Ttlx/Dix: Ttl Input/Output Or Generic Digital Inputs - Sferalabs Iono Pi IPBB20R User Manual

WARNING
Never apply voltages outside the 0-5V range to this pin to avoid damage to the Iono Pi
board and Raspberry Pi.

TTLx/DIx: TTL input/output or generic digital inputs

TTL2/DI1, TTL3/DI2 and TTL4/DI3 are dual-purpose pins. Using internal jumpers, they
serve as TTL I/O lines or generic digital inputs.
When TTL2/DI1 is configured as TTL I/O, it can be used as the DATA1 line of a Wiegand
interface, in combination with TTL1, or any other generic TTL I/O function.
TTL3/DI2, configured as TTL I/O, can be used as the DATA0 line of a second Wiegand
interface, or any other generic TTL I/O function.
TTL LEVEL CONVERTER CIRCUIT AND INPUT MODE SELECTION JUMPERS
TTL4/DI3, configured as TTL I/O, can be used as the DATA1 line of the second Wiegand
interface, in combination with TTL3, or any other generic TTL I/O function.
The TTL2-TTL4 front-end circuits have 10.0kOhm pull-up and 470Ohm series resistors.
18 Iono Pi User Guide