Sensebender Micro

tlund

Thanks for bringing this great project to the community.

I'm trying to understand the sensebender's power profile, especially the sleep current.

I have previously done some measurements with the atmega328p (pro mini) + NRF. In addition to that I have also looked at the datasheets for the other components on the sensebender.

It seems the theoretical low sleep current consumption is something like this:

* nrf24l01+    900nA
* atmega328p     5uA (with WD)
* si7021        60nA
* atsha204      30nA
* at23df512c   300nA
  =  Total     6.3uA

The SBMicro seems to draw ~50uA in sleep mode with the default configuration.

I managed to put the flash memory into "ultra deep sleep"(*), causing the total consumption to drop to ~27uA. So there is still around 20uA that is not accounted for.

I've also tried putting the atsha204 into sleep, but that did not make any difference (also confirmed by the specs).

Are there some other settings/sleep modes that have not been enabled yet? What about the atmega itself?

Do any of you have the a sensebender prototype with separate components, and can test sleep current by removing components one
by one? (Before I start cutting traces on my own sensebenders in order to zero in on the target component).

Is there something I'm missing?

Datasheets:
ATSHA204
AT25DF512C
Si7021 A20

(*) in setup(): flash.initialize(); flash.ultra_deep_sleep() <- From datasheet

tbowmo

@tlund

Interesting figures.. are you sure that you've got a genuine nrf24 chip on the radio? Could be a fake with higher power consumption.

tlund

@tbowmo

My NRF's are the same $1 nrf's listed in the mysensors store, so probably fake. But I have still measured them to draw ~900nA in powerDown.

But I think I have found the culprint now. It seems the extra 20uA is caused by Arduino 1.6.5 (it may be that my installation is faulty).

My test setup:

pro mini
nrf
a simple sketch that does gw.sleep(60s)

1st test: sketch compiled & uploaded via Arduino 1.0.5-r2: 6uA
2nd test: sketch compiled & uploaded via Arduino 1.6.5: 24uA

tbowmo

@tlund

Hmm could it be some optimization that causes the atmega to not go into deepest sleep mode?

Maybe someone should have a look at the assembler output from a build with both versions of arduino

Fabien

I'm back with bad news ... My 5th sensebender have a lot of st:fail like the first one. But now I know why !
There is only one same things between the two board which fails : The FTDI connector. It's 90° connector and pins are just below the antenna. And I think tunning is not ok.
So, when I go to work I try to remove the FTDI connector and see if connection is better !

tbowmo

@Fabien

That ftdi connector could have some effect on the antenna. I specifically made the area below the antenna empty, so that it wouldn't make any problems with the antenna.

Fabien

So now the good news. I "repair" my 1st SenseBender (only two wire but one on the ATMega) and it works (with the same radio wich failed). I remove the FTDI header and everythings is ok. So now I'm sure the problem is the FTDI header near the antenna. And be carefull, we can have the same problem with battery for example. I suppose minimal distance is about 3.2 cm (lambda/4).
But now I have a question : How can I update sketch without header (0° header doesn't fit in case). OTA ? Is ther a tutorial for OTA update with out of the box SenseBenderMicro ?

Thank for your help !

gloob

I have the FTDI headers on the opposite site and I also get this transmission errors.
I ordered a new batch of NRF24L01+ modules and will check if the problem still exists.

mvader

I have my FTDI headers on the other side as well and have no transmission errors.
I am using genuine NRF+ radios though.
could be the fakes causing a problem

tbowmo

I have a male connector on my FTDI thingie, so I just put it in the mounting holes on the micro, and hold it to one of the sides, so it makes contact.

tlund

@tbowmo

I tried uploading the sensebender sketch using 1.0.5-r2 with board config "pro mini 328 3.3V 8MHz". The si7021 doesn't work in this configuration, but I managed to get a sleep current of ~6.8uA

I can provide the binary output from the two IDE versions if someone can give me an indication where to find the build binaries.

tbowmo

@tlund

I think it's better if we can get the intermediate asm file from the compiler chain. Will look at it tomorrow evening (I have closed my computer down for the evening today)

mvader

@gbfromhb said:

@mvader
I have so far had no problems running my PIR sensors at 3.3v with the following hack.

http://techgurka.blogspot.com/2013/05/cheap-pyroelectric-infrared-pir-motion.html

You can not do this with all PIR Sensors from what I understand, but one of the ones listed in the MySensors store is what I've been using. Go down to the bottom of the article.

I just wanted to follow up and say thanks for the link/info
i was able to get that working.
surprised that they just don't offer a 3v pin.. it works great the way that link shows
Thanks again!

5546dug

Has anybody built a box for the standard Sensebender Micro with 2 AA batteries yet.
I would like to get the .stl files if so
Thanks Doug

Sparkman

@5546dug said:

Has anybody built a box for the standard Sensebender Micro with 2 AA batteries yet.
I would like to get the .stl files if so
Thanks Doug

Hi Doug,

@ServiceXP has posted this one: http://forum.mysensors.org/topic/1566/mysensors-sensebender-micro-3dp-case

Cheers
Al

Kurtsejr

Has anyone been able to "Include" it to VERA UI7, My Sensebender borad is working fine according to the output from the Arduino terminal window - it request a node id, but will not "include". I'm using the default code already installed in Sensebender Micro board.

/Kurt

hek

Yes, it works in UI7. Are you using the correct Vera-branch?

https://github.com/mysensors/Vera/tree/UI7

gloob

If somebody is looking for some Sensebenders. They are in sale currently for only 14$

http://imall.itead.cc/mysensors-micro.html

Edit:

I thought I had paid 17$ but they were initially sold for 14$. Sorry.

Fabien

I just order 4 new sensebender, NRF24L01+ (normal and PA+LNA), and Iboard for the gateway. Shiiping is quite expensive (about 31 $)

tbowmo

@Fabien

Did you choose DHL as shipping option?

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