Sensebender Micro

[tbowmo]

@Dean

It will be programmed by the factory, with the "Sensebender micro" sketch, https://github.com/mysensors/Arduino/blob/master/libraries/MySensors/examples/SensebenderMicro/SensebenderMicro.ino

So it's plug'n'play as a sensor with temperature and humidity. You could always dump another sketch to the unit, if you want to use it for something else.

[gol]

I have also ordered a couple of boards to be able to evaulate them as soon as possible.

Just a question:

• What is the expected lifetime of the batteries if you use 2 AA batteries, the default preloaded sketch and reports the temp and humidity values once per minute?

[jeylites]

Out of curiosity, can over the air updates be implemented on Arduino Nano? I'm going to get 3 to put Sense to the test. :smiley:

[hek]

@gol

It was measured by @blacey to 0.05 mA while sleeping and 0.95 mA during transmit. @tbowmo got some higher figures but they were most probably related to running a NRF24L01+ clone.

@jeylites
Yes, have a look at the bootloader here:
https://github.com/mysensors/Arduino/tree/master/MYSBootloader
You can test OTA updates using the MYSController. It overwrites program memory in-place during boot. If communication goes down or fails during this process the node won't boot up again (you have to upload a new sketch while connected to you computer).

The sensbender has a external flash which means we can safely store the OTA firmware while normal sketch is running. When everything has been downloaded the DualOptiboot moves new firmware from flash to program memory during bootup. The code for this has been written (in development branch) but has not been tested yet (I failed handsoldering them :() .

[Dean]

Thankyou @tbowmo

[tekka]

@hek said:

@jeylites
Yes, have a look at the bootloader here:
https://github.com/mysensors/Arduino/tree/master/MYSBootloader
You can test OTA updates using the MYSController. It overwrites program memory in-place during boot. If communication goes down or fails during this process the node won't boot up again (you have to upload a new sketch while connected to you computer).

If the communication fails, the bootloader will remain "bootloading", i.e. will try to fetch a new firmware from the controller until the CRC matches - no need to upload a sketch via computer.

MYSBootloader 2.0 will have SHA signing implemented: for those nodes without ATSHA204 which need signed OTA updates :)

[jeylites]

@tekka said:

Yes, have a look at the bootloader here:
https://github.com/mysensors/Arduino/tree/master/MYSBootloader

Do I have to include those files into my sketch or just install MYS on windows and it will auto detect? In other words, do I have to make any changes to the sketch?

Is there any tutorial on MYS implementation?

[hek]

@jeylites

You should read up on what a bootloader is and how to install it.
http://www.arduino.cc/en/Hacking/Bootloader?from=Tutorial.Bootloader
Might be good to start another thread if you have more MYSController/bootloader questions,

[marceltrapman]

@hek said:

Might be good to start another thread

Nicely put :)

I would say 'please start another thread because this will never be found again and will help other as well'...

Just my 2 cents.

[rvendrame]

is 3V the absolute maximum or 3.3V is acceptable to power it? For non-battery operated sensors, it may be easier to find a 3.3V regulators instead 3V (at least in my country).

[tbowmo]

@rvendrame

absolute maximum voltage is 3.6V, above that you'll let the magic smoke out of the following components:

• Si7021
• external flash
• radio module.

Only the atmega328 and atsha204 will survive.

[rvendrame]

@tbowmo said:

absolute maximum voltage is 3.6V

But will all components work properly on 3.3V?

[tbowmo]

@rvendrame

Yes they would

[rvendrame]

@tbowmo thx a lot!

[doblanch]

I didn't find mention of it. What is the expected battery life ?
I was going to replace AA by CR123 to gain in space.
thkx

[hek]

I posted some measurements above. Hard to say a definite battery life expectation. Depends on many factors such as battery quality, send frequency and what external sensors you attach.

[doblanch]

@hek I computed that sending a value every minute with a 10 seconds of communication every minute (wakeup), the autonomy for a single 3V 1500mA CR123 lithium battery is around 1 year (312 Days). Around 2 year for a dual Lithium AA, I guess.
If there is 5 second of wakeup every minute, it's 500 days for a single cell CR123.
Purely theorical... but it gives an order of magnetude.

[doblanch]

@hek Of course it's difficult to predict, it's just to have an order of magnitude, specially if I want to use a CRV123 3V battery. I don't want to change it every 2 months. One year should be good.

[Hausner]

Would this work with a 3,7V Li-Ion 18650 cell? Because I've got a S... load from old laptops

[korttoma]

@Hausner said:

Would this work with a 3,7V Li-Ion 18650 cell? Because I've got a S... load from old laptops

@tbowmo said:

absolute maximum voltage is 3.6V, above that you'll let the magic smoke out of the following components:

• Si7021
• external flash
• radio module.

Only the atmega328 and atsha204 will survive.

Refering to what @tbowmo said and if you measure your batteries you will find that they will give more than 4V when fully charged I came to the conclusion that this is not a good idea.

However if someone has a good proposal for how these kind of batteries are best used with the Sensebender Micro I would like to know also.