LCD tachometer help

tgraz34 · 2010-03-01 00:43

Im currently using this code to display RPM and a bargraph on a LCD screen.

The problem is that i have 4 zeros infront of RPM and i dont want them to be there.

I know that its because of the DEC4 command in the subroutine Def_Horiz_Bar_Char:.

Does anyone know of a way to get around this problem.

' -----[noparse][[/noparse] Title ]--------------------------------------------------------------
' Smart Sensors and Applications - HorizBarGraph.bs2
' Display values entered into the Debug Terminal's Receive windowpane
' as horizontal bar graph data in the LCD.

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

' -----[noparse][[/noparse] I/O Pins ]-----------------------------------------------------------

LcdPin         PIN     15
SpeedIn        PIN     0
' -----[noparse][[/noparse] Constants ]----------------------------------------------------------

T9600          CON     84                    ' True, 8-bits, no parity, 9600
Capture        CON     5000
LcdCls         CON     12                    ' Form feed -> clear screen
LcdCr          CON     13                    ' Carriage return
LcdOff         CON     21                    ' Turns display off
LcdOn          CON     22                    ' Turns display on
Line0          CON     128                   ' Line 0, character 0
Line1          CON     148                   ' Line 1, character 0
Define         CON     248                   ' Address defines cust char 0

' -----[noparse][[/noparse] Variables ]----------------------------------------------------------
rpm            VAR     Word
pulses         VAR     Word
percent        VAR     Byte
custChar       VAR     Nib                   ' Custom charcter selector
index          VAR     Nib                   ' Eeprom index variable
dotLine        VAR     Byte                  ' 5-pixel dotted line
cursor         VAR     Nib                   ' Cursor placement
value          VAR     Byte                  ' Value to be graphed.
charCnt        VAR     Byte                  ' Character counting variable
line           VAR     Byte                  ' Line0 or Line1

' -----[noparse][[/noparse] Initialization ]-----------------------------------------------------

PAUSE 100                                    ' Debounce power supply
SEROUT LcdPin, T9600, [noparse][[/noparse]LcdOn, LcdCls]        ' Initialize LCD
SEROUT LcdPin, T9600, [noparse][[/noparse]137, "RPM" ]
PAUSE 5                                      ' 5 ms delay for clearing display

custChar = 3                                 ' Select Custom Character 3
dotLine = %11111                             ' Black all pixels in each line
GOSUB Def_Horiz_Bar_Char                     ' Character define subroutine

line = Line1

DO
  GOSUB Acquire_RPM
  value = (RPM / 35)
  GOSUB Bar_Graph:
LOOP

' Acquire_RPM
Acquire_RPM:
  COUNT SpeedIn, Capture, Pulses
  rpm = (pulses * 12)
  RETURN

' Bar_Graph
Bar_Graph:

  ' Fill from left with black bars
  value = value MAX 100
  charCnt = value / 5                        ' Number of black bars
  custChar = 3                               ' Choose black custom character

  IF charCnt > 0 THEN                        ' If black bars to print then
    FOR cursor = 0 TO charCnt - 1            ' Print charCnt - 1 black bars
      GOSUB Disp_Cust_Char                   ' Print the black bar
    NEXT
  ENDIF

  ' Display Custom Character 2 with a certain number of black columns.

  cursor = charCnt                           ' Place cursor
  custChar = value // 5                      ' How many 5ths of a bar?
  ' Choose bit pattern for custom character definition
  LOOKUP custChar,
         [noparse][[/noparse]%00000, %10000, %11000, %11100, %11110],
         dotLine
  custChar = 2                               ' Set custom character to 2
  GOSUB Def_Horiz_Bar_Char                   ' Define the custom character
  GOSUB Disp_Cust_Char                       ' Display the custom character

  ' Print over everything to the right with spaces.

