JP1 Remotes

I bought a new interface and it has several RX, TX, as well as VCC (which I know is not needed for the this application) voltage options it came configured for 3.3V but it also has 5V 2.5V 1.8V TTL level options, so which is the right one?

PS: I bought this version as I also dabble in router firmware replacement so this would also help with firmware recovery should I flash the wrong or a damaged file

Thanks

I only see 1 of each on the 6 output pins, so I would assume you would use those.

3.3V is safest. Most remotes use two 1.5V (nominal) battteries in series, so they provide close to 3.2V when new.