Hi. A question from a very beginner. I successfully programmed Blink sketch into the ATtiny85 using my USBasp programmer. Now I'm trying to do the same with ATtiny2313. After compilation, I receive the message "A programmer is required for upload." I think I chose the wrong settings for the programmer in ATtiny core. If anyone has worked with ATtiny2313 and ATtiny core, I will be grateful for the hint of which settings to choose.
Got that. In version IDE 2.X, you need to use Upload using programmer. Everything works.
Hi @efimius. Thanks for taking the time to post an update with your findings!
Which version of Arduino IDE are you using? I ask because, as you found, it is true that older versions of Arduino IDE 2.x required you to use "Upload Using Programmer" when uploading via an ISP programmer. However, since version 2.3.3, it should be possible to upload to the ATtiny2313 while you have Tools > Board > ATTinyCore > ATtiny2313(a)/4313 (No bootloader) selected from the Arduino IDE menus by simply clicking the "Upload" button on the IDE's toolbar (or selecting Sketch > Upload from the menus):
Support "Upload Using Programmer by default" feature
arduino/arduino-ide#2500,arduino/arduino-ide#103Arduino IDE offers two methods for uploading sketches to a board:
- "Upload": Upload directly via the board's interface to the computer.
- "Upload Using Programmer": Upload via the ISP programmer that is selected from the Tools > Programmer menu
Some boards don't have the capability to be uploaded to via a direct interface to the computer, so it is always necessary to use an ISP programmer to upload to these boards. In order to make the use of these boards more convenient, the Arduino boards platform framework allows the board definition to be configured so that when the user triggers an "Upload", an "Upload Using Programmer" is instead triggered.
Previously, Arduino IDE 2.x did not support this "Upload Using Programmer by default" feature, meaning that an "Upload" operation would fail with an "
A programmer is required to upload" error. Support for the feature has now been added.
My version 2.1.0 and UPLOAD does not work in it. Fortunately, I tried UPLOAD BY USING PROGRAMMER and it worked. Thank you for your quick reaction. 
OK, that explains it. 2.1.0 is pretty outdated. Unless you have a specific reason for using that version of Arduino IDE, I recommend updating to the latest version 2.3.4. You can download the latest version from the links listed on the "Software" page: