My Slim 2AA Battery Node

[hek]

@m26872
Thanks for the kind donation to the MySensors project. We'll use it to develop new fun things for the community!

[AWI]

I was out of radio's, only a few "smd" types left which I mounted on the board with some patchwork ;-)

Now even more space left in the (small) housing.

[dakky]

Could u show a screen for the lockbits too? I have never set them before and need some guidance :D thanks

Dakky

[m26872]

@dakky Done.

[Cliff Karlsson]

Is this what you used to burn the bootloader?

USB-programmer-AVRISP-mkII-mk2-clone-ATMEL-AVR-New

[m26872]

I use this. Maybe not so expensive when I bought it 15 months ago, but still. I remember I was mad after I'd failed a lot with avrdude and cheaper tools (uno).

[martkrui]

Just received my boards from DirtyPCB :smile:
Enough for 10x3=30 sensors... :scream: The boards look nice. I think I can even skip the R&C's if I use the internal VCC measuring method but I'll have to scan the thread for that.

[m26872]

@martkrui R1 and C2 are mandatory if you intend to use the 6 pin FTDI port (I think you do). C3 (ARef - Gnd) is primarily for when you use Adc external ref, but (if I remember correct) it stabilizes the Adc in general. C1 (Vcc - Gnd) is just the "near chip supply input capacitor" and could probably be left out if there are some other caps near the nRF.

[bjacobse]

@dakky said:

Could u show a screen for the lockbits too? I have never set them before and need some guidance :D thanks

Dakky

I use ubuntu, and a tiny USB, so after I have flashed my arduino board, I run this avrdude command, that will run until battery is low

avrdude -c usbtiny -p m328p -U efuse:w:0x07:m

I have bought usbtiny from this guy:
http://www.ebay.com/itm/USBtinyISP-V4-AVR-ISP-Programmer-Reliable-Plastic-Enclosure-/330824700564?hash=item4d06b05294

[ahmedadelhosni]

@m26872 Hi again. Just a small update regarding rotating the nrf.

I decided that in my designs I'll need the straight and rotated version, thus I'll design a small board to map the pin outputs like the image below. It will be above the ICSP pins but I really don't care about re flashing.

I'll order the board as soon as I finish pcb layout of some other boards and ship all at once.

Thanks.

[m26872]

@ahmedadelhosni You know that the nRF pins are not centered? That means if you rotate it like this it will no longer be straight above the "slim node motherboard".
What height do you expect it to be?

[dakky]

Another "noobish" question:
When using this bootloader, one cycle takes 8 seconds? What happens, if for example, a switch is pressed between? does this sensor detect this?

[m26872]

@dakky Plz correct me... but I guess you're talking about the Avr sleep cycles? I don't know what that's got to do with the bootloader or this thread. I think it's related to interrupt, timers, mysensors and arduino lowpower library. The sleep cycles shouldn't be something to worry about if you're using the "sleep" function as in MySensors API.

[dakky]

@m26872 hmm you're right. maybe this is a too generic question to be discussed here. pardon me.

[martkrui]

I had a bit of an issue getting things going as I've never played with the fuses before. Maybe this can save someone else some time. If I'm doing something silly here please correct me. :sweat_smile:

[DISCLAIMER] this worked for me. Use at own risk[DISCLAIMER]

Executed these commands from the subfolder \hardware\tools\avr\bin of my local arduino IDE.
Connected the board ICSP using an USBASP with the latest firmware. Change the "-c usbasp" part if you connect using something else.

Flash bootloader

avrdude -C ../etc/avrdude.conf -c usbasp -B5 -p ATmega328P -U flash:w:..\..\..\arduino\avr\bootloaders\atmega\atmega328_1a.hex

Set fuses

avrdude -C ../etc/avrdude.conf -c usbasp -B5 -p ATmega328P -U lfuse:w:0x62:m -U hfuse:w:0xDE:m -U efuse:w:0x07:m -U lock:w:0x2F:m

I think the B5 was crucial as it slows things down a bit. The bootloader (atmega328_1a.hex) is the one mentioned in the first post. I also added the part in the boards.txt of the arduino IDE.

Now I can connect the board to the FTDI and upload and run sketches without issues.

On to the next step :smiley: :+1:

[dakky]

I am not so really skilled in transferring a wiring diagram to "real live". Is this the correct implementation for battery measuring?

[m26872]

@dakky First, the "normal" battery monitoring to this node is to use the internal method by, if you like, using the vcc library. Measuring Vcc with external voltage divider makes not a lot of sense. The external voltage divider is useful when measuring e.g. raw battery voltage to some voltage regulator.
Second, I think you've switched A0 and Gnd in your drawing.

[dakky]

hurm did i switch them?
Concerning the method: hmm ok. I just thought, that the one recommenced in the build section of mysensors should be the "correct" one.

EDIT: Hrhr @Yveaux vcc lib is cute :D workd out of the box ;) thx

[arnoldg]

Is there some one who have lying around several boards, who can share them with me.
i'm from the netherlands, and for now i only need 5 to 6 boards, not 30 :)

so i hope i could take over a couple from someone.

[AWI]

@arnoldg send me a pm...