Marathonman
Well-known member
So after doing a little research into ttl and ttl compatible devices i have come to this conclusions.
Since we all know the Teensy 4 and 4.1 are 3.3 volts and basically anything higher then 3.6 on any one pin will kill it. "BUT" if you are trying to interface the Teensy to a ttl compatible device that is powered by 5 volts that means the input is considered high above 2 volts. If this is a one way signal from the Teensy to the ttl compatible device like i am doing to a ttl compatible H bridge driver then the Teensy will work without a level translator or level shifter. Remember this is from the teensy to the ttl compatible device not from the ttl compatible device to the Teensy.
So why do I know this, because I have a Teensy 4.0 attached to 8 Nexperia 74VHCT595 8 bit shift registers (ttl compatible) powered by 5 volts that are logic high above 2 volts and work just perfect.
So the conclusion of this post is Yes i can hook up a Teensy 4 or 4.1 to any TTl compatible device if it is one way from the Teensy to the ttl device without a level translator or level shifter.
So the conclusion of this post is Yes i can hook up a Teensy 4 or 4.1 to any TTl compatible device if it is one way from the Teensy to the ttl device without a level translator or level shifter.
SO according to this web site i am right a 3.3 volt Teensy output can interface with a 5 volt ttl device input but not from a 5 volt output to the Teensy 4/4.1 input without level shifting.
https://hackaday.com/2016/12/05/taking-it-to-another-level-making-3-3v-and-5v-logic-communicate-with-level-shifters/#:~:text=If%20you%20are%20lucky%20the,without%20any%20extra%20hardware%20required.
Regards,
Marathonman