Why burn the bootloader? You're wasting 1.5 seconds of boot time that the bootloader takes to boot the chip. Instead burn the HEX file directly to the chip, your chip will start the firmware immediately super fast.
Great video! Clear and easy to understand, thank you 😀 Just one thing I am unsure about. If you burn a bootloader, then upload a sketch with the programmer, doesn't this wipe the bootloader?
Thanks for the comment. No, uploading a sketch does not wipe the bootloader. Both the sketch and the bootloader are stored in the flash memory on the chip. The sketch is stored at the front section of the flash memory, and there is an special area at the end of the flash memory (about 512 bytes) which is reserved only for a bootloader.
Programmer - DigiKey $7.77 USD - Search for "Pololu 2183-3172-ND" Base - AliExpress $10.38 USD - Search for "SZYTF TQFP32 QFP32 TO DIP32 IC Programmer Adapter" The base comes with a DIP adapter. I cut mine off so that it can span across 2 breadboards. Otherwise it covers most of breadboard connections.
Both the Atmega and the Programmer are powered from the breadboard power supply. Pin VCC on Pololu AVR programmers are set as an input by default. (This is different from video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-VVK0aYcrnQc.html where the programmer powers the circuit).
I recommend the ATMEGA328P-AU microcontroller. They cost about $2 each and can be easily programmed with Arduino IDE. Here's the link to Digikey: www.digikey.com/en/products/detail/microchip-technology/ATMEGA328P-AU/1832260 There are other SMD Atmega MCU's but I haven't been able to program them with the Arduino IDE. Good luck!
Yes, the MOSI and MISO connections are a type of serial interface. However, I don't think you can program the Atmega directly to the serial pins without a programmer.
