MySensors battey board revision 1.0
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@axillent
I feel like the straight man, feeding you lines :-)Seriously, it's great to have the differences listed for everybody to see.
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How's the progress with the radio?
I was thinking about the small stuff soldering, Me myself don't have that much trouble with the multi-pin chips.
For QFN (I hate them) I usually pre-solder the pads and use lot of flux and heat gun.
For TQFP I usually solder just one pin in 2 corners, and then I put a thin strip of solder along the pins and just drag my iron across. and if it's a mess, you used too much solder and to little flux :)
I hate soldering smd resistors and stuff, the smaller the more ass they get.. :P -
How's the progress with the radio?
I was thinking about the small stuff soldering, Me myself don't have that much trouble with the multi-pin chips.
For QFN (I hate them) I usually pre-solder the pads and use lot of flux and heat gun.
For TQFP I usually solder just one pin in 2 corners, and then I put a thin strip of solder along the pins and just drag my iron across. and if it's a mess, you used too much solder and to little flux :)
I hate soldering smd resistors and stuff, the smaller the more ass they get.. :P@Damme I get first success on testing soldered radio, but more tests are needed
I use similar technique for QFN and TQFP
goof flux is a mustAnd why you hate this little friendly SMD staff?) I like them. 0603 is optimal size, easy to solder, not too little.
0402 needs much more care -
I'm opening this topic for the discussion of the Mysensors board.
We are very close to production this why an open discussion is very important to fix critical things and to understand your interest on the board.
The price will very depends on volumes. But lets come to that later.
Preliminary characteristics:50x50 mm size
on board AAA battery holder
very efficient step to power up at 3.3V from any single AAA (alkaline or Ni-MH/CD)
atmega328p running at 1MHz from internal oscillator with ability to speed up to 8MHz on the fly
NRF24L01 with antenna
solar power switch, connect external solar panel 0.8-5.5V and solar will be the main power while solar voltage is higher than battery
one I2C GROVE connector which can be used as a connector to A5/A4
one GROVE analogue connector to A0/A1
one GROVE digital connector to D2/D3
high precision very low power I2C temperature sensor with ability to wake up MCU at temperature alertt
one red LEDto program you will need an external USB<->UART like you need to program pro-mini
Looks like a very nice board and the ability to also power it using a solar cell and the very efficient step up converter makes it quite interesting to me.
One question: Would it be possible to use a rechargeable AAA battery and if there is enough (solar) power, recharge the battery?
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Looks like a very nice board and the ability to also power it using a solar cell and the very efficient step up converter makes it quite interesting to me.
One question: Would it be possible to use a rechargeable AAA battery and if there is enough (solar) power, recharge the battery?
@daulagari sure you can use rechargeable AAA as power source
it is decided not to add charging function
if you will use dual power (and if your sketch will be optimal from power saving) regular alkaline can lasts for 1-2 years
at the same time rechargeable AAA because of often charging-recharging circle (every day because of solar) it can last in one year
number of recharging circles are limited and also Ni-Mh/Cd they last faster in such way because of "memory" effect -
@axillent: Still a bit puzzled as the combination of support operation from an external (solar) supply but no charging support seems not logical to me.
Understood that the number of recharging cycles of rechargeable batteries is limited but batteries still have about 10 times the capacity of supercaps so also if the capacity is reduced to 10% of the initial capacity because of the number of recharging cycles they are still a better choice.
On Wikipedia I read that charging at C/300 or even C/40 seems to be safe over long time and that can be done using a diode and resistor I think.
But ... also if there is no charging support, I am interested to buy a few ;-)
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@axillent: Still a bit puzzled as the combination of support operation from an external (solar) supply but no charging support seems not logical to me.
Understood that the number of recharging cycles of rechargeable batteries is limited but batteries still have about 10 times the capacity of supercaps so also if the capacity is reduced to 10% of the initial capacity because of the number of recharging cycles they are still a better choice.
On Wikipedia I read that charging at C/300 or even C/40 seems to be safe over long time and that can be done using a diode and resistor I think.
But ... also if there is no charging support, I am interested to buy a few ;-)
@daulagari
the logic is that none rechargeable battery can lasts for 1-2 years
rechargeable battery can lasts for 1-2 years too
and what is a reason to pay more for rechargeable one?it is theory, but it is based on deep thinking. If we will see a practical reasoning for recharging function it will be added to revision 2
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Interesting analysis.
