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--- arduino:arduino_without_a_bootloader [2020/02/27 18:23] – [Hardware] mithat
+++ arduino:arduino_without_a_bootloader [2021/04/22 00:40] – [Cursed is the bootloader] mithat
@@ Line 16: / Line 16: @@
 Another reason to not use a bootloader is that the startup time is critical. The Arduino bootloader introduces about a second and a half delay between power-up/reset and running your program. Without the bootloader, your code starts running almost instantaneously.
-Yet another situation where you might not want a bootloader is if you have lowered or disabled the [[https://microchipdeveloper.com/8avr:bod|Brown-Out Detection]] so you can use every last ounce of battery juice in a portable application.((Disabling brown-out detection or lowering the threshold of detection involves [[arduino:atmega328p_arduinos_and_custom_fuse_settings|custom fuse settings]] and is beyond the scope of this article.)) Without brown-out detection, the erratic system behavior you can expect at very low voltages could cause a program jump to an arbitrary part of the code in flash storage. If you use a bootloader, this could be a jump into bootloader code. This then has the potential to start a cascade of events that leads to the bootloader overwriting your program code. If you're not using a bootloader, the code you have programmed can't be corrupted this way.((Not using a bootloader in this situation will keep the program memory form becoming corrupted, but EEPROM and other things can still be battered when the voltage falls below the minimum for a given clock frequency. The risks are described more completely in the [[http://ww1.microchip.com/downloads/en/Appnotes/doc1051.pdf|AVR180: External Brown-out Protection]] application note.))
+Yet another situation where you might not want a bootloader is if you have lowered or disabled the [[https://microchipdeveloper.com/8avr:bod|Brown-Out Detection]] so you can use every last ounce of battery juice in a portable application.((Disabling brown-out detection or lowering the threshold of detection involves [[arduino:atmega328p_arduinos_and_custom_fuse_settings|custom fuse settings]] and is beyond the scope of this article.)) Without brown-out detection, the erratic system behavior you can expect at very low voltages could cause a program jump to an arbitrary part of the code in flash storage. This could be a jump into bootloader code if the micro is using a bootloader. This then has the potential to start a cascade of events that leads to the bootloader overwriting your program code. If you're not using a bootloader, the code you have programmed can't be corrupted this way.((Not using a bootloader in this scenario will keep the program memory form becoming corrupted, but EEPROM and other things can still be corrupted when the voltage falls below the minimum for a given clock frequency. The risks are described more completely in the [[http://ww1.microchip.com/downloads/en/Appnotes/doc1051.pdf|AVR180: External Brown-out Protection]] application note.))
 There are situations apart from these where you wouldn't want to use a bootloader that you might discover as you become more experienced with Arduino and microcontroller programming. For whatever reason, if you want to explore how to upload programs to ATmega-based Arduinos without a bootloader, then read on.