (IN6=1) AND (IN7=1) AND (IN8=1) AND (IN9=1) THEN
··· HIGH 11
··· LOW 12
··· LOW 13
··· LOW 14
··· PAUSE 500
·· ELSEIF (IN0=0) AND (IN1=1) AND (IN2=1) AND (IN3=1) AND (IN4=1) AND (IN5=1)
·· AND (IN6=1) AND (IN7=1) AND (IN8=1) AND (IN9=1) THEN
··· HIGH 11
··· LOW 12
··· LOW 13
··· HIGH 14
··· PAUSE 500
·· ENDIF

·· LOW 11
·· LOW 12
·· LOW 13
·· LOW 14
·· PAUSE 5

LOOP

Thank You

Logically Yours

Joltnjoe

Jon Williams · 2004-12-15 05:55

Man, that's a lot of work -- and possibly consuming a lot of code space dealing with all those bits (tricky internally).· Wtih PBASIC 2.5 came the SELECT..CASE structure.· You could recode something like this (partial):

bitsIn = INS & $1F
SELECT bitsIn
  CASE %000000000
    LOW 11
    LOW 12
    LOW 13
    LOW 14
  CASE %100000000
    LOW 11
    LOW 12
    LOW 13
    HIGH 14
 
...
 
ENDSELECT
PAUSE 500

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Jon Williams
Applications Engineer, Parallax
Dallas Office

Joltnjoe · 2004-12-16 04:57

How does this program identify the pin number?

How does it work in layman's terms?

I have a hard time programing but I need to learn

I tried PIC's but no support

I built a programable Tank ( Tamaya body ) using the Beo-Bot style design

Thank You

Joltnjoe

Jon Williams · 2004-12-16 15:40

Perhaps you should download a copy of "What's A Microcontroller?" and give it a read; it will get you up to speed on PBASIC programming pretty quickly.· Here's an explanation of the snippet is suggested:

bitsIn = INS & $1F         ' copy inputs to bitsIn; clear all but P0 - P8 values
SELECT bitsIn              ' compare bitsIn to a list of values
  CASE %000000000          ' if bitsIn = %000000000
    LOW 11                 ' make all controll pins low 
    LOW 12
    LOW 13
    LOW 14
  CASE %100000000          ' if bitsIn = %100000000
    LOW 11
    LOW 12
    LOW 13
    HIGH 14                ' make P14 high 
 
...
 
ENDSELECT
PAUSE 500                  ' wait 0.5 seconds

Note that this is only a partial listing; its purpose to show you that SELECT-CASE is a better programming option than the gigantic IF-THEN constructs used in an example above.

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Jon Williams
Applications Engineer, Parallax
Dallas Office

Post Edited (Jon Williams) : 12/16/2004 3:42:51 PM GMT

Chris Savage · 2004-12-16 16:04

Jon,
·· If I may step in just a moment...Yes, he should definately read the WAM tutorial.· Meanwhile, looking at it from his perspective, I think I know what he wants in the explanation...
JoltnJoe,
·· Jon's code works by reading ALL the pins you are reading at the same time, instead of testing each pin one at a time as you were.· Once you read the WAM tutorial you should have a better understanding of how this works, but it boils down to reading the ALL the pins at once:

bitsIn = INS & $1F         ' copy inputs to bitsIn; clear all but P0 - P8 values

This puts the state of ALL the pins into bitsIn.· Minus the pins you don't need.
It's the same as your code:

IF (IN0=0) AND (IN1=0) AND (IN2=0) AND (IN3=0) AND (IN4=0) AND (IN5=0) AND
    (IN6=0) AND (IN7=0) AND (IN8=0) AND (IN9=0)
    THEN

Except that you don't need that whole block of code for each change in the state of the pins.· Instead Jon's code is checking the state by using:

CASE %000000000          ' if bitsIn = %000000000

Which refers to the state of each input you were checking one at a time.· But in your code you're checking the state of each pin, for each pattern.· Jon is checking the state of the pins once, with less code, then comparing those values to the individual patterns you were looking for.

Definately read the "What's A Microcontroller"...It'll help alot down the road (And now!).· Good luck.

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Chris Savage

Knight Designs
324 West Main Street
P.O. Box 97
Montour Falls, NY 14865
(607) 535-6777

Business Page:·· http://www.knightdesigns.com
Personal Page:··· http://www.lightlink.com/dream/chris
Designs Page:··· http://www.lightlink.com/dream/designs
·

Jon Williams · 2004-12-16 16:38

Thanks for the assist, Chris. Joe... get WAM (you can download it free), you'll be glad you did.

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Jon Williams
Applications Engineer, Parallax
Dallas Office

Joltnjoe · 2004-12-17 02:55

I bought the kit and went through the book

I am a very logical thinking person but trying to get into programing

Like I said I like the product because of the support network

Jon Williams · 2004-12-17 03:04

Programming is logic applied to a specific problem. It will come, give yourself time and start small before working your way into very complex projects.

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Jon Williams
Applications Engineer, Parallax
Dallas Office

Logic Gates

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