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Stamp-O-Scope display Chapter 5 Parallax book: Basic Analog and Digital 1.3 version — Parallax Forums

Stamp-O-Scope display Chapter 5 Parallax book: Basic Analog and Digital 1.3 version

Keith HiltonKeith Hilton Posts: 150
in BASIC Stamp
I can not get my Stamp-O-Scope to work. I am referring to Chapter 5 Parallax book: Basic Analog and Digital 1.3 version. As the text said, I changed the code of the Program Listing 4.1 to the code changes listed on pages 91 and 91 of the book. The code ran, but I did not have a triangle wave form. I had a row of dots up the Debug display on the left side. I know my circuit is correct, because it ran with the circuit on page 83--Figure 4-8, D/A Circuit with a buffer. What is extremely confusing is this: On page 92 it says to modify the Display subroutine to look like this:
Display:
v3 = adcBits / 8
DEBUG REP " "\v3, "*", CR
RETURN
Then in the book when they start explaining the code on page 96 they have something totally different for the Display. Here is what is on page 96.
Display:
DEBUG REP " "\adcBits/4, "*", CR
RETURN
I tried running the code Display both ways, and neither way displayed the triangle wave form. I want to find out what I am doing wrong, and get a triangle wave form on my Debug display. Here is my code below. My circuit is exactly the same as the circuit diagram on page 83.
' {$STAMP BS2}
' {$PBASIC 2.5}
'Basic Analog and Digital--PL5_1R0,bs2
'Digital Voltmeter (DVM) . D/A Converter Added
'
[Declarations]
adcBits VAR Byte
v VAR Byte
r VAR Byte
v2 VAR Byte
v3 VAR Byte
n VAR Nib
'
[ Initialization ]
CS PIN 0
CLK PIN 1
DataOutput PIN 2

DEBUG CLS
'Start display.
DO
FOR n = 7 TO 15
GOSUB Main
NEXT
FOR n = 14 TO 8
GOSUB Main
NEXT
LOOP

'
[ Main Routine ]
Main:
GOSUB DAC
GOSUB ADC_Data
'GOSUB Calc_Volts
GOSUB Display
RETURN
'
[ Subroutines ]
DAC:
DIRB = 15
OUTB = n
PAUSE 50
RETURN

ADC_Data:
HIGH CS
LOW CS
LOW CLK
PULSOUT CLK, 210
SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\8]
RETURN
Calc_Volts:
v = 5 * adcBits/ 255
r = 5 * adcBits // 255
v2 = 100 * R / 255
v3 = 100 * R // 255
v3 = 10 * v3 /255
IF (v3 >= 5) THEN v2 = v2 +1
IF (v2 >= 100) THEN
v = v + 1
v2 = 0
ENDIF
RETURN

Display:
v3 = adcBits / 8
DEBUG REP " "\v3, "*", CR
RETURN

Comments

  • GenetixGenetix Posts: 1,754
    Keith,

    Double-check your ADC_Data and Display routines because they look different than what I see the 1.4 text.
    LOW CS turns on the ADC because Chip Select in an Active-Low input, and HIGH CS turns it off.
    Also, in the DEBUG command adcBits should be divided by 4 and not 8 since we're using a 4-Bit DAC. 
    ADC_Data:
  LOW CLK
  LOW CS
  PULSOUT CLK, 210
  SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\8]
  HIGH CS
RETURN

Display:
  DEBUG REP " "\adcBits/4,"*", CR
RETURN
  • Keith HiltonKeith Hilton Posts: 150
    Thanks for trying to help Genetix. In the 1.4 program listing chapter 4, page 71, it lists:
    ADC_Data:
    HIGH CS
    LOW CS
    LOW CLK
    Nothing in chapter 5, pages 91 and 92 was said about changing the: HIGH CS
    What you did was add it right before the RETURN. Which seemed the right thing to do.
    Also: I can't understand why on page 92 they list the code change for Display, then on 96 when explaining the Display code, the have something totally different.
    OK, I ran the code with your changes Genetix, and the triangle wave form did not appear. I got the same results as before, just a straight line up and down, on the left side of the Debug screen. I need to get this triangle wave form working.
  • Miguel RodriguezMiguel Rodriguez Posts: 24
    Kieth



    On page 92 the book says to change the Display: routine to this.

