Forgive my ignorance of Arduino 101 here. I'm sure this question will register as 'how can he not know that', but my Googling about has only made me more confused.
I've got a project with a microcontroller (technically, I'm using an ESP8266-12E at present), and I want to power it with a single 3.7v li-ion, akin to one of these:
The controller and the components (buzzer, LED) can all be driven with 3.3v, except for the ultrasonic sensor (HC-SR04) which requires a good 5v. I tried it with 3.3v and it didn't work very well.
Soooo...how do I make the sensor work with this project? In my tiny little newb brain, since the battery only provides 3.7v, I can't really make use of the 5v pin on the ESP8266 to power the sensor. Is that right?
I read articles about using transistors or relays to resolve the problem, but they don't make sense to me. They look like special sorts of switches, not things that would pull up the voltage the way I'm wanting.
Note: I don't want to add a breakbout board or anything like that if at all possible. So, no SparkFun Logic Level converter.