My Slim 2AA Battery Node

[iteafreely]

As information for everyone, I suggest that if you get sockets for the ATMEGA, that you get
these:
rather than these:

The reason being that the former have a much wider gap in the middle than the later. Because of that, the .1 puff #104 monolithic multilayer 5.08mm pitch capacitors called for in the BOM fit nicely. If you use the later ones, you will need to remove material from the socket to fit them.

[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.