Guru
Joined: 24/12/2017
Location: AustraliaPosts: 1694
| Posted: 02:22am 18 Feb 2024 |
Others may know better but I believe the clock signal is unidirectional, transmitted by the Pico and received by the keyboard. So that should be OK, it may be marginal but if it works then good.
The data line is bidirectional so the keyboard is transmitting 5v logic signal to the Pico and the Pico is transmitting 3.3v logic to the keyboard. A 1k resistor in series with the keyboard signal should protect the Pico input. To be safer a 1k8 to 2k2 resistor from the Pico input to GND to would make a voltage divider that will reduce the 5v to something near enough to 3.3v. The data to the keyboard may be marginal but again if it works...
A level shifter is not expensive though.
The only place I know to get a kit for something like this is Silicon Chip which uses a normal Pico.
Bill