    Display:
    DEBUG REP " "\adcBits/4,"*", CR
    RETURN



    However in your forum post you said that on page 92 the book asks for you to modify the Display routine code to look like this.

    v3 = adcBits / 8
    DEBUG REP " "\v3, "*", CR
    RETURN




    What you see on page 92 and what I see on page 92 is different.






    Then on page 96 they start explaining the code. The code I see on page 96 is the same as on page 92.

    Display:
    DEBUG REP " "\adcBits/4,"*", CR
    RETURN


    I don't see where you are getting the code you reference.

    v3 = adcBits / 8
    DEBUG REP " "\v3, "*", CR
    RETURN


    That may be where you are going wrong. I wonder if you have a different version of the book? Are you getting your copy from our site?

    Best Regards,
    Miguel Rodriguez
    Parallax Inc. Tech Support

  • Keith HiltonKeith Hilton Posts: 150
    Miguel, the problem here is I have an old Parallax book Version 1.3 which has an 'obvious' mistake. If you will look up at the start of my post, I said I tried to run the code 'each' way without success either way.
    Display:
    DEBUG REP " "\adcBits/4,"*", CR
    RETURN
    or
    Display:
    v3 = adcBits / 8
    DEBUG REP " "\v3, "*", CR
    RETURN
    Try running the code either way. Look at your Debug screen and you get a row of dots up the left hand side, when you should get a triangle wave form.

  • Keith HiltonKeith Hilton Posts: 150
    I tried running the code again with what you suggested Miguel. Same results--dotted line up and down on the left side of the Debug screen. I think the code in this 1.3 version of the Parallax book has some other mistake. Here is the code I ran.
    ' {$STAMP BS2}
    ' {$PBASIC 2.5}
    'Basic Analog and Digital--PL5_1R0,bs2
    'Digital Voltmeter (DVM) . D/A Converter Added
    '
    [Declarations]
    adcBits VAR Byte
    v VAR Byte
    r VAR Byte
    v2 VAR Byte
    v3 VAR Byte
    n VAR Nib
    '
    [ Initialization ]
    CS PIN 0
    CLK PIN 1
    DataOutput PIN 2

    DEBUG CLS
    'Start display.
    DO
    FOR n = 7 TO 15
    GOSUB Main
    NEXT
    FOR n = 14 TO 8
    GOSUB Main
    NEXT
    LOOP

    '
    [ Main Routine ]
    Main:
    GOSUB DAC
    GOSUB ADC_Data
    'GOSUB Calc_Volts
    GOSUB Display
    RETURN
    '
    [ Subroutines ]
    DAC:
    DIRB = 15
    OUTB = n
    PAUSE 50
    RETURN

    ADC_Data:
    HIGH CS
    LOW CS
    LOW CLK
    PULSOUT CLK, 210
    SHIFTIN DataOutput,CLK,MSBPOST,[adcBits\8]

    RETURN
    Calc_Volts:
    v = 5 * adcBits/ 255
    r = 5 * adcBits // 255
    v2 = 100 * R / 255
    v3 = 100 * R // 255
    v3 = 10 * v3 /255
    IF (v3 >= 5) THEN v2 = v2 +1
    IF (v2 >= 100) THEN
    v = v + 1
    v2 = 0
    ENDIF
    RETURN

    Display:
    DEBUG REP " "\adcBits/4,"*", CR
    RETURN
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    Always use the latest version of any books or code from our website when possible. It is possible at some point that we made changes to things and that is causing a consistency issue between your examples and ours.

    A PDF of the V1.4 book can be downloaded free here: https://www.parallax.com/downloads/basic-analog-and-digital-text
  • Keith HiltonKeith Hilton Posts: 150
    I figured it out. Here is the part of my code that screwed things up.
    'GOSUB Calc_Volts
    It should have been this.
    GOSUB CALC_Volts
    A very tiny mistake that I and everyone else overlooked. I suppose this means I am learning something.
    I am so green at coding I began to wonder if I would ever catch on. I still feel like I only know 1% of what I need to know to be able to code. Winners never quit and quitters never win. Boys---Chalk this one up to determination, I got it working.
  • Keith HiltonKeith Hilton Posts: 150
    That mistake was in the main routine.
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