Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By Sum~guy
#82477 I'm looking for circuit ideas for building a solar-powered wifi pool thermometer around a ESP8266-01 module. Probably looking at an i2c bus temperature transducer unless there's a way to connect an analog transducer signal directly to AD input. There are a few different wireless pool thermometers out there but they all seem to be paired to dedicated receiver unit (table-top or wall-mounted) and not accessible via phone app or web browser.

So my idea is to make pool-temp information available to cell phone / web browser as well as make a dedicated remote monitor using another ESP8266-01 module driving something like an ePaper display panel (or some sort of display panel). Software is the big issue for me (I'm not big into programming these things yet) - would the Sonoff firmware be best for a project like this?
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By btidey
#82480 DS18B20 temperature sensor would be a good choice here. Accurate, 1 digital IO, library support, and waterproof versions available.

As it is a pool thermometer the temperature should be changing quite slowly so you can exploit deep sleep with a relatively slow update interval to minimise power requirements.

You could even consider just using a LIPO battery like a 18650 and avoid the hassle of solar power. You could fairly easily get over a year usage between recharge.

There are lots of examples of ESP 18B20 combinations on the web. E.g. ... 0-sensors/
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By ian
#82546 I agree with btidey.
I'll take the opportunity to plug my own board:
Sample code is provided for the 18B20 & you can try I2C (BMP180 etc) devices too.
You might be better getting something working on your bench before you look at solar power.