Can someone answer a simple question for me? I have ordered the ID-20 from Sparkfun. I’m designing a PCB for it (ID-20 + PIC) and want to know for sure that the TTL level output from the ID-20 needs to be inverted before it is sent to the PIC’s RX Pin. It just seems odd that it would be designed that way. Can someone confirm this?
The ID-20 can produce both inverted and non-inverted output.
Assuming you connect the format selector pin 7 to GND to select ASCII output, pin 8 produces non-inverted (normal) TTL-level output, and pin 9 produces inverted TTL-level output. So you’d want to use pin 8 as your output and connect that directly to the PIC’s UART.