2 AA batteries with step up converter to Vcc pin VS 3 AA batteries to RAW pin
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@m26872 Interesting findings! A not at all unreasonable setup either. As to AAA ... I don't know. They're less than half of an AA typically in terms of capacity usually. At the same per unit price. Still you'd probably get up to a year on 4xAAA. Or close enough. For just a few sensors I could probably live with this.
@bjornhallberg So the next exercise would be to compare the 3AA setup with the 4AAA setup? My first thought is that it could pretty even but with some different features in terms of space, duration and price.
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Don't buy the 3.3V boost / step-up listed in the "store" if you intend to run it on batteries. It has a quiescent power draw of 1mA or so (a modern boost will have 5uA o so by comparison!!), which will drain even your 2xAA batteries in well under two months for sure no matter how lean you run the rest of the circuit. Unfortunately there is no better boost that I've found for sale. You'll have to either wait for the official mysensors hardware lineup which will start with a boost circuit. It should be ready any day now? Right? :-) @axillent
Or you can run most of the sensors on just 2xAA (in series) directly, no boost or anything in-between. Sure the voltage will soon drop below 3V but it will most likely take months and most sensors as well as the nrf24 and arduino pro mini will cope with that. You wont be able to suck every last drop out of the batteries but it shouldn't be too bad. Far better than the 1mA quiescent.
If you had a boost, and limited space, you could also power your sensor node with just one AA. Like the official battery powered sensor node that is forthcoming.
If you're handy with SMD and can source a few capacitors and inductors you could always build some yourself. Texas Instruments has free samples available if you want to try. Still trying to get mine to work though :-/ I can't figure out what I did wrong here. I thought about starting thread about it but I'm holding out for the official modules.
Btw. Battery Calculator: http://oregonembedded.com/batterycalc.htm
@bjornhallberg said:
Don't buy the 3.3V boost / step-up listed in the "store" if you intend to run it on batteries. It has a quiescent power draw of 1mA or so (a modern boost will have 5uA o so by comparison!!), which will drain even your 2xAA batteries in well under two months for sure no matter how lean you run the rest of the circuit. Unfortunately there is no better boost that I've found for sale. You'll have to either wait for the official mysensors hardware lineup which will start with a boost circuit. It should be ready any day now? Right? :-) @axillent
Well, if you wanted to test now you could try the JeeLabs AA board: http://moderndevice.com/product/jeelabs-aa-power-board/
Or:
http://lowpowerlab.com/powershield/I'm waiting for the MySensors boost board tho.
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Does anyone have the spec sheet for the Chinese step up regulator? I bought a few of these to test
http://www.pololu.com/product/2561@Rek said:
Does anyone have the spec sheet for the Chinese step up regulator? I bought a few of these to test
http://www.pololu.com/product/2561My guess is that it is or is similar to the 2108A in SOT89-3 described here:
http://fullmany.com/Upload/file/ME2108%20series-E8_0.pdf
