I'm a programmer, not a wizard. I've read up as much as I can, including the similar questions list from this question, but, they blew by me pretty quick. So here we go:
A project I'm doing some code for started on Arduino, at 5V. It has a flow meter (Hall effect sensor) at 5V, a pressure transducer sensor at 5V, and a I2C LCD display at 5V.
Now the board is being changed from Arduino, to a 32bit board that will run at 3V3, and has zero 5V tolerant pins.
Here are my questions:
The LCD at 5V is only getting input over I2C, but I worry that the 1s may be weak, so I'm going to add a bi-directional level-shift between the board and the display. Good idea? Unnecessary? Alternative ideas?
The flow meter (Hall effect sensor), powered by 5V, sending input back to the controller... will it exceed the max threshold for 3.3V? I would think so, as I would think the pulse back is 5V HIGH. Can I use the same bi-directional level-shift as #1, as it has 4 channels? I would think so, as it is just coming back HIGH, in pulses.
The pressure transducer sensor is analog, so obviously it is coming back at 5V. Can I use, yet again, the same bi-directional level-shift between the input and the board, or is there a better way?
I figure if I have to add a component(s), I might as well add the fewest possible, to limit the number of components that can fail. So if I can get away with a single 4 or 8 channel level shift... I'm happy.
I'd add in spec sheets for all the items, but they were just stuff bought randomly off Amazon, I'll do the best I can to give as much as I can find on them, since I don't know their internal components.
The flow meter is a -201 variant, YF-S201 is about the closest I've seen to having data on it.
The pressure transducer is linear, so, from description: 0-500 psi (Gauge Pressure) Output: 0.5-4.5V linear voltage output. 0 psi outputs 0.5V, 250 psi outputs 2.5V, and 500 psi outputs 4.5V
The LCD is a 204A variant. 20 characters, 4 rows