My Slim 2AA Battery Node

[GertSanders]

@frenchclem
Just to confirm: 35mm is the height with the small radio.
Using the larger radio (with PA+LNA) you need 41mm height
Without battery holders, and the small radio, the height is 22 mm
Width is 25mm for AAA battery holders mounted, 33mm for AA battery holder, and length is 53mm (AAA batteries) and 58mm (AA batteries)

[m26872]

v1.2 tested and working. But the design of crossing R1 and C2 was a horrible choice - it's impossible to fit both nicely under/inside the uC socket. Perhaps possible with a 1/8W R1, but otherwise R1, C2 or both must be placed on bottom side.

Good news is that all versions and orders are OK apart from this little inconvenience.

I'll try to make a better version ASAP.

[AWI]

@m26872 I have assembled 6 boards now and am very happy with the design. I use strips as a socket for the Atmega. This leaves enough room for components under it. Also made one with SPI connector. Works perfect! Thank you for sharing the design and instructions.

[m26872]

@AWI Great idea with the strips! And thanks for verifying (v1.2?).

[m26872]

I've now ordered yet another prototype version (1.4):
http://dirtypcbs.com/view.php?share=13310&accesskey=58c87fe605eb91958938f70b5efc8629

Eagle brd-file.

Photo here.

[m26872]

I bought a few enclosures... "mini trunking" seems to be the correct term. This time it was ABS and a little more clear white colour and glossy finish. I think I spent around 2hrs cutting them nicely into >200pcs. 50% 23cm and 50% 19cm lengths.

[Didi]

You want to make your town mysensors :joy:

[hek]

@m26872
200pcs!! What the heck are you up to?

[AWI]

@m26872 I think I used version 1.1? Did you change any of the wiring in the newer versions?

[m26872]

@hek
hehe, I had a hunch it'd be spectacular. Let's just say that I aim to have a few single sensor/purpose sleeping nodes, but probably not 200. At least not in a while.

[m26872]

@AWI Ops sorry, I meant v1.0. I see the larger pads in your pics. The routing is a little different to 1.2 and 1.4. Mostly related components under the uC.

[ar91]

Very nice design. Any video on installation of bootloader with various settings described in the original post?.

[m26872]

@ar91 Thx. Sorry no. I don't know of any and I'm too shy to do it myself.

[ahmedadelhosni]

Great idea using this housing.

Why didn't you use CR batteries to decrease size ?
http://www.digikey.com/product-detail/en/CR1220/P033-ND/269740

[mfalkvidd]

2AA batteries have approximately 2000mAh capacity. CR1220 has 35mAh. So for the same capacity, more than 50 CR1220 would be needed. That wouldn't save space :)
But CR1220 has lower self-discharge so they can be a good alternative for things that are really low-power, or don't need long battery life.

[m26872]

@ahmedadelhosni I've read a few reports from people with radio module issues after some time on CR "coin cell" batteries. The expected battery life time then doesn't match the result. I think you can find references by searching.

[martkrui]

m26872, I just wanted to say thank you for your work on this project and for sharing it with everybody. :+1:
I've just ordered the ATMEGAs to build 5 nodes.
How confident are you about the V1.4 PCB ? If you don't see any issue with them at this point I think I'll take the whopping $14 risk :yum:

[ahmedadelhosni]

Aha..now I understood the reason. Thanks

[m26872]

@martkrui I'm not confident until I've tested one, but usually errors can be fixed with some ugly mods if necessary. ;-)

BTW I added to the info that any/every DirtyPCB money from this share will be donated to MySensors.org.

[betonishard]

Like the board and ordered it. Can you also post exactly the capacitor types? Keep up the good work.