#Shortly after Danh corrected me and said
umbral jetty
oh interesting about the NeoPixel...Any recommendations for a better option for a lower power board then? I had this whole thing running on arduino nano but dealt with consistent issues with sdcard module breaking.
mint beacon
I think the lowest power board for circuit python that also has a great amount of CPU & RAM is either the ESP32-S2 or ESP32-S3 feathers.
I can't remember exactly which one has the lower power draw.
umbral jetty
I'll check them. I need this sensor to live as long as possible on battery (like 3 months+) so I need draw down to like 10-12maA. Thanks again for the input. Really appreciated
mint beacon
ESP32-S3 Feather: Low Power friendly! In deep sleep mode we can get down to ~100uA of current draw from the Lipoly connection. Quiescent current is from the power regulator, ESP32-S3 chip, and Lipoly monitor. Turn off the NeoPixel and external I2C power for the lowest quiescent current draw.
umbral jetty
perfect. I really under estimated the draw of the LEDs. hah
mint beacon
With the ESP32-S3 feather you can turn the LED's and other peripherals completely off.
umbral jetty
I think that will be ideal.
mint beacon
You can wake it with pinalarm have it connect to wifi, update some kind of status, then go back to sleep. It's one of the most prefered boards currently for solar/battery or other extremely low power sleep projects.
umbral jetty
yeah thats probably my plan. Its a water level sensor for a cave so every 15 min or maybe 30 minutes it will check to see if water is up to a certain point, log it to txt file on microsd and go back to sleep
Ive got a 30mAh voltaic battery with always on and may end up going a solar panel to keep it charged if needed.
mint beacon
neat project. you'll want a good waterproof enclosure for a moisture rich environment.
umbral jetty
typo... 20,000 mAh battery
yeah I have a outdoor box set up for it with cable glands for the inputs. Its gonna be pretty cool
mint beacon
also a word of caution about using amazon or other distributor batteries. they often have opposite polarity vs any of the batteries adafruit sells in their store. wrong battery polarity will instantly fry any microcontroller.
umbral jetty
ah... have you heard of voltaic? I was thinking they were reputable?
mint beacon
test the battery polarity and ensure it matches up with the + and - silkscreen next to the esp32-s3 battery input terminal.
umbral jetty
phase 2 was possibly to add GSM card. There is data coverage at this location and have it send HTTP posts to a back end service so we can follow the tracking "live"ish... thats definetly phase 2... haha
mint beacon
the feather will not accept a battery charge more than about 4.2v or it'll fry the onboard regulator. a 3.7v-4.2V nominal charge battery is required.
any normal 3.7V lipo will work. they're usually advertised as 3.7v and will charge up to 4.2v.
the only way to power the feather with 5V is via a USB plug.
umbral jetty
the voltaic system I checked out has a charge controller built into the battery and I was looking at a 5 Watt 5 Volt 35Wh system which I think should be enough even IF i dont get the power consumption down as much as I want
thats what Ive been doing is USB going through the 5v.. I think most have the built in 500mA fuse there too which makes me feel a lttle better
mint beacon
though it might be possible to power the VBUS pin with 5V. dont' quote me on that. i've never been brave enough to try it.
they'll go up to about 700ma peak but you don't want to run it much more than 400-500ma
and for a simple water sensor doubt it'll be pulling that much power anyway unless you intend on adding other peripherals.
umbral jetty
yeah an RTC but it has its own battery
mint beacon
regardless if it's a resistive type or a float. you're only measuring voltage/current not using it.
umbral jetty
its a float
mint beacon
i can recommend a really good rtc. one i've been very impressed with its time keeping.
umbral jetty
Im using the ds3231
mint beacon
has a stemma plug so will plug right into the feather no custom wiring needed.
ah perfect.
umbral jetty
ohhh interesting. I need to check out the adafruit store more. Ive been just getting stuff on amazon and hoping
mint beacon
don't forget that stemma cables are separate purchases. i usually add a few to cart with every purchase just in case.
umbral jetty
will do. I may even test out my arduino nano with circuit python and see if its much different power wise. I was running their C++ like code and it was more power efficient but it got to where like 3 times out of 10 the sd card wouldnt initialize correctly and it wouldnt write anything