Serial gateway running on coin cells. Needs to sleep
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@scalz said in Serial gateway running on coin cells. Needs to sleep:
capa buffering,
What is capa buffering? Google is not helping me
@Jason-Rennie said in Serial gateway running on coin cells. Needs to sleep:
@scalz said in Serial gateway running on coin cells. Needs to sleep:
capa buffering,
What is capa buffering? Google is not helping me
I think he means adding capacitor(s). Cr2032 will not be able to deliver its rated capacity if more than a few mA is drawn. See https://electronics.stackexchange.com/questions/234901/lithium-coin-cell-cr2032-battery-specifications for one data point.
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@Jason-Rennie
sure, but you didn't mention the whole thing, I also prefer subghz :)
cr2032 is limited, so without extras capacitors = possible brownouts + you won't get full lifetime because of its internal resistance (when power consumption >5ma generally) . even a short burst can reset your mcu (brownout)
like 100-300uf to handle H version of rfm modules, I usually place a few close to batt and rf module
also forget bad coincell brands, not good at all for lifetime.
for a commercial product, I wouldn't recommend to remove brownout protection, nor watchdog too, for saving power.I didn't know about listenmode. when I tried it worked, but this was experimental, never used it in prod.
-> custom fw with rtc and sync. simple :) -
@Jason-Rennie said in Serial gateway running on coin cells. Needs to sleep:
@scalz said in Serial gateway running on coin cells. Needs to sleep:
capa buffering,
What is capa buffering? Google is not helping me
I think he means adding capacitor(s). Cr2032 will not be able to deliver its rated capacity if more than a few mA is drawn. See https://electronics.stackexchange.com/questions/234901/lithium-coin-cell-cr2032-battery-specifications for one data point.
@mfalkvidd Yes, I need the right capacitors. I'm now designing boards for the watch and sender device using KiCAD based on moteino and easysensors but with a few differences.
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@Jason-Rennie
sure, but you didn't mention the whole thing, I also prefer subghz :)
cr2032 is limited, so without extras capacitors = possible brownouts + you won't get full lifetime because of its internal resistance (when power consumption >5ma generally) . even a short burst can reset your mcu (brownout)
like 100-300uf to handle H version of rfm modules, I usually place a few close to batt and rf module
also forget bad coincell brands, not good at all for lifetime.
for a commercial product, I wouldn't recommend to remove brownout protection, nor watchdog too, for saving power.I didn't know about listenmode. when I tried it worked, but this was experimental, never used it in prod.
-> custom fw with rtc and sync. simple :)@scalz said in Serial gateway running on coin cells. Needs to sleep:
also forget bad coincell brands, not good at all for lifetime.
This is my biggest concern at the moment. With the watch device I can resort to Lipo and recharge if needed, but the sender is best encased in silicone to protect it so its crucial that I get a long reliable battery life from it. My only option there is to use inductive charging. Which might be easy but I've not looked at the details.
I would also need to do shipping safety sheets if I use lipo but I think that it's probably just an expense. Not a project risk.
