PlatformIO on Ubuntu - How to Reference COM and USB ports

Development Platforms
1

At the moment I run a Windows10 platform but I plan to migrate to Ubuntu 24.04.

Currently I variously use Arduino as ISP via a COM port, USBASP via USB port and more recently via python script pymcuprog with modified USB to serial card for writing to series 0, 1, 2 devices.

I am new to Unix.

How do I get the platformio.ini to reference the upload port I want to use?

I have PlatformIO running on an Ubuntu platform. I can compile but I do not know how to reference the COM port or USB port.

SOLUTION - if you’re using a serial card in a COM port, plug it in and do a pio device list from a PlatformIO terminal to see how Ubuntu references your device - but also check on the permissions care of the link to the post by Max Gerhardt below. (This doesn’t work for USBASP progranners)

Here’s the platformio.ini I was using:

; 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:attiny85]
platform = atmelavr
board = attiny85
framework = arduino

; device is USBASP V2.0 with updated firmware

upload_protocol = custom
; upload_port = usb *** this used to work on my Windows platform ***
upload_port = /dev/usb0
upload_flags =
-C
${platformio.packages_dir}/tool-avrdude/avrdude.conf
-p
$BOARD_MCU
-P
$UPLOAD_PORT
-c
usbasp
upload_command = avrdude $UPLOAD_FLAGS -U flash:w:$SOURCE:i

And here’s the error just after compile as it tries but fails on the upload:

Advanced Memory Usage is available via "PlatformIO Home > Project Inspect"
RAM:   [======    ]  59.8% (used 306 bytes from 512 bytes)
Flash: [==        ]  24.5% (used 2006 bytes from 8192 bytes)
Building .pio/build/attiny85/firmware.hex
Configuring upload protocol...
AVAILABLE: custom
CURRENT: upload_protocol = custom
Uploading .pio/build/attiny85/firmware.hex
avrdude: Warning: cannot open USB device: Permission denied
avrdude: error: could not find USB device with vid=0x16c0 pid=0x5dc vendor='www.fischl.de' product='USBasp'

Please could you aim me at the appropriate documentation - as I said I’m new to Unix as in, I installed it today.

If I use an Arduino Uno and hook this up via a serial cable, then do a

pio device list

I can see a /dev/ttyACM0

If I change my upload_port to upload_port = /dev/ttyACM0

the error indicates

Uploading .pio/build/attiny85/firmware.hex
avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied

avrdude done.  Thank you.

*** [upload] Error 1

So I have two issues, one is how to grant permissions but the other is both this and also how to reference my USBASP programmer if I use that - it never shows up in the device list as in pio device list

I’m making progress but v slowly.

I found this related post from Max Gerhardt but it didn’t help me.

AH - forgot to log out and back in. I can now successfully program an Attiny85 target with Arduino as ISP.

I’m still struggling with the USBASP programmer but I’ll open another post.