I want to build some small wireless temperature measurement boards, to sprinkle around the house. I'd like to power these from a single coin cell battery (CR2032).
For these I'd like to use the DS18B20 sensor. These sensor require a minimal voltage of 3v. A coin cell will however only provide 3v when it's full, and will drop to around 2.6v when 90% discharged.
(The ATMega328p and NRF24L01, I plan to use, will work just fine at voltages down to 2v, so only the DS18B20 requires 3.3v.)
So I've come up with the following solutions:
- Use two coin cells, and a (low quiescent current) voltage regulator. (Disadvantage: takes more space, more batteries, slightly more expensive.)
- Use a boost regulator. (Disadvantage: even more expensive, and a lot more complex (for me at least).)
- Implement a voltage doubler to power the DS18B20 when needed (every 15 minutes). To regulate the voltage I'd add a 3.3v zener diode to the output. (dirt cheap to implement)
I tend to lean toward option 3, but my question is, could it even work?
Is there something to look out for?
Or is there an even better solution?
edit I was planning to use the Dickson doubler circuit.