Hello, I think I am finally in my final stages of a project. I am running a 3.3v pro mini off a lipo, the lipo is also powering a variable boost circuit. The circuit has a positive and negative in and out. The a6 ai thinker needs 5v (at least the board i have needs 5v). I have read the a6 ai thinker ground should be connected to the arduino. In a case like this, is ground common across the circuit? Can I connect the a6 ai thinker to the arduino / lipo ground and is that the same as connecting it to the boost circuit ground? I don't know if the boost circuit is isolating the grounds. Does it matter? should i run the arduino on 5v? I was going to use 3.3v to save power. The circuit will only be on once per day and only long enough to take two readings and establish a connection and send a text. This is done by a trigger with a rtc.
according to my volt meter, the grounds are not isolated. I would still appreciate your thoughts.
Thank you,
Anthony
Depends what the "variable boost circuit" comprises
If something you'd be knocked up yourself, then anyone's guess.
If an off the shelf item, then common usually connected.
A bit of caution, I am assuming the variable boost circuit is a boost converter available for a few $$$. All grounds must be connected however some of the boost circuits use the + as a common. Measure it to be safe and possibly save some of your parts from the fry pan. If the battery ground does not connect to anything but the boost circuit this will not be a problem but at this point I do not know. Use whatever voltage is the easiest for you. I would guess 5 would be the easiest. Use a single point ground scheme, bring all the grounds to a single point and connect them. I typically use a small piece of copper clad, cut a groove in it and it is my common point for Ground, +5 and others if needed.
Good Luck & Have Fun!
Gil