ATtiny85 - problem defining ISR(TIM0_OVF_vect)

petercj · February 21, 2022, 6:41pm

I am trying to port some working C code (compiled in Studio 7, loaded via ISP and tested on MCU) for an ATiny85 back into Arduino for a friend.

My original code uses Counter/Timer0 to generate PWM on OC0B (PB1) as I want to keep SDA and SCL pins (PB0/OC0A and PB2) free as we may need these to communicate with MCU later on.

When I try to compile code that includes a counter0 overflow interrupt in Arduino, it fails to compile.
But when I try to compile code for a counter1 overflow interrupt in Arduino, it compiles successfully.

Why is this?

In the example below, I have stripped out all but the code in question.

I have included the code and verbose compiler output for ISR(TIM0_OVF_vect) showing error. If I do this for ISR(TIM1_OVF_vect) or ISR (PCINT0_vect) for that matter, I can compile.

volatile uint8_t FLAGS = 0; // a register of flags to communicate activity between isr and main() - Bits defined as:
#define TIM 2               // flag for Timer0 overflow event 

void setup() {
  // put your setup code here, to run once:
}

ISR(TIM0_OVF_vect){   // timer overflow interrupt 
  FLAGS |= (1<<TIM);  // set flag so that main knows to execute some code 
}

void loop() {
  // put your main code here, to run repeatedly:

}

/*
 * Arduino: 1.8.16 (Windows 10), Board: "ATtiny25/45/85, ATtiny85, Internal 8 MHz"

D:\Users\Peter\Documents\arduino-1.8.16\arduino-builder -dump-prefs -logger=machine -hardware D:\Users\Peter\Documents\arduino-1.8.16\hardware -hardware C:\Users\Peter\AppData\Local\Arduino15\packages -tools D:\Users\Peter\Documents\arduino-1.8.16\tools-builder -tools D:\Users\Peter\Documents\arduino-1.8.16\hardware\tools\avr -tools C:\Users\Peter\AppData\Local\Arduino15\packages -built-in-libraries D:\Users\Peter\Documents\arduino-1.8.16\libraries -libraries D:\Users\Peter\Documents\Arduino\libraries -fqbn=attiny:avr:ATtinyX5:cpu=attiny85,clock=internal8 -ide-version=10816 -build-path C:\Users\Peter\AppData\Local\Temp\arduino_build_113847 -warnings=none -build-cache C:\Users\Peter\AppData\Local\Temp\arduino_cache_445182 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.avrdude.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17 -prefs=runtime.tools.avrdude-6.3.0-arduino17.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17 -prefs=runtime.tools.avr-gcc.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\7.3.0-atmel3.6.1-arduino7 -prefs=runtime.tools.avr-gcc-7.3.0-atmel3.6.1-arduino7.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\7.3.0-atmel3.6.1-arduino7 -prefs=runtime.tools.arduinoOTA.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.3.0 -prefs=runtime.tools.arduinoOTA-1.3.0.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.3.0 -verbose D:\Users\Peter\Documents\Arduino\ATtiny85Sample\ATtiny85Sample.ino

D:\Users\Peter\Documents\arduino-1.8.16\arduino-builder -compile -logger=machine -hardware D:\Users\Peter\Documents\arduino-1.8.16\hardware -hardware C:\Users\Peter\AppData\Local\Arduino15\packages -tools D:\Users\Peter\Documents\arduino-1.8.16\tools-builder -tools D:\Users\Peter\Documents\arduino-1.8.16\hardware\tools\avr -tools C:\Users\Peter\AppData\Local\Arduino15\packages -built-in-libraries D:\Users\Peter\Documents\arduino-1.8.16\libraries -libraries D:\Users\Peter\Documents\Arduino\libraries -fqbn=attiny:avr:ATtinyX5:cpu=attiny85,clock=internal8 -ide-version=10816 -build-path C:\Users\Peter\AppData\Local\Temp\arduino_build_113847 -warnings=none -build-cache C:\Users\Peter\AppData\Local\Temp\arduino_cache_445182 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.avrdude.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17 -prefs=runtime.tools.avrdude-6.3.0-arduino17.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17 -prefs=runtime.tools.avr-gcc.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\7.3.0-atmel3.6.1-arduino7 -prefs=runtime.tools.avr-gcc-7.3.0-atmel3.6.1-arduino7.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\avr-gcc\7.3.0-atmel3.6.1-arduino7 -prefs=runtime.tools.arduinoOTA.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.3.0 -prefs=runtime.tools.arduinoOTA-1.3.0.path=C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.3.0 -verbose D:\Users\Peter\Documents\Arduino\ATtiny85Sample\ATtiny85Sample.ino

