I am having an issue adding a 5v step-up module to power some WeMos D1 mini. It will be used with solar panel battery charger.
It is constant ~5v (5v - 5.6v) until I connect it to the WeMos 5v pin. Then it drops to ~1.5v (1.1v - 1.3v). When I disconnect it from WeMos 5v, it backs to 5v. (see attached images)
At this point, there is no sketch running on WeMos. I already tried to replace the step-up module, even with other manufacture.
I am lost...