Using Arduino Uno as a USB-TTL serial link to Casio FX-850P ?

[Maximilian Hohmann]

(07-21-2022 03:57 PM)Dan C Wrote:  But this seems to be a little bit to fancy for my needs, i dont need to use the CPU on the Arduino, only the USB to TTL serial connection i think.

That's what they do as well: Open two serial connections, one (called "Serial") at 9600 baud from the Arduino to the computer and the other ((called "Serial1")) at 600 baud from the Arduino to the Casio.

The program consists of nothing but an endless loop containing only these two lines:
int inByte = Serial1.read();
Serial.print(inByte, BYTE);

(07-21-2022 03:57 PM)Dan C Wrote:  hmmm, but wait! They connect the Arduino I/O pins directly to the FX-850P port? Then i assume it's safe to use the 5V levels on the Arduino to the FX-850P?

It seems so. No resistors, nothing. Just cables.

Regards
Max