Using board 'ATtinyX5' from platform in folder: C:\Users\Peter\AppData\Local\Arduino15\packages\attiny\hardware\avr\1.0.2

Using core 'arduino' from platform in folder: C:\Users\Peter\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.8.4

Detecting libraries used...

"C:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=attiny85 -DF_CPU=8000000L -DARDUINO=10816 -DARDUINO_attiny -DARDUINO_ARCH_AVR "-IC:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\arduino\\hardware\\avr\\1.8.4\\cores\\arduino" "-IC:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\attiny\\hardware\\avr\\1.0.2\\variants\\tiny8" "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847\\sketch\\ATtiny85Sample.ino.cpp" -o nul

Generating function prototypes...

"C:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -flto -w -x c++ -E -CC -mmcu=attiny85 -DF_CPU=8000000L -DARDUINO=10816 -DARDUINO_attiny -DARDUINO_ARCH_AVR "-IC:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\arduino\\hardware\\avr\\1.8.4\\cores\\arduino" "-IC:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\attiny\\hardware\\avr\\1.0.2\\variants\\tiny8" "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847\\sketch\\ATtiny85Sample.ino.cpp" -o "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847\\preproc\\ctags_target_for_gcc_minus_e.cpp"

"D:\\Users\\Peter\\Documents\\arduino-1.8.16\\tools-builder\\ctags\\5.8-arduino11/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847\\preproc\\ctags_target_for_gcc_minus_e.cpp"

Compiling sketch...

"C:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -Wno-error=narrowing -MMD -flto -mmcu=attiny85 -DF_CPU=8000000L -DARDUINO=10816 -DARDUINO_attiny -DARDUINO_ARCH_AVR "-IC:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\arduino\\hardware\\avr\\1.8.4\\cores\\arduino" "-IC:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\attiny\\hardware\\avr\\1.0.2\\variants\\tiny8" "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847\\sketch\\ATtiny85Sample.ino.cpp" -o "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847\\sketch\\ATtiny85Sample.ino.cpp.o"

Compiling libraries...

Compiling core...

Using precompiled core: C:\Users\Peter\AppData\Local\Temp\arduino_cache_445182\core\core_attiny_avr_ATtinyX5_cpu_attiny85,clock_internal8_b7bb48e507f447625c49e883d65f7886.a

Linking everything together...

"C:\\Users\\Peter\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-gcc" -w -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=attiny85 -o "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847/ATtiny85Sample.ino.elf" "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847\\sketch\\ATtiny85Sample.ino.cpp.o" "C:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847/..\\arduino_cache_445182\\core\\core_attiny_avr_ATtinyX5_cpu_attiny85,clock_internal8_b7bb48e507f447625c49e883d65f7886.a" "-LC:\\Users\\Peter\\AppData\\Local\\Temp\\arduino_build_113847" -lm

wiring.c.o (symbol from plugin): In function `__vector_5':

(.text+0x0): multiple definition of `__vector_5'

C:\Users\Peter\AppData\Local\Temp\arduino_build_113847\sketch\ATtiny85Sample.ino.cpp.o (symbol from plugin):(.text+0x0): first defined here

collect2.exe: error: ld returned 1 exit status

exit status 1

Error compiling for board ATtiny25/45/85.

