B4J Question [SOLVED] LCD on Raspberry with custom character

Fabrice La · Sep 20, 2017

Hi,
I am using this code

B4X:

Dim charE(8) As Byte
    charE = Array As Byte (0x00, 0x04, 0x0A, 0x0E, 0x11, 0x1F, 0x10, 0x0E) 'ê
    lcd.RunMethod("lcdPuts", Array(handle, "Pr t"))
    lcd.RunMethod("lcdPosition", Array(handle, 2,1))
    lcd.RunMethod("lcdChar", Array(handle, charE(8)))

and the error is :

B4X:

java.lang.ArrayIndexOutOfBoundsException
    at java.lang.reflect.Array.get(Native Method)
    at anywheresoftware.b4a.shell.ArraysUtils.getElement(ArraysUtils.java:76)
    at anywheresoftware.b4a.shell.Shell.getArrayElement(Shell.java:470)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:263)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:159)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:90)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:93)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:77)
    at b4j.example.main.main(main.java:29)
Une erreur s'est produite en ligne: 78
java.lang.NullPointerException
    at anywheresoftware.b4a.shell.Shell.runGoodChain(Shell.java:360)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:172)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:159)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:90)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:93)
    at anywheresoftware.b4a.BA$2.run(BA.java:229)
    at anywheresoftware.b4a.keywords.SimpleMessageLoop.runMessageLoop(SimpleMessageLoop.java:30)
    at anywheresoftware.b4a.StandardBA.startMessageLoop(StandardBA.java:26)
    at anywheresoftware.b4a.ShellBA.startMessageLoop(ShellBA.java:114)
    at anywheresoftware.b4a.keywords.Common.StartMessageLoop(Common.java:146)
    at anywheresoftware.b4a.shell.Shel
l.raiseEventImpl(Shell.java:303)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:159)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)

DonManfred · Sep 20, 2017

java.lang.ArrayIndexOutOfBoundsException

Fabrice La said:
Dim charE(8) As Byte
charE = Array As Byte (0x00, 0x04, 0x0A, 0x0E, 0x11, 0x1F, 0x10, 0x0E) 'ê
lcd.RunMethod("lcdPuts", Array(handle, "Pr t"))
lcd.RunMethod("lcdPosition", Array(handle, 2,1))
lcd.RunMethod("lcdChar", Array(handle, charE(8)))

charE has 8 entries. 0 to 7!! But you are trying to access index 8 (outofbounds)

Fabrice La · Sep 21, 2017

I did some modification and now other problem :

B4X:

    Dim charname1(8) As Byte 'é
    charname1 = Array As Byte (0x00, 0x02, 0x04, 0x0E, 0x11, 0x1F, 0x10, 0x0E)
    lcd.RunMethod("lcdCharDef", Array(handle, 1, charname1))
    lcd.RunMethod("lcdClear", Array(handle))
    lcd.RunMethod("lcdPosition", Array(handle, 0,0))
    lcd.RunMethod("lcdPuts", Array(handle, "Termin"))
    lcd.RunMethod("lcdPosition", Array(handle, 6,0))
    lcd.RunMethod("lcdPutchar", Array(handle, 1))

With this error :

B4X:

main._appstart (java line: 174)
java.lang.RuntimeException: java.lang.RuntimeException: java.lang.RuntimeException: Method: lcdPutchar not matched.
    at anywheresoftware.b4a.keywords.Common.CallSub4(Common.java:489)
    at anywheresoftware.b4a.keywords.Common.access$0(Common.java:460)
    at anywheresoftware.b4a.keywords.Common$CallSubDelayedHelper.run(Common.java:534)
    at anywheresoftware.b4a.keywords.SimpleMessageLoop.runMessageLoop(SimpleMessageLoop.java:30)
    at anywheresoftware.b4a.StandardBA.startMessageLoop(StandardBA.java:26)
    at anywheresoftware.b4a.keywords.Common.StartMessageLoop(Common.java:146)
    at b4j.example.main._appstart(main.java:174)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:90)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:77)
    at b4j.exa
mple.main.main(main.java:29)
Caused by: java.lang.RuntimeException: java.lang.RuntimeException: Method: lcdPutchar not matched.
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:119)
    at anywheresoftware.b4a.keywords.Common.CallSub4(Common.java:480)
    ... 13 more
Caused by: java.lang.RuntimeException: Method: lcdPutchar not matched.
    at anywheresoftware.b4j.object.JavaObject.RunMethod(JavaObject.java:129)
    at b4j.example.main$ResumableSub_finXML.resume(main.java:609)
    at b4j.example.main._finxml(main.java:352)
    at b4j.example.main._astream_newtext(main.java:216)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:90)
    ... 14 more

Erel · Sep 22, 2017

Not good:

B4X:

Dim charname1(8) As Byte 'é
charname1 = Array As Byte (0x00, 0x02, 0x04, 0x0E, 0x11, 0x1F, 0x10, 0x0E)

Good:

B4X:

Dim charname1() As Byte = Array As Byte (0x00, 0x02, 0x04, 0x0E, 0x11, 0x1F, 0x10, 0x0E)

Where does this code come from?

Based on the error message you are not calling the correct method.

