getchar Linker error

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Read-Only Author Eric Jackowski Posted 31-May-2005 12:58 Toolset ARM	getchar Linker error Eric Jackowski I am new to programming microcontrollers, and I am just trying to write a simple program that echos back the characters to the screen. I first started off by trying to read from the serial port but then got this error: *** ERROR L104: MULTIPLE PUBLIC DEFINITIONS SYMBOL: getchar?T MODULE: C:\KEIL\ARM\LIB\CAL.LIB (getchar) DEFINED: .\XFLASH\Serial.obj (Serial) I am just using the defualt function from one of the demos: int getchar (void) { /* Read character from Serial Port */ while (!(U0LSR & 0x01)); return (U0RBR); } In main I have the following just to see if I can read in a char: char c='0'; int argsread =0; while (1) { printf ("Enter a byte\n");/ argsread = scanf("%bd",&c); printf("Arguments read: %d\n",argsread); } I tried to look up the linker error, but the SW did not have any help ability for the linker. I know it is having conflicts with the getchar defined in the cal.lib, but it does not give me this error for the putchar function. So I don't know whats going on. Can anyone help? Thanks

Read-Only Author Stefan Duncanson Posted 1-Jun-2005 03:52 Toolset ARM	RE: getchar Linker error Stefan Duncanson Things may be different for ARM, but in C51 you need to replace the function _getkey() rather than getchar() to customise the standard input functions. I'm not quite certain what you're trying to achieve with your scanf() call, but if you are trying to read in a single byte you need to use the %c format specifier. It would seem simpler to call getchar() to do this, though.

Read-Only Author Reinhard Keil Posted 1-Jun-2005 09:46 Toolset ARM	RE: getchar Linker error Reinhard Keil You need to use the INTERWORK directive. See: http://www.keil.com/support/docs/2929.htm Reinhard

Read-Only Author Eric Jackowski Posted 1-Jun-2005 09:49 Toolset ARM	RE: getchar Linker error Eric Jackowski Thanks everyone. I just had to change to using _getkey.

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