Problem with DS18B20 (1-Wire) on WeMos D1 Mini

[makiyang614]

For the life of me I can't seem to get any kind of response out of this DS18B20 1-Wire temperature sensor on my D1 mini V2!

I've also just attempted a 1-Wire bus search using the example code in the OneWire library and it finