Summary of ARDUINO NANO MEMORY UPGRADE WITH NO SOLDERING
Design Build Destroy reclaimed about 1.5 KB of program space on some Arduino Nano boards by installing the Optiboot bootloader and adjusting fuse settings. Some Nano variants reserve a large bootloader area unnecessarily; Optiboot needs much less. Reprogramming requires an external programmer or another Arduino to avoid bricking the board. Uno boards already ship correctly with Optiboot. Results vary by Nano clone and age, and the same method can apply to other older Arduinos supported by Optiboot.
Parts used in the Arduino Nano memory upgrade:
- Arduino Nano (target board)
- Another Arduino board used as an ISP programmer or a dedicated AVR programmer
- USB cable for connecting the programmer Arduino or dedicated programmer to a computer
- Wires or jumper cables to connect programmer to Nano ISP headers
- Computer running Arduino IDE or appropriate flashing software
Ok, we’ll come clean. [Design Build Destroy] didn’t really add any memory to his Arduino Nano. But he did get about 1.5K more program space when compared to the stock setup. The trick? On some Nano boards and clones, the bootloader is set to use a large block of reserved memory, but Optiboot only requires a fraction of that reserved memory. By reprogramming the bootloader and changing the configuration fuses, you can reclaim that unused memory.
Of course, you can’t easily overwrite the bootloader and fuses over the serial port to prevent you from bricking your device. The video below shows how to connect another Arduino to do the programming. You could also use any dedicated AVR programmer you happen to have. Oddly, the Uno already uses Optiboot with the same processors, and is set correctly and the video shows the differences in the configuration between the two in their default state.
Of course, depending on where you get your Nano devices and their age, you may already have this set up at which point you won’t gain anything, but you should be able to easily tell if you need to go through the steps or not. The same trick will probably work with any older Arduino boards you have laying around if Optiboot supports them. What can you do with the extra memory? Maybe speech recognition?
Source: ARDUINO NANO MEMORY UPGRADE WITH NO SOLDERING
- What is the memory gain from this procedure?
About 1.5K of additional program space compared to the stock setup on affected Nano boards. - Why does this memory gain occur?
Some Nano bootloaders reserve a large bootloader area while Optiboot requires much less, so reprogramming reclaims the unused reserved memory. - Can I reprogram the bootloader over the serial port?
No, you cannot easily overwrite the bootloader and fuses over the serial port; an external programmer or another Arduino is used. - What hardware is used to program the Nano bootloader?
The video shows using another Arduino as the programmer, but you can also use any dedicated AVR programmer. - Do all Nano boards benefit from this upgrade?
No, some Nano boards or clones already have Optiboot and correct fuse settings, so they will not gain additional memory. - Does the Uno require this change?
No, the Uno already uses Optiboot with the same processors and is set correctly by default. - Will this method work on other Arduino boards?
Possibly; the same trick should work with older Arduino boards if Optiboot supports them. - What can I do with the extra memory?
The article suggests possibilities such as adding speech recognition, but does not detail specific projects.
