I'm pretty new to custom PCB's, but learning.
I have already made a control unit off a Nano that controls a 12v solenoid with a TIP120 (flyback diode included) as well as some ancillary components like a float switch, a push button rotary encoder and an 2004 LCD that is working well.
I'm now trying to prototype using a Nano IoT 33 instead, so I can get it connected up to a MQQT platform (Cayenne) and need some help managing different power supplies. (3.3v / 5v / 12v)
I haven't mapped out the schematics yet in Fritzing yet, as I want to make sure I'm going down the right path first.
I have read that the 5V on the Nano IoT33 isn't the best, so a separate voltage converter is better to get 5v. I was planning to have a AMS1117 (capacitors includes as per the data sheet) for steady 5v supply.
The specs on the devices I am working with are the following
LCD 2004 - 5v for LCD - A4/A5 for SDA/SLA
Float switch - Effectively a push button
Flow meter is 5v -24v NPN output
Rotary encoder - says 5v on package, but I've heard people say they work fine on 3v3. If anyone can confirm that would be great.
My plan was to have 12v input supplying the solenoid, VIN on the IoT33 as well as supply power to the AMS1117.
Then the 5v power supply can supply voltage to the LCD, flow meter which I can use voltage dividers on the output to drop it to 3.3v.
The float switch and the rotary encoder can run off the 3.3v. If the rotary encoder doesn't like 3.3v then I can use it on the 5v supply and voltage dividers to drop down to 3.3v on pins, but that's easy to test on a breadboard.
Like I said I'm pretty new to all this so just wanted to check if I'm going down the right path or am I over complicating it out of my own naivety.