Clean looking sensor node
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@NeverDie said:
That's good input, as I haven't yet tried running it on a button cell. Is a button cell alone just not able to keep up with the Tx load? I had wanted to avoid button cells altogether, but even an AAA battery has too wide a diameter to fit in this enclosure.
No it can't keep up with it without a serious voltage drop, especially at startup and with RFM radio. A 100µF ceramic capacitor (and sleep between successive tx in your code) should be enough from what I read from scalz who made a few boards with button cell + RFM.
I just uploaded version 0.2 of my dedicated board to Seeed, it should be just the right size this time :) Led is in front of the led window but on USB side I don't have anything, it's just a vent.
For the black tape I don't remember having so much pain to remove it, maybe it's different between enclosures, I will tell you when I receive the next one. -
On my medium node, I found that if I used right-angle FTDI header pins and if I splayed the antenna and the Temp-humidity-pressure sensor out horizontally, then the overall thickness was low enough that I could fit it inside the OP's enclosure.
Also, I think that if, rather than clipping the LED's legs after soldering it close to the board, I instead left the LED legs long, then I could bend it over and have it pointed at the LED window on the OP's enclosure, to maximize its visibility outside the closed enclosure. So, on a future version, I'll try that. -
After a long-wait, I received my so called "tabbed" CR2477 batteries today from China via AliExpress. According to the seller, they would look like this:
and so that is what I was expecting. Instead, what the seller sent me was:
which obviously has no tabs. :cry:Anyhow, the second photo shows the depth of the battery in relation to the OP's case. It looks to me as though with tabs it likely would have been too thick for the cover to snap back on the OP case.
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@NeverDie
:open_mouth: not cool
I hope your 2477 will work well ;)
my little xp about coincells showed me that i can't trust ali coincells.. well i tried only few orders, but those wasted my time searching for bugs whereas batt were discharged and didn't check this in first place as i was using fresh ali coincells. I was thinking it couldn't be that! Then i checked their voltage in case...and was surprised!
Changing for good and strong coincell was day&night.if it can help you to not run in dumb issue, for future :)
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@NeverDie
:open_mouth: not cool
I hope your 2477 will work well ;)
my little xp about coincells showed me that i can't trust ali coincells.. well i tried only few orders, but those wasted my time searching for bugs whereas batt were discharged and didn't check this in first place as i was using fresh ali coincells. I was thinking it couldn't be that! Then i checked their voltage in case...and was surprised!
Changing for good and strong coincell was day&night.if it can help you to not run in dumb issue, for future :)
@scalz said:
@NeverDie
:open_mouth: not cool
I hope your 2477 will work well ;)
my little xp about coincells showed me that i can't trust ali coincells.. well i tried only few orders, but those wasted my time searching for bugs whereas batt were discharged and didn't check this in first place as i was using fresh ali coincells. I was thinking it couldn't be that! Then i checked their voltage in case...and was surprised!
Changing for good and strong coincell was day&night.if it can help you to not run in dumb issue, for future :)
Urban Dictionary: "get shanghaied"
www.urbandictionary.com/define.php?term=get shanghaied
Top Definition. get shanghaied. verb, ditransitive, passive (with to Be or to Get). to be swindled, cheated, lied to, robbed, stolen from, duped, conned, deceived.Not sure what I'll do with the "non-tabbed" batteries. Shipping costs between the US and China are asymmetric, and it would probably cost me more in time and money to ship them back with tracking to the seller than I would get in a refund. Oh well, I guess I'll be buying batteries from Digikey in the future. It will cost twice as much, but at least I'll get the real thing.
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I just now ordered this CR2460 battery from Digikey: http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=212190252&uq=636150784616350020
It's a bit thinner and should have a better chance of fitting inside the OP case. -
I just now ordered this CR2460 battery from Digikey: http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=212190252&uq=636150784616350020
It's a bit thinner and should have a better chance of fitting inside the OP case.Epilogue: I get a call from Digikey to tell me that they can't ship the button cells by first class mail because they contain lithium. Mind you, I only ordered 3 of them. Instead, they can only be shipped by either UPS ground or FedEx ground, both of which will cost me about $10 for the shipping alone. :grimacing: Yet, USPS apparently had no trouble delivering the CR2477 button cells from China using ePacket delivery. Argh, it's all just ridiculous!