 */

DaveX · February 21, 2022, 7:02pm

Try TIMER0_OVF_vect per https://ece-classes.usc.edu/ee459/library/documents/avr_intr_vectors/

petercj · February 21, 2022, 8:39pm

Hi Dave
Thanks for the suggestion but sadly that's not the answer. (Oh I wish it were, I even said Doh! to myself before I tested it.)
TIMER0_OVF - still gives the same error - like it's been defined before and I can't redefine it??
TIMER1_OVF works fine - but this is not the timer I'm trying to use.
My test code and the shorthand compiler error below:

volatile uint8_t FLAGS = 0; // a register of flags to communicate activity between isr and main() - Bits defined as:
#define TIM 2               // flag for Timer0 overflow event 

void setup() {
  // put your setup code here, to run once:
}

ISR(TIMER0_OVF_vect){   // timer overflow interrupt 
  FLAGS |= (1<<TIM);  // set flag so that main knows to execute some code 
}

void loop() {
  // put your main code here, to run repeatedly:

}
/*
Arduino: 1.8.16 (Windows 10), Board: "ATtiny25/45/85, ATtiny85, Internal 8 MHz"

wiring.c.o (symbol from plugin): In function `__vector_5':

(.text+0x0): multiple definition of `__vector_5'

sketch\ATtiny85Sample.ino.cpp.o (symbol from plugin):(.text+0x0): first defined here

collect2.exe: error: ld returned 1 exit status

exit status 1

Error compiling for board ATtiny25/45/85.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
 
 */

Coding_Badly · February 21, 2022, 8:42pm

Remove loop and setup. Add main. Enjoy.

But, you're on your own for managing time; millis and micros will no longer be available.

david_2018 · February 21, 2022, 10:10pm

Do you have an option to compile without millis being implemented? Seem to recall some attiny processors had that option under the tools menu.

jremington · February 21, 2022, 11:49pm

Arduino millis() uses that timer.

hmeijdam · February 22, 2022, 12:42pm

Compiles fine when you disable millis()

petercj · February 22, 2022, 9:30pm

Hi David
That's it - Timer0 is being used by this Arduino macro (which I'm not using).
I don't see an option not to include millis - I only see this for the ATtiny13.
No matter - I re-wrote the code to use Timer1 and selected OC1A as output - as it uses same physical pin.
My code now works in 'raw C' and also in 'Arduino land' - I had a minor scoping error for one of the variables I was messin' with but apart from that I'm clean and clear.

Thank you for your time and confirmation of what the problem was - now I understand the significance of with or without millis() in the device selection.

petercj · February 22, 2022, 9:33pm

Hi
Ah Ha!
Thank you.
Several posts with the same content. I switched to Timer1 and can compile and load via Arduino as ISP successfully.
Is there a guide that identifies h/w and s/w resources used by Arduino so I don't trip up again?

petercj · February 22, 2022, 9:38pm

Hi
Thank you.
Yup, seems this is the cause of my issue.
I don't see an option on my device list that allows me to select millis() as disabled.
What Additional Boards Manager URLs are you using. I'd like to load a different ATtiny85 board definition to those I have.

My URL is:

(https://mcudude.github.io/MicroCore/package_MCUdude_MicroCore_index.json,
https://raw.githubusercontent.com/damellis/attiny/ide-1.6.x-boards-manager/package_damellis_attiny_index.json,
http://drazzy.com/package_drazzy.com_index.json)

hmeijdam · February 23, 2022, 8:25am

The core I showed you is Attinycore (drazzy). It's part of your board managers URL, but it looks like you have activated another (damellis) core for Attiny.

system · August 22, 2022, 8:25am

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ATtiny85 - problem defining ISR(TIM0_OVF_vect)

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