My Slim 2AA Battery Node

[m26872]

@Harrdy said:

I see u don't use a external 8mhz quarz. Because any technical reasons (=low current?) or for reasons of space?

Low power, low cost, less space, less work. Stability might be an issue at different ambient temperatures etc.

[m26872]

Added a boardhouse link if anyone would like to order the board straight from there (thx @AWI). Couldn't see any cons.
I think it's enough tested, but personally I'd wait for a tested v2.0 or make suggested improvements myself first.

[ahhk]

Hi,

great job! I think i will use your board to for small window -sensors.
But one question: i cannot upload sketches via arduino-ide when the 1mhz bootloader is flashed. i checked the wires and everything else and i tested a 8mhz/internal bootloader - works fine. but the 1mhz-bootloader just does not accept uploads?

[m26872]

@ahhk There's also the precompiled bootloader for 4800 baud in the link above. Did you try that one too? I think 9600 baud was maximum serial speed at 1MHz. Lower should be safer.
Or what do you mean with "does not accept uploads"? Is it locked?
Double checked boards.txt settings?

[ahhk]

Hi,

i can upload via RX/TX with arduino IDE with the 8mhz/internal bootloader. but if i flash the 1mhz bootloader from the link above (atmega328_1a.hex), i cannot upload the same way...

TX/RX is connected correctly. I can upload a sketch via "Upload with programmer" and receive and transmit characters with 9600baud. tested with the example-sketch "SerialEvent".

IT is a brand new 328P - not locked...

boards.txt shows

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

apm96.name=APM Optiboot internal 1MHz noBOD 9600baud

apm96.upload.tool=avrdude
apm96.upload.protocol=arduino
apm96.upload.maximum_size=32256
apm96.upload.speed=9600
apm96.bootloader.tool=avrdude
apm96.bootloader.low_fuses=0x62
apm96.bootloader.high_fuses=0xde
apm96.bootloader.extended_fuses=0x07
apm96.bootloader.path=optiboot_v50
apm96.bootloader.file=atmega328_1a.hex
apm96.bootloader.unlock_bits=0x3F
apm96.bootloader.lock_bits=0x2F
apm96.build.mcu=atmega328p
apm96.build.f_cpu=1000000L
apm96.build.core=arduino
apm96.build.variant=standard

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

i didnt try the 4800baud bootloader until now....i will do now...

[m26872]

@ahhk Reset issue? Maybe try other startup times (low fuse 42h or 52h), other usb2serial or adjust reset R and C.

[m26872]

For info. I've prototyped and ordered a slightly improved version of the pcb. Note that this is UNTESTED and experimental.
Eagle brd-file and board house link. Use it for inspiration. Don't expect it to be and tested until next month at least.

[mfalkvidd]

Great work @m26872
Thanks for sharing!

[frenchclem]

Really great idea @m26872 !!
I'm waiting for the V1.2 test and review before ordering some boards on DirtyPcb.
One Tip/question : have you thought on panelizing your slimnode, because we could easily fit 3 board on the 5X5 limitation ? I also think that DirtyPCB would even process the break routing to ease board separation.

[m26872]

@frenchclem
AAMOF I ordered a panelized version just a few days ago. I'm completely new to all this, so I leave no guarantees...
Here's the brd-file.

Edit 3/12: Boardhouse link removed (the panelized version of v1.2 contains a faulty via between D13 and SCK.)

[frenchclem]

I guess if you ordered panelized version, you have tested the V1.2 ? Would you mind sharing the schematics also please ?
I'm also very new to this, I've never ordered PCB on Dirtypcb, how long does it takes to arrive in Europe ?

[GertSanders]

Delivery times depend mostly on shipping time. DirtyPCB have their boards made usually within a week after uploading the files. But shipping can take 3-4 weeks to get to Europe.

[m26872]

@frenchclem
No I actually ordered before I got the first sample, due to the delivery time. But now (just a day after) I got the first v1.2. Delivery time was 4 weeks (to Sweden). Soon tested...

I don't think there are any changes to the already published schematics.

[frenchclem]

@GertSanders @m26872
Thanks guys for the good work I just ordered your boards
Will definitely let you know how things goes

GertSanders, did you find a nice box for your board + battery ?

[GertSanders]

@frenchclem Not yet, the height is indeed the limiting factor. I'm now looking for a small box that can hold the sensor on it's side. SO for the moment the sensors are scattered around the house without a box around them (usually in places where the cat does not go or could find them).

[frenchclem]

@GertSanders thats what I was worried about. What is the height of the sensor + battery ?

[GertSanders]

@frenchclem
I can not measure that now (at work), but I guess around 35mm if batteries are mounted on he bottom. By using the extrnal (JST connector) power option, the height of PCB, processor and radio is around 22mm I think.

Most boxes have an internal clearance of around 20-25mm.
Some boxes have 40mm internal clearance and are good in height, but those are usually also to long and wide for my taste.

@m26872 's board certainly is lower, since batteries are not on the bottom but in the axis of the board. The radio is also directed away from the processor on his board, so it can be mounted lower (directly on PCB instead of on a header). I really like that concept, since it will fit the plastic cableducts made by Legrand:
http://www.ecataleg.be/fr/categorie/3020/moulure-et-goulotte-murale-en-pc-abs-sans-halogene

[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.