Fabrice La · Sep 23, 2017

I saw in https://github.com/WiringPi/WiringPi/blob/master/examples/lcd.c:

B4X:

static unsigned char newChar [8] =
{
  0b11111,
  0b10001,
  0b10001,
  0b10101,
  0b11111,
  0b10001,
  0b10001,
  0b11111,
} ;

lcdCharDef  (lcdHandle, 2, newChar) ;

  lcdClear    (lcdHandle) ;
  lcdPosition (lcdHandle, 0, 0) ;
  lcdPuts     (lcdHandle, "User Char: ") ;
lcdPutchar (lcdHandle, 2) ;

And I saw this tool : https://www.b4x.com/android/forum/threads/tool-lcd-char-maker.67908/#content

Erel · Sep 24, 2017

This is Arduino C code.

Fabrice La · Sep 24, 2017

I know, but in the P4J you have the same : https://github.com/Pi4J/pi4j/blob/master/pi4j-core/src/main/java/com/pi4j/wiringpi/Lcd.java

B4X:

 /**
     * <p>
     * This allows you to re-define one of the 8 user-definable chanracters in the display. The data array is 8 bytes
     * which represent the character from the top-line to the bottom line. Note that the characters are actually 5×8,
     * so only the lower 5 bits are used. The index is from 0 to 7 and you can subsequently print the character defined
     * using the lcdPutchar() call.
     * </p>
     *
     * @see <a
     *      href="http://wiringpi.com/dev-lib/lcd-library/">http://wiringpi.com/dev-lib/lcd-library/</a>
     * @param handle file handle
     * @param index index value from 0 to 7
     * @param data 8 bytes which represent the character from the top-line to the bottom line
     */
    public static native void lcdCharDef(int handle, int index, byte data[]);

    /**
     * <p>
     * Write a single character of data to the LCD display.
     * </p>
     *
     * @see <a
     *      href="http://wiringpi.com/dev-lib/lcd-library/">http://wiringpi.com/dev-lib/lcd-library/</a>
     * @param handle file handle
     * @param data character data to write
     */
public static native void lcdPutchar(int handle, byte data);

And just looking how to use it ...

Erel · Sep 24, 2017

Assuming that the other methods work, I guess that you are using a different version of the native library which doesn't include this method.

Fabrice La · Sep 24, 2017

I am using the latest :
https://www.b4x.com/android/forum/threads/iot-jpi4j-raspberry-pi-gpio-controller.37493
Post 154 ...
This latest includes this methode ?

Daestrum · Sep 24, 2017

This line is probably sending an int instead of a byte - hence the method not matched error

B4X:

 lcd.RunMethod("lcdPutchar", Array(handle, 1))

You could try

B4X:

dim bytecode as byte = 0x01
...
 lcd.RunMethod("lcdPutchar", Array(handle, bytecode))
...

Fabrice La · Sep 25, 2017

I try also this :

B4X:

Dim charname1() As Byte = Array As Byte (0x00, 0x02, 0x04, 0x0E, 0x11, 0x1F, 0x10, 0x0E)
lcd.RunMethod("lcdCharDef", Array(handle, 1, charname1))
lcd.RunMethod("lcdClear", Array(handle))
lcd.RunMethod("lcdPosition", Array(handle, 0,0))
lcd.RunMethod("lcdPuts", Array(handle, "Termin"))
lcd.RunMethod("lcdPosition", Array(handle, 6,0))
lcd.RunMethod("lcdPutchar", Array(handle, charname1))

Same problem

Daestrum · Sep 25, 2017

It only wants a single byte in lcdPutchar- you gave it an array of bytes (charname1).

Fabrice La · Sep 25, 2017

Thanks Daestrum the solution is :

B4X:

Dim charname1() As Byte = Array As Byte (0x00, 0x02, 0x04, 0x0E, 0x11, 0x1F, 0x10, 0x0E)
Dim charname2() As Byte = Array As Byte (0x08, 0x14, 0x08, 0x00, 0x03, 0x04, 0x04, 0x03)
'Define the charactere in lcd
lcd.RunMethod("lcdCharDef", Array(handle, 1, charname1))
lcd.RunMethod("lcdCharDef", Array(handle, 2, charname2))
'the byte correspond to the integer you use to define the character
Dim bytecode1 As Byte = 0x01 ' for 1
Dim bytecode2 As Byte = 0x02 ' for 2

lcd.RunMethod("lcdClear", Array(handle))
lcd.RunMethod("lcdPosition", Array(handle, 0,0))
lcd.RunMethod("lcdPuts", Array(handle, "Termin"))
lcd.RunMethod("lcdPosition", Array(handle, 6,0)) 'place of the first character
lcd.RunMethod("lcdPutchar", Array(handle, bytecode1)) 'the first character is printed
lcd.RunMethod("lcdPosition", Array(handle, 7,0)) 'place of the second character
lcd.RunMethod("lcdPutchar", Array(handle, bytecode2))'the second character is printed

Problem solved

B4J Question [SOLVED] LCD on Raspberry with custom character

Fabrice La

Active Member

DonManfred

Expert

Fabrice La

Active Member

Erel

B4X founder

Fabrice La

Active Member

Erel

B4X founder

Fabrice La

Active Member

Erel

B4X founder

Fabrice La

Active Member

Daestrum

Expert

Fabrice La

Active Member

Daestrum

Expert

Fabrice La

Active Member

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