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Epilogue: I get a call from Digikey to tell me that they can't ship the button cells by first class mail because they contain lithium. Mind you, I only ordered 3 of them. Instead, they can only be shipped by either UPS ground or FedEx ground, both of which will cost me about $10 for the shipping alone. :grimacing: Yet, USPS apparently had no trouble delivering the CR2477 button cells from China using ePacket delivery. Argh, it's all just ridiculous!
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@NeverDie no, USPS are not ok with that. http://pe.usps.gov/text/pub52/pub52c6_004.htm#ep270347
@mfalkvidd said:
@NeverDie no, USPS are not ok with that. http://pe.usps.gov/text/pub52/pub52c6_004.htm#ep270347
Not that it matters, but I wonder why is it acceptable for lithium batteries to be shipped installed in equipment, but unacceptable if not installed?
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@mfalkvidd said:
@NeverDie no, USPS are not ok with that. http://pe.usps.gov/text/pub52/pub52c6_004.htm#ep270347
Not that it matters, but I wonder why is it acceptable for lithium batteries to be shipped installed in equipment, but unacceptable if not installed?
@NeverDie my guess is that the rulemakers took a pragmatic approach. Banning batteries in equipment might have been too hard, which could have brought down the entire proposition. So they opted for rules that are less safe than total ban, but more safe than no rules at all.
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@NeverDie my guess is that the rulemakers took a pragmatic approach. Banning batteries in equipment might have been too hard, which could have brought down the entire proposition. So they opted for rules that are less safe than total ban, but more safe than no rules at all.
My two cents :D
Batteries inside equipments are protected from shock by said equipment, shocks/bending beeing one of the main reasons for battery fires.
It could also be related to the "density" of batteries. Having one battery burning inside an equipment will slow down the propagation of the fire and is relatively easy to deal with a fire estinguisher.
Having a fire in one battery that will propagate to other batteries shipped together is a nightmare.But I'm surprised they apply this rule (that I thought were made to deal big rechargeable batteries) to a bunch of button cells
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LOL. This is the ultimate catch-22: I can't mail the falsely advertised batteries back to China, even if I wanted to! The only way to do it would be to first install them in some equipment and then ship the equipment, but then they would be used batteries and no longer new, so the seller could refuse a refund on those grounds. Since returning them is impossible, maybe I can appeal to Ali Express for a refund without returning them. This is becoming entertaining.... A refund from Ali Express would almost cover the cost of shipping from Digikey.
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I just received the white version and it's gorgeous ! Ordering bunch now to put everywhere in the house :D
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Link is here but unfortunately it says "no more available" :(
Found some here at 3€ :
https://www.aliexpress.com/item/Qi-Wireless-Newest-Charger-for-iPhone-Samsung-Galaxy-S3-S4-Note2-Nexus-All-free-shipping/32735986077.html -
And same seller has one it seems, at 2€78, but only interesting if you buy 1 item to get free shipping, else the one at 3€ is cheaper as there's no limit in item count for free shipping option
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@NeverDie I found a good way to open them without any damages.
I have that cheap DIP chip extractor that's very bad at doing it's job, but it happens that it's the perfect size to fit in the vents at the bottom, if you put it inward and pull you can pop up the bottom cover easily.I bought 10 white chargers from the "woweinew" shop for 30$ with China Post Registered Air Mail included after a few seconds of negociations.
I also found some SMD 7021 breakouts with only minimum components onboard, they are a bit more expensive but save some space in PCB surface and thickness. And no need to waste time removing and shorting the voltage regulator.
https://www.aliexpress.com/item/Industrial-High-Precision-Si7021-Humidity-Sensor-with-I2C-Interface-for-Arduino/32524005324.html
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Just FYI: it turns out you have to avoid exposing the si7021 sensor to high humidity (>80%) unless you turn its buiilt-in heater on--which, unfortunately, will drain a battery rather quickly. It's in the datasheet, but not as prominently as it should be. Therefore, going forward, I'm switching to the BME280, which costs more but appears not to have this issue. I do have some si7021's, but I think I'll probably only trust the temperature reading and consider the humidity reading as a rough gauge only.
