When compiling the example projects the majority of the functions return the compiling error “undefined reference …”. In this modified example of the motors1 example, the function set_motors returns the undefined reference error.
#include <pololu/orangutan.h>
#define F_CPU 20000000UL // Baby Orangutan frequency (20MHz)
#include <util/delay.h>
/*
* motors1: for for the Orangutan LV, SV, SVP, X2, Baby-O and 3pi robot.
*
* This example uses the OrangutanMotors functions to drive
* motors in response to the position of user trimmer potentiometer
* and blinks the red user LED at a rate determined by the trimmer
* potentiometer position. It uses the OrangutanAnalog library to measure
* the trimpot position, and it uses the OrangutanLEDs library to provide
* limited feedback with the red user LED.
*
* https://www.pololu.com/docs/0J20
* https://www.pololu.com
* https://forum.pololu.com
*/
unsigned long prevMillis = 0;
int main()
{
while(1)
{
// note that the following line could also be accomplished with:
// int pot = analogRead(7);
int motorSpeed = 255; // turn pot reading into number between -256 and 255
set_motors(motorSpeed, motorSpeed);
int ledDelay = motorSpeed;
if(ledDelay < 0)
ledDelay = -ledDelay; // make the delay a non-negative number
ledDelay = 256-ledDelay; // the delay should be short when the speed is high
red_led(1); // turn red LED on
_delay_ms(ledDelay);
red_led(0); // turn red LED off
_delay_ms(ledDelay);
}
}
Could you try compiling an unmodified example and post the actual output, starting at the beginning? Also, please tell us what operating system you are using and how you installed the Pololu AVR Libraries.
Hi,
Im using windows 7, and i installed the libraries using the install.bat as administrator and it said installation complete with no errors.
After using the motors1 example for the atmega 328p the output was:
------ Build started: Project: AVRGCC10, Configuration: Debug AVR ------
Build started.
Project "AVRGCC10.avrgccproj" (default targets):
Target "PreBuildEvent" skipped, due to false condition; ('$(PreBuildEvent)'!='') was evaluated as (''!='').
Target "CoreBuild" in file "C:\Program Files\Atmel\AVR Studio 5.0\Vs\AvrGCC.targets" from project "c:\users\ian\documents\avrstudio\AVRGCC10\AVRGCC10\AVRGCC10.avrgccproj" (target "Build" depends on it):
Using "RunAvrGCC" task from assembly "C:\Program Files\Atmel\AVR Studio 5.0\Vs\AvrGCCLib.dll".
Task "RunAvrGCC"
make all
AVRGCC10.c
Invoking: AVR/GNU C Compiler
"C:/Program Files/Atmel/AVR Studio 5.0/extensions/Application/Avr ToolChain/bin/avr-gcc.exe" -funsigned-char -funsigned-bitfields -O0 -fpack-struct -fshort-enums -g2 -Wall -c -mmcu=atmega328p -MMD -MP -MF"AVRGCC10.d" -MT"AVRGCC10.d" -o"AVRGCC10.o" ".././AVRGCC10.c"
Finished building: .././AVRGCC10.c
Building target: AVRGCC10.elf
Invoking: AVR/GNU C Linker
"C:/Program Files/Atmel/AVR Studio 5.0/extensions/Application/Avr ToolChain/bin/avr-gcc.exe" -mmcu=atmega328p -o AVRGCC10.elf AVRGCC10.o
AVRGCC10.o: In function `main':
c:\users\ian\documents\avrstudio\AVRGCC10\AVRGCC10\Debug/.././AVRGCC10.c(27,1): undefined reference to `set_motors'
collect2: ld returned 1 exit status
make: *** [AVRGCC10.elf] Error 1
Done executing task "RunAvrGCC" -- FAILED.
Done building target "CoreBuild" in project "AVRGCC10.avrgccproj" -- FAILED.
Done building project "AVRGCC10.avrgccproj" -- FAILED.
Build FAILED.
========== Build: 0 succeeded or up-to-date, 1 failed, 0 skipped ==========
It looks like you are using AVR Studio 5, which is a beta release that does not fully support our boards. Specifically, it does not yet work with our AVR programmers or with the Orangutan X2/SVP USB interfaces. What controller and programmer do you have?
Still, compiling should work. I have not used Studio 5, so I do not know exactly what you should do to make it work, but it looks like you are not using the compilation options specified in our project file. Did you open the project file in the motors1 folder or create a new project? If you must make a new project, see these instructions.
By the way, I also noticed that in your modified program you were trying to use the avr-libc function _delay_ms(), which I believe has a maximum delay of 13 ms. You should probably just use our delay_ms() function described here.
Thanks for letting me know about avr studio 5, i have now changed to avr studio 4 and reinstalled the libraries, but unfortunetly, I still get the same outcome. It still says:
Build started 9.5.2011 at 15:07:35
avr-gcc -mmcu=atmega328p -Wl,-Map=practice2.map practice2.o -o practice2.elf
practice2.o: In function `main':
C:\Users\Ian\Documents\default/../practice2.c:27: undefined reference to `set_motors'
make: *** [practice2.elf] Error 1
Build failed with 1 errors and 0 warnings...
and this is from the code of the original motors1 example:
#include <pololu/orangutan.h>
/*
* motors1: for for the Orangutan LV, SV, SVP, X2, Baby-O and 3pi robot.
*
* This example uses the OrangutanMotors functions to drive
* motors in response to the position of user trimmer potentiometer
* and blinks the red user LED at a rate determined by the trimmer
* potentiometer position. It uses the OrangutanAnalog library to measure
* the trimpot position, and it uses the OrangutanLEDs library to provide
* limited feedback with the red user LED.
*
* https://www.pololu.com/docs/0J20
* https://www.pololu.com
* https://forum.pololu.com
*/
unsigned long prevMillis = 0;
int main()
{
while(1)
{
// note that the following line could also be accomplished with:
// int pot = analogRead(7);
int pot = read_trimpot(); // determine the trimpot position
int motorSpeed = pot/2-256; // turn pot reading into number between -256 and 255
if(motorSpeed == -256)
motorSpeed = -255; // 256 is out of range
set_motors(motorSpeed, motorSpeed);
int ledDelay = motorSpeed;
if(ledDelay < 0)
ledDelay = -ledDelay; // make the delay a non-negative number
ledDelay = 256-ledDelay; // the delay should be short when the speed is high
red_led(1); // turn red LED on
delay_ms(ledDelay);
red_led(0); // turn red LED off
delay_ms(ledDelay);
}
}
after installling avr studio 4, it does work, but only sometimes. it worked for the print function, and for the set_motors. Then when I closed avr studio and came back to it a while later the same program came up with the undefined reference error again.
