An accurate digital bi-directional solar meter in order to see and monitor the net effects of my solar setup. The commercial ones are very expensive. There are no cheap solutions. However, there are plenty of projects that others have done. But, they are grossly inaccurate and just toys at best.You're MacGyver now?
What are you working on?
Accurately measuring anything any more has become very difficult. China has inaccurately copied and stolen all of our measuring device designs. However, they cheapened them to the point where most are just worthless now. So, one has to either pay a lot of money or make them themselves.