ATtiny84 running at 1/8th speed - something wrong with my platformio.ini?

PlatformIO IDE
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1

SUMMARY:
My ATtiny84 is running at 1/8th speed, delay(1000); takes about eight seconds, and changing the fuses and other flags in platformio.ini seems to have no affect. Thoughts why?

DETAIL:
I’m uploading to an ATtiny84 using an Arduino Uno as a programmer. Relatively basic setup.

No matter what I do though, I can’t seem to get my clock speed right. I’m guessing it’s something wrong with the fuses or CPU but, I’m at a loss.

It’s running at 1/8th speed, so clearly 1MHz vs 8MHz is at issue here, but changing fuses seems to have no affect. Note that I can’t set f_cpu to 1000000L because the FastLED library requires a higher clock speed and won’t compile.

Here’s my platformio.ini:

; PlatformIO Project Configuration File
;
;   Build options: build flags, source filter
;   Upload options: custom upload port, speed and extra flags
;   Library options: dependencies, extra library storages
;   Advanced options: extra scripting
;
; Please visit documentation for the other options and examples
; https://docs.platformio.org/page/projectconf.html

[env:attiny84]
platform = atmelavr
board = attiny84
framework = arduino
upload_protocol = custom
upload_speed = 19200
upload_flags = 
	-C
	${platformio.packages_dir}/tool-avrdude/avrdude.conf
	-p
	$BOARD_MCU
	-P
	$UPLOAD_PORT
	-b
	$UPLOAD_SPEED
	-c
	stk500v1
upload_command = avrdude $UPLOAD_FLAGS -U flash:w:$SOURCE:i
	-U lock:w:0xFF:m
board_build.f_cpu = 8000000L
build_unflags = -DCLOCK_SOURCE=6
build_flags = -DCLOCK_SOURCE=0
board_fuses.lfuse = 0xE2
; board_fuses.hfuse = 0xDC
; board_fuses.lfuse = 0x62
board_fuses.hfuse = 0xDF
board_fuses.efuse = 0xFF
lib_deps = 
	fastled/FastLED@^3.6.0
	mathertel/RotaryEncoder@^1.5.3
	fabriziop/EEWL@^0.7.0

The project itself is open source. If you want to look at any other code, here’s the repo. Here’s the src folder commit as of the time of this writing. I do my best, but no promises on legibility :wink:

I’ve tried swapping out the fuses, with the flags commented above, and also played around with a number of other configurations using the AVR Fuse Calculator.

Bonus related issue: running “Set Fuses” directly (either the PIO menu or by command line) doesn’t work either, hitting me with an error message:

avrdude: no programmer has been specified on the command line or the config file
         Specify a programmer using the -c option and try again

Even though under upload flags I clearly have -c set to stk500v1. For giggles I tried moving the -c flag to the top of the listed upload flags, and the error turned into avrdude: ser_open(): can't open device "-b": The system cannot find the file specified.

I’m uh… in over my head here :sweat_smile:

I’ve tested on a handful of fresh ATtiny84 chips, and tried swapping out the cable, to no effect. And besides, the upload itself WORKS, it’s just at the wrong clock speed - which also makes it impossible to use FastLED, as NeoPixel / WS2812B communication requires fairly precise timing. I’m also using rotary encoders that need careful timing too… yeah. It’s been a long day.

Any idea why this isn’t working?

Thanks in advance!

2

Let’s try and folllow the documentation (https://docs.platformio.org/en/latest/platforms/atmelavr.html#fuses-programming) exactly. First of all, I’ll assume you want the “Internal 8MHz RC, no divide by 8” to get 8MHz. Rest at default.

grafik
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Create a new environment in the platformio.ini as

[env:custom_fuses]
platform = atmelavr
framework = arduino
board = attiny84
upload_protocol = stk500v1
upload_speed = 19200
board_fuses.lfuse = 0xE2
board_fuses.hfuse = 0xDF
board_fuses.efuse = 0xFF
upload_flags =
    -PCOM15
    -b$UPLOAD_SPEED
    -e

Change the “COM15” above to match your programer’s actual serial port (look in the Windows device manager or ls /dev/tty*).

Then open a PlatformIO core CLI and execute

pio run -e custom_fuses -t fuses -v

What does that output?