When my first child was little and it was just her and me at home she loved to watch Barney. One day, I decided to set up her potty chair in the living room and let her sit on it while she watched cartoons. I listened carefully and when I heard her pee, I got all excited and asked her if she peed in the potty. She realized she did and I told her what a good girl she was and gave her a glass of her favorite juice.
After about the first 3 times of doing it by accident and me making a big happy moment from it, she started doing it on purpose and telling me when she did it.
I know it's non-conventional but it worked.