  IF (charCnt + 1) < 15 THEN                 ' Partial char left of char 15?
    FOR cursor = (charCnt + 1) TO 15         ' Fill to right with " "
      SEROUT LcdPin, T9600,
             [noparse][[/noparse]line + cursor, " "]
    NEXT
  ELSEIF value = 80 THEN                     ' Special case: value = 80
    SEROUT LcdPin, T9600,
           [noparse][[/noparse]line + cursor, 3]
  ELSEIF charCnt = 14 THEN                   ' Special case: 75 <= value <= 80
    SEROUT LcdPin, T9600, [noparse][[/noparse]line + 15, " "]
  ENDIF

  RETURN

' Def_Horiz_Bar_Char
Def_Horiz_Bar_Char:

  SEROUT LcdPin, T9600,                      ' Define custom character
         [noparse][[/noparse]Define + custChar]
  FOR index = 0 TO 7                         ' 7 bytes, define 7 dotted lines
    SEROUT LcdPin, T9600, [noparse][[/noparse]dotLine]          ' Send it to the LCD
  NEXT
  SEROUT LcdPin, T9600, [noparse][[/noparse]133, DEC4 rpm]
  RETURN

' Disp_Cust_Char
Disp_Cust_Char:

  SEROUT LcdPin, T9600,                    ' Print custom character
         [noparse][[/noparse]line + cursor, custChar]
  RETURN

bill190 · 2010-03-01 00:55

Perhaps instead of DEC4, DEC

tgraz34 · 2010-03-01 01:06

Well if i do that the LCD wont clear it self and there will still be 1 zero left

Mikerocontroller · 2010-03-01 01:18

Output·four spaces and then·output your DEC value in the same location.

bill190 · 2010-03-01 01:19

Before sending the new RMP value to display, can you first send a command to clear the screen?

tgraz34 · 2010-03-01 01:51

Mike im not sure where to output those four spaces. Do you mean before RPM like this "....RPM"

bill190 · 2010-03-01 02:58

I'm just guessing because I don't know which specific LCD you have and can't look at the instruction manual for that LCD...

But maybe before this...
SEROUT·LcdPin,·T9600,·[noparse][[/noparse]133,·DEC4·rpm]

Maybe something like...
SEROUT·LcdPin,·T9600,·[noparse][[/noparse]133,·"··· "]

And instead of the above...
SEROUT·LcdPin,·T9600,·[noparse][[/noparse]133,·DEC·rpm]

If that does not work, might want to say which specific LCD you have and give a link to the instruction manual.

Or to explain this, here is a count down example which leaves the 1 there...
(Should count down from 12 to 7)

12
11
10
19
18
17

And a correction for that...
(Send spaces and it gets rid of the 1)

"· "
12
"· "
11
"· "
10
"· "
·9
"· "
·8
"· "
·7

tgraz34 · 2010-03-01 11:04

Thanks, i'm going to try using the spaces. I have the parallax 27979 LCD if your wondering.

bill190 · 2010-03-01 15:29

Ok, now that I can read the directions, I know what I am doing more...

So we have this and I was wondering what the 133 was for...
SEROUT·LcdPin,·T9600,·[noparse][[/noparse]133,·"··· "]

Looking in the directions for the LCD, it means...
133· Move cursor to line 0, position 5

So that gives us more options! Because there are more of these commands in the instruction manual...

128 Move cursor to line 0, position 0
129 Move cursor to line 0, position 1
130 Move cursor to line 0, position 2
131 Move cursor to line 0, position 3
132 Move cursor to line 0, position 4
133 Move cursor to line 0, position 5
134 Move cursor to line 0, position 6
135 Move cursor to line 0, position 7
136 Move cursor to line 0, position 8
137 Move cursor to line 0, position 9

So you could do this...

SEROUT LcdPin, T9600, [noparse][[/noparse]128, " "]
SEROUT LcdPin, T9600, [noparse][[/noparse]129, " "]
SEROUT LcdPin, T9600, [noparse][[/noparse]130, " "]
SEROUT LcdPin, T9600, [noparse][[/noparse]131, " "]
SEROUT LcdPin, T9600, [noparse][[/noparse]132, " "]
SEROUT LcdPin, T9600, [noparse][[/noparse]133, " "]
SEROUT LcdPin, T9600, [noparse][[/noparse]134, " "]
SEROUT LcdPin, T9600, [noparse][[/noparse]135, " "]

Or...

SEROUT LcdPin, T9600, [noparse][[/noparse]131, "··· "]

Depends on where position 0 is!

Experiment and see what happens...

FYI - Here are the LCD instructions. Note on page 11 it shows various characters. And one of the characters listed is blank! (Nothing). You could send that character to overwrite a zero...

http://www.parallax.com/Portals/0/Downloads/docs/prod/audiovis/SerialLCD-v2.0.pdf

Post Edited (bill190) : 3/1/2010 3:42:39 PM GMT

LCD tachometer help

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