My Slim 2AA Battery Node

[iteafreely]

I just made a new case for a LiFePO4 magnetic sensor implementation of this. Thanks for the excellent work on this handy node design!
https://www.thingiverse.com/thing:3034907!

[gohan]

With 2 mini solar panels on the sides and an harvesting circuit, you could run it indefinitely 😁

[badmannen]

Good evening!

I had a bit of a break from this forum (approx 3-4 years...) And just got back into it . I managed to put a bootloader into my 328p-pu chip

can anyone just confirm if it is OK to use this bootloader with the version 2.0 board here.

I understand that it should run at 8Mhz to be stable . so I assumed I could use the bootloader that comes with Arduino IDE ?

I flashed this one onto the chip at the moment and will start to solder some of my boards soon. but would like to be sure that it is correct before I go too far =)

##############################################################

atmega328bb.name=ATmega328 on a breadboard (8 MHz internal clock)

atmega328bb.upload.tool=arduino:avrdude
atmega328bb.upload.protocol=arduino
atmega328bb.upload.maximum_size=30720
atmega328bb.upload.speed=57600

atmega328bb.bootloader.low_fuses=0xE2
atmega328bb.bootloader.high_fuses=0xDA
atmega328bb.bootloader.extended_fuses=0x05
#atmega328bb.bootloader.path=arduino:atmega
atmega328bb.bootloader.file=atmega/ATmegaBOOT_168_atmega328_pro_8MHz.hex
atmega328bb.bootloader.unlock_bits=0x3F
atmega328bb.bootloader.lock_bits=0x0F
atmega328bb.bootloader.tool=arduino:avrdude

atmega328bb.build.mcu=atmega328p
atmega328bb.build.f_cpu=8000000L
atmega328bb.build.core=arduino:arduino
atmega328bb.build.variant=arduino:standard

[NeverDie]

@badmannen Welcome back. The good news is that there's now a mysensors bootloader, which is even better because it allows over-the-air firmware updates for the atmega328p: https://www.mysensors.org/about/fota

[badmannen]

Daaaaang ... it is a good time to be alive and come back to this I see =) ... thanks a million to you guys that made that one .. that certainly makes changes a whole lot less painful!

[badmannen]

@neverdie Alright , that took me a couple of days of fighting with Arduino/Linux/windows/drivers/bootloaders etc etc etc but I got it all running with my updated gateway+repeater-node + mailbox-node. did not try the update function yet but surely it should work. just need one or two more repeater-nodes since I have way to thick cement walls here for this signal.

[badmannen]

OK I had some fun the last couple of days and actually got something done =D !

Managed to update my gateway and repeater-nodes to latest version and boot-loaded all nodes and future nodes so they are FOTA enabled .

So far I managed to assemble 3 nodes and after a bit of swearing and soldering and de-soldering and re-soldering I got:
1 - DHT11 TEMP / HUM node, on Battery (Slim 2AA) - surprisingly accurate actually

2 - DOOR-SWITCH - on Battery (Slim 2AA) - to be used in my mailbox, got the idea from someone here in the forums, so thank you, I don´t remember who it was since I probably read a million posts by now =D

3 - a 220V Relay switch, with the PA LN radio, and works as repeater ( runs on a NANO )

just wanted to say a huge thanks to the MySensors group and all people here on the forum for helping me get started (Had a little break for a couple of years =)

[NeverDie]

Let us know when you get it to FOTA update.

[badmannen]

@neverdie
Just tried it by mounting an "empty" 328P in the node just with the
fuses set to:
0xE2
0xDA
0xFE

and with the MYSBootloader .

Amazing ! . worked at the first try! (this time around =D )

( tried and failed a couple of times earlier, but I know I burned 0xFD instead of 0xFE so set the BOD to the wrong value, and that does not work )

[badmannen]

@neverdie Actually... I run into another problem ..

After I make a FOTA and upload a sketch . it runs as it should, no problem.

But if I try to update it again , it never tries to upload the sketch to the node.

The only thing I could find that was clever to do to make it work ok with a battery node was to use smartSleep();
which I do ... is there anything else in the code that needs to be present ?

[NeverDie]

Hopefully someone who knows can chime in.

[badmannen]

@neverdie OK, that person who knows something is now ME ! =D ... RTFM ... as always , it worked strangely enough to update ONCE with some slightly wrong Fuses set... reloaded the bootloader with soem correct fuses agian .. ( hopefully alst time .. and VOILA! now it works to update the node multiple times .. yeaa.

[NeverDie]

What were the winning fuse settings that you finally settled on using? Trust me, a year from now you won't remember, and you'll be glad you posted it.

[badmannen]

OK MY solution was actually the fuses that I said earlier . but confused myself by changing them back and forth a couple of times and downgraded Arduino to the previous version etc.

So the fuses for my barebone 328P are:

proMYSBL8.bootloader.low_fuses=0xE2
proMYSBL8.bootloader.high_fuses=0xDA
proMYSBL8.bootloader.extended_fuses=0xFE

the biggest issue I had was probably with ARduino IDE .. that one I enver manged to set the fuses ( I read somewhere it should.. but maybe I´m wrong) . Anyway it works when I set the fuses and upload it with AVRDUDESS.

(note: hello me 1 year into the future, just do what I say ! )
=)

[badmannen]

I just add another note to myself ( And anyone else that lost their hair wondering why the bootloader was lost....)

DO NOT UPLOAD SKETCH ONLY WITH USBASP ... it deletes the bootloader .
yes I know it is mentioned on the foru m.. just found it .. but I mention it again...

[badmannen]

@badmannen

and here is a good simple explanation of the fuses
http://www.martyncurrey.com/category/atmega/

[NeverDie]

FYI: If you run the ceramic resonator at 8mhz, with the zero wake up fuse setting, you can wake the atmega328p up in less than 4usec. This is a huge power savings compared to all other options.

[badmannen]

@neverdie aa thanks for the info. Might be useful for some other nodes I will do.

[NeverDie]

@badmannen You're welcome. I even measured it on an oscope just to be sure, so I'm certain it is true.

[badmannen]

This style?
€ 1,09 8%OFF | 20pcs Ceramic Resonators ZTT 4M 6M 8M 10M 12M 16M 4/6/8/10/12/16MHZ DIP-3 Crystal Frequency Element
https://s.click.aliexpress.com/e/mRfXWk8Nd