TLDR: I'm connecting a sparkfun ESP8266 thing dev board (schematics, graphical dataset) to a TFMini, and powering them both with a 9V battery involves a bit of voltage leveling so I would greatly appreciate a quick review of my plan in order to save me some pain.
I am building a module that reads the distance of what's in front of it and relay it over wifi. To achieve this, the ESP8266 sounds like the perfect component for the wifi part, and the TFMini sounds like a good cheap fit for the vision part.
Note: I am a c++ dev by trade, but this is my first time with electronic components.
This is what I have so far.
Any comment is welcome, and here are my questions:
Is a voltage regulator the proper component to deliver 5V from a 9V battery?
the BSS138 Logic Level Controller is meant to level the board's 5V Tx/Rx to the TFMini's 3.3V Tx/Rx. Can I reuse the same voltage regulator each time I need 5V, or should I connect the battery to 3 regulators: one for the board, one for the LLC, and one for the TFMini? Or should I use a separate battery each time?
Is one ground better than another? Should I plug all GND to the same one, in which case is there a better one? Can I generally do better than what's on my schematics?
anything else is wrong with this picture?