Interfacing with TTL devices

[RebelJD]

Hello, I want to connect a quadrature encoder with 5v TTL outputs to ESP32 inputs. I realize I need some type of level shifter so I’m looking for options on how to do this. I’ll breadboard it first but ultimately want to make a pcb. I also need to connect ESP outputs to a Digital Read Out (DRO) which requires 5v TTL signals. Any help would be appreciated.

[gtjoseph]

The TXS0108 series of level shifters are popular, cheap and dead simple to use.
https://www.ti.com/lit/ds/symlink/txs01 ... 5947678061

You can get just the chips themselves or get them pre-mounted to a carrier board with standard pin spacing.

[RebelJD]

thanks, I'll give it a try.

[MicroController]

For input of 5V digital signals into a 3.3V IO, a 1:2 voltage divider made from two resistors would be the most simple solution. Pro: cheap, easy, virtually unlimited bandwidth; con: lower input impedance, may be not suitable for high-impedance signal outputs.

You can find all kinds of solutions for 3.3V<->5V level shifting, from extremely cheap little boards with one transistor per signal line to more capable dedicated ICs. Another factor to consider here is the bandwidth required for the signal. Not every chip/circuit will be able to cleanly level-shift, say, a 1Mbps serial signal, while most will handle 100kHz well.