David Johnson-Davies

I assume you mean verbose output during upload: ````text avrdude: Version 7.1-arduino.1 Copyright the AVRDUDE authors; see https://github.com/avrdudes/avrdude/blob/main/AUTHORS System wide configuration file is /Users/david/Documents/Arduino/hardware/ATTinyCore-2.0.0-dev/avr/avrdude.conf avrdude yywarning() warning: ATtiny841's eeprom writepage...

Verbose compiling output: ````text /Applications/Arduino.app/Contents/Java/arduino-builder -dump-prefs -logger=machine -hardware /Applications/Arduino.app/Contents/Java/hardware -hardware /Users/david/Library/Arduino15/packages -hardware /Users/david/Documents/Arduino/hardware -tools /Applications/Arduino.app/Contents/Java/tools-builder -tools /Applications/Arduino.app/Contents/Java/hardware/tools/avr -tools /Users/david/Library/Arduino15/packages -built-in-libraries /Applications/Arduino.app/Contents/Java/libraries -libraries /Users/david/Documents/Arduino/libraries -fqbn=ATTinyCore-2.0.0-dev:avr:attinyx7:optimization=size,chip=167,clock=internal_8m,pinmap=default,eesave=aenable,bod=disable,millis=enabled -ide-version=10819 -build-path /var/folders/fd/7rbn3jxx5j942sk5kn0vhb740000gn/T/arduino_build_397305 -warnings=all -prefs=build.warn_data_percentage=75 -verbose...

Sorry to add to your workload!

By the way - I generated those listings without a USBtinyISP plugged in (I left it at home) so that probably explains the "unable to open programmer" error.

Thanks - I'll update it after checking it a bit. What platform were you using it on, and what processor clock rate?

Thanks.

Here's a simple version: ````text void beep (int freq, int duration) { I2S.setAllPins(7, 5, 6, 6, 6); // sckPin, fsPin, sdPin, outSdPin, inSdPin const int samplerate = 8000; int halfwave...

You need: #include I also found I needed this: #include "soc/periph_defs.h" // Not sure why necessary It's based on the SimpleTone example which is in the ESP32 core at: /Users/david/Library/Arduino15/packages/esp32/hardware/esp32/2.0.12/libraries/I2S/examples/SimpleTone

OK I'll take a look at it this afternoon.

I've had a look at your code. However, I can't work out where the EEPROM library is that you're using. I have the official STM32 core version 1.9.0 installed, but...