HP41C with Rp Pico attached

[blackjetrock]

(12-02-2023 10:25 AM)Tinue Wrote:  Thank you for the video, I found it very interesting. How do you interface electrically with the HP 41? I assume it is a 5V device, while the RP2040 uses 3.3V.

The RP2040 is actually sort of 5V tolerant, so it can interface to 5V systems, but only on its inputs.
the HP41C is actually a 6V-ish system, so level shifters are needed. CD40109 shifters are good to use in this situation as they drive at 6V.

Andrew