IoT Kit with power and solar charger
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IoT Kit with power and solar charger

by garnold on Sun Jul 21, 2019 8:18 pm

I'm trying and getting rather frustrated with building a weather station for my home. Just about all weather station kits I have found are units that either stay in your home or require mains power. What I'm looking for is the following....

    ESP8266 or ESP32 based board
    Proper charging board
    Lipo battery
    Solar charger to keep the system running
    A nice selection of weather sensing options
    Some kind of kit that I can 3d print and put it all together

Here are some of the challenges that I'm running into....

    Boards are drawing to much power and require modifications that are above my skill level to reduce the power draw
    Chargers are not allowing the ability to draw power and charge at the same time so I just don't know what to buy
    Good sensors to use for something like this. Though the BME280 is looking like the way I might go
    What solar panel to buy that will charge the battery and not need more tools to work correctly because it over charges with to much voltage
    A case for the solar panel so I can be mounted outside and not get damaged with poor weather

You can find bits and pieces of information about this on the web, but for noobs like me it's just to hard to put this all together. I just keep buying stuff thinking I might get it right this time and failing which is really a bummer!

One of the many things I love about Adafruit is that you don't sell junk! Your kits are well designed and planned out quite nicely. I'm fully aware of the fact that this kit might cost a few bucks, but if I can feel comfortable knowing that the money is well spent on parts that will all work together then.... "TAKE MY MONEY". HAHAHA

Thank you for all the great tools and the wonderful guides that have helped me along so far ;-)

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Re: IoT Kit with power and solar charger

by adafruit_support_mike on Mon Jul 22, 2019 12:09 pm

Design is the art of making tradeoffs between conflicting requirements, and in this case you have a couple that pull strongly in opposite directions: Wifi devices like the ESP8266 use at least 80mA, and getting long battery life means using as little current as possible.

One way to find a compromise between the two is to use what’s called ‘strobed power’.. only turning the microcontroller on long enough to collect readings and transmit them, then shutting it off again. We have a TPL5110 breakout that controls power to a load, and uses less than 100nA while sleeping:


The TPL5110 wakes up at intervals from 10ms to 2 hours, and has a DONE pin so a microcontroller can tell it to shut off power and sleep until its next wake-up time.

That strategy saves lots of power at the cost of losing always-on operation.

Another option is to use a less power-hungry microcontroller to collect the data, with an ESP8266 or ESP32 coprocessor that only handles WiFi communication, and can be shut down when it isn’t transmitting an update. Our Feather M0 and ItsyBitsy M0 boards only use about 9mA, which is less of a load on the battery:


and our AirLift boards are ESP32 Wifi coprocessors:


We have a Solar LiPo Charger that can charge the cell while sending power to a load:


And it’s designed to work with 6V solar panels. The chip that handles the power sends output from the solar panel to the load first, then uses any excess power to charge the LiPo. In high-sun conditions, the LOAD output can approach 6V, so you’d probably want to ignore that output and connect your microcontroller to the BAT output. That would be the same as connecting the LiPo directly to the microcontroller.

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Please be positive and constructive with your questions and comments.