We get into a mindset that solar + battery implies recharging the battery from solar. That is, we think of the solar as the power and the battery as a buffer for dark periods.
You are using the solar as a battery extender for a primary battery. It can run for very long periods in total darkness (much less cloudy days), but when it does get solar you can go longer between battery changes.
And your point is that the rechargeable batteries need to be changed every year or two anyway, so if you can get that long with a primary cell (cheaper and bridges longer gaps without solar), why bother?
Sounds good to me - I await practical experience. Do you yet have one or more test units accumulating data and testing the approach? On cool things about JeeLabs is that with each new design he puts up some long term test units, wirelessly logging the results. Over time he gets years worth of practical results to report and analyze.
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Interesting analysis.
We get into a mindset that solar + battery implies recharging the battery from solar. That is, we think of the solar as the power and the battery as a buffer for dark periods.
You are using the solar as a battery extender for a primary battery. It can run for very long periods in total darkness (much less cloudy days), but when it does get solar you can go longer between battery changes.
And your point is that the rechargeable batteries need to be changed every year or two anyway, so if you can get that long with a primary cell (cheaper and bridges longer gaps without solar), why bother?
Sounds good to me - I await practical experience. Do you yet have one or more test units accumulating data and testing the approach? On cool things about JeeLabs is that with each new design he puts up some long term test units, wirelessly logging the results. Over time he gets years worth of practical results to report and analyze.
@Zeph thanks for the feedback
I'm wondering on triple power sources - main is solar, buffer is super capacitor and none rechargeable as back-up
super-capacitor is a best choice for night time run while charging at daylight time
super capacitors are not cheap, but while we will have a production experience I think we will manage its price downsure it will be good to track performance. May be Henrik can think of adding some statistics logging to MyCloud service and this can be seed from the whole community in the future
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the logic is that none rechargeable battery can lasts for 1-2 years
rechargeable battery can lasts for 1-2 years tooAfter the 1-2 years the none rechargeable battery is empty and should be brought to the recycling point but my own experience is that rechargeable batteries are not gone in two years.
See Nickel–metal hydride battery#Telecommunications, it looks to me NiMH batteries can be designed for 10 year operation. Also normal available batteries claim they retain 65-70% capacity after five years in storage and like written earlier, I think we can do with 10% of the original capacity.
No problem for me if this has to wait, I can always add something myself, and yes, let logging prove what's right. Only thing I find a pity is that it will take two but probably much more year to prove things ;-)
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the logic is that none rechargeable battery can lasts for 1-2 years
rechargeable battery can lasts for 1-2 years tooAfter the 1-2 years the none rechargeable battery is empty and should be brought to the recycling point but my own experience is that rechargeable batteries are not gone in two years.
See Nickel–metal hydride battery#Telecommunications, it looks to me NiMH batteries can be designed for 10 year operation. Also normal available batteries claim they retain 65-70% capacity after five years in storage and like written earlier, I think we can do with 10% of the original capacity.
No problem for me if this has to wait, I can always add something myself, and yes, let logging prove what's right. Only thing I find a pity is that it will take two but probably much more year to prove things ;-)
@daulagari said:
After the 1-2 years the none rechargeable battery is empty and should be brought to the recycling point but my own experience is that rechargeable batteries are not gone in two years.
I've read that NiCD can sometimes do better for solar landscape lights than NiMH, because the type of cycle favors it, but often they say to plan to replace the batteries every couple of years anyway - between the charge cycling and the outdoor temperature cycling (cold and hot).
Perhaps this is different, being very shallow discharge compared to lighting. Really only testing will let us know for sure, and I'd be glad to see the results of that.
And yes, it's hard to wait a year or two for results. (It's hard to get most homebrewers to let their products age, too). But the time to start the test is now, and results will start trickling in. It used to be kind of fun when JeeLabs would post something like "Well, unit #1 is at 420 days and unit #2 is at 287 days, and here are the results so far". Sort of like slow gardening.
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Interesting!
I believe your choices are great between size and functionality for a non specific use case. -
Also interested.
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Can't give any ETA yet. We'll start with production of 500 pcs of the step-up module (to test production site). Vacations has delayed things a bit.
@hek Hi there . I am still interested . Can i pre book some pieces?
I think the 500 lot will vanish :-)
Consider approx 10 boards per interested person...
