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Topic: atmega328p - fuse settings to ensure brown out detection at 2.7v (Read 2 times) previous topic - next topic

baltazgt

So, I've bootloaded my atmega328p with a suitable 3.3v 8MHz bootloader (ATmegaBOOT_168_atmega328_pro_8MHz.hex).  It works fine.  But I am about to run the chip from a 3.7v lipo (hence this new bootloader) and I want to make sure it has BOD at 2.7v.  I have googled around this, but can't at the moment find the answer to this question: what should the fuse settings be to have BOD at 2.7v?  Or how do I work the answer out?  (I have looked at http://www.engbedded.com/fusecalc/ but I cannot make head/tail of it).

The current settings (from the boards.txt file) are:
diecimila328.bootloader.low_fuses=0xff
diecimila328.bootloader.high_fuses=0xdd
diecimila328.bootloader.extended_fuses=0x00

Thanks in advance,

Ben

Coding Badly

You're using fuse settings for a 168 processor.  Try starting with settings for a 328P processor.

baltazgt

#2
Mar 06, 2011, 11:37 pm Last Edit: Mar 06, 2011, 11:39 pm by baltazgt Reason: 1
I cut and paste the wrong section from boards.txt.  The current settings are:
pro328.bootloader.low_fuses=0xFF
pro328.bootloader.high_fuses=0xDA
pro328.bootloader.extended_fuses=0x05

Does that help with an answer?

Ben

Coding Badly

I'd add "Preserve EEPROM memory through the Chip Erase cycle; [EESAVE=0]"...

Quote
pro328.bootloader.low_fuses=0xFF
pro328.bootloader.high_fuses=0xD2
pro328.bootloader.extended_fuses=0x05


BOD at 2.7 V was and is enabled.

baltazgt


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