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9 years, 2 months ago.
The example code is giving me compiler error 20 and I have no idea why
I literally just imported the library exactly as it is, updated the mbed repository, and it gave me this: http://imgur.com/rZs0YTo
Errors contained in image: Error: Identifier "p15" is undefined in "main.cpp", Line: 6, Col: 14 Error: Identifier "p16" is undefined in "main.cpp", Line: 6, Col: 19 Error: Identifier "p17" is undefined in "main.cpp", Line: 6, Col: 24 Error: Identifier "p18" is undefined in "main.cpp", Line: 6, Col: 29 Error: Identifier "p19" is undefined in "main.cpp", Line: 6, Col: 34 Error: Identifier "p20" is undefined in "main.cpp", Line: 6, Col: 39
Code used:
<code>
- include "mbed.h"
- include "TextLCD.h"
TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD20x4); rs, e, d4-d7
int main() { lcd.printf("Hello World!\n"); } </code>
Compiler error 20 tells me "The compiler doesn't recognize the name of a variable or class you are trying to reference", The class is referenced in TextLCD.h;
<code> class TextLCD : public Stream { public:
/ LCD panel format */ enum LCDType { LCD16x2 /< 16x2 LCD panel (default) */ , LCD16x2B /< 16x2 LCD panel alternate addressing */ , LCD20x2 /< 20x2 LCD panel */ , LCD20x4 /< 20x4 LCD panel */ };
/ Create a TextLCD interface
- @param rs Instruction/data control line
- @param e Enable line (clock)
- @param d0-d3 Data lines
- @param type Sets the panel size/addressing mode (default = LCD16x2)
- / TextLCD(PinName rs, PinName e, PinName d0, PinName d1, PinName d2, PinName d3, LCDType type = LCD16x2);
- if DOXYGEN_ONLY / Write a character to the LCD
- @param c The character to write to the display
- / int putc(int c);
/ Write a formated string to the LCD
- @param format A printf-style format string, followed by the
- variables to use in formating the string.
- / int printf(const char* format, ...);
- endif
/ Locate to a screen column and row
- @param column The horizontal position from the left, indexed from 0
- @param row The vertical position from the top, indexed from 0
- / void locate(int column, int row);
/ Clear the screen and locate to 0,0 */ void cls();
int rows(); int columns();
protected:
Stream implementation functions virtual int _putc(int value); virtual int _getc();
int address(int column, int row); void character(int column, int row, int c); void writeByte(int value); void writeCommand(int command); void writeData(int data);
DigitalOut _rs, _e; BusOut _d; LCDType _type;
int _column; int _row; };
- endif </code>
Maybe my programming is rusty, and this is probably something really obvious, but I'm just not getting what is wrong. Can anyone help? Thanks!
Question relating to:
2 Answers
9 years, 2 months ago.
It looks you are using the NUCLEO-F103RB board.
The pin names, p15..20, are for the LPC1768 board.
Why don't you try the pin names of the NUCLEO-F103RB board, such as Px_x, Dx or Ax?
That did it, thanks! I appreciate the help, that was driving me nuts. I'm still very new to microcontrollers, and I had just assumed that the names were variables and didn't matter what they were named, I didn't realize that they were keywords for the various pins and specific to each board. My project now moves on!
posted by 22 Sep 2015