• Three is Enough

    Kn/vD11/07/2022 at 21:10 3 comments

    Which assembling another ELLO LC1, I decided to push my luck and skip the six capacitors, normally needed for the operation of the LCD. It lives!! A second test - lives again! I am not observing any reduction in the quality of the displayed text.

    Turns out, ELLO LC1 can operate with ONLY THREE COMPONENTS (plus battery, of course) - PIC18, LCD, and the reset button, which is important to turn the system on or off.

    Just FYI to all who may want to assemble one of these :)

  • New PCBs

    Kn/vD10/05/2022 at 14:37 1 comment

    Release candidates of LC1 just arrived.

    The bottom side is with a lot of exposed ground copper now, because it turns out it massively improves the performance of the touch keyboard.

    Also, the battery hole is now a bit smaller, and the soldering rings for the capacitors - a bit wider.

    All looks fine but need to assemble one for test anyway.

  • Current progress

    Kn/vD10/04/2022 at 19:26 1 comment

    Finally managed to track down and fix a nasty memory leak which was happening when using string constants. Took a week, this thing alone!

    Below is the list of currently supported keywords and what is left to do to full release:

    Bitling BASIC interpreter
    ' comment until the end of the line
    === Data types
    INT     (also INTEGER for compatibility)
    REAL    (also FLOAT for compatibility)
    === operators
    +   -   *   /
    //  or  MOD     ' modulo
    ^               ' power
    <<              ' shift left
    >>              ' shift right
    =               ' (in statements) attribution
    ==  or  =       ' (in expressions) compare for equal
    <>              ' compare for not equal
    <   <=   =>   >
    AND   OR   XOR
    === variables
    VAR  <type>  <name>  { [dimension [, dimension...] ] }  { , <name> ... }
    ' DIM is alias to VAR for backward compatibility
    var int a, b[3,3]
    var real x, z[10,10,10]
    var string s[5]     ' array of five zero-terminated strings
    ' () are also supported in variable indexes instead of [] for backward compatibility
    === control structures
    IF  <expression>  THEN
    { ELSE }
    END IF  or  ENDIF
    FOR  <variable>  =  <expression>  TO  <expression>  { STEP <expression> }
    NEXT  { <variable> }
    WHILE  <expression>
    UNTIL  <expression>
    CONTINUE            ' valid for FOR, WHILE, and REPEAT structures
    EXIT                ' valid for FOR, WHILE, and REPEAT structures
    LABEL  <label_name>
    GOTO   <label_name>
    ' STOP is also supported and act the same way as END
    === subroutines
    SUB     <name> {  (  <type>  {  @  }  <variable>  { ,  <type>  ...  }  )  }
    FUNC    <name> {  (  <type>  {  @  }  <variable>  { ,  <type>  ...  }  )  }  {  AS  <type>  }
    RETURN  {  variable  }
    GOSUB   <sub_name(...)>      ' optional calling format for subs
    sub test1
    func average(real a, real b) as real
    sub store1(int x, int y, int @arr)
    === commands
    PRINT   { expression  { ,  expression ... } }
    DATA    expression  { ,  expression ... }
    READ    variable  { ,  variable ... }
    REWIND                      ' return to the first DATA element
    POP                         ' remove one return address from the stack
    POKE    <addr, val
    RESET                       ' restart the system
    SLEEP                       ' put the system to sleep
    INKEY   variable
    GET     variable  { ,  variable ... }
    INPUT   variable  { ,  variable ... }
    HLOC    <column>
    VLOC    <row>
    PUTCH   <ascii>
    DEFCH   <chrcode>  <byte1>  <byte2>  <byte3>  <byte4>  <byte5>  <byte6>  <byte7>  <byte8>
    SELCHT  < 1, 2, or 3 >
    CURSOR  < bit.0 blink, bit.1 enable >
    SCROLL  < bit.0 up, bit.1 down, bit.2 left, bit.3 right >
    TDREF                       ' refresh the text display (used after direct writes into TD RAM)
    WAIT    <milliseconds>
    === functions
    RND     (val)               ' parameter other than 0 first seeds the generator with the value
    ABS     (val)
    ROUND   (val)
    TRUNC   (val)
    FRACT   (val)
    LOGN    (val)
    LOGD    (val)
    EXP     (val)
    SQR     (val)               ' square root
    CBR     (val)               ' cube root
    SIN     (val)
    ASIN    (val)
    HSIN    (val)
    COS     (val)
    ACOS    (val)
    HCOS    (val)
    TAN     (val)
    ATAN    (val)
    HTAN    (val)
    COTAN   (val)
    FREE    ()                  ' return the largest free block in memory
    TDRAM   ()                  ' return the text display RAM address
    TDTDT   ()                  ' text display width
    TDHGT   ()                  ' text display height
    PEEK    (addr)              ' 0 and positive numbers: RAM address, negative numbers: ROM address-1
    ASC     (str)               ' character (first in string) to ASCII
    CHR$    (val)               ' ASCII to character (one-character string)
    VAL     (str)               ' string to number
    STR$    (val, d)            ' number to string; "d" specifies the number of digits after decimal point
    LEN$    (str)
    LEFT$   (str, count)
    RIGHT$  (str, count)
    MID$    (str, start, count)
    INSTR   (substr, str, start)
    TIMER   (value)             ' read system millisecond incremental counter; any value different than 0 first loads the counter
    === TODO:
    CLEAR  [ ALL  or  var [ , ... ] ]   ' undefine variables
    work with files
    OPEN    <filename>  as  #<variable>
    PRINT   #<variable> ,  .....
    INPUT   #<variable> ,  .....
    GET     #<variable> ,  .....
    CLOSE   <variable>
    IO port

  • Versions

    Kn/vD09/30/2022 at 08:48 2 comments

    When I was designing this board, in fact I designed three different boards - LC1 (this one) with PIC18, LC2 with AVR-DA or -DB, and LC3 with PIC24. Since I have no experience writing for AVR, and that's why started the software with this one, and porting to the PIC32 should not be a big task either. Not completely sure about the AVR one, though.

    Will release all the three at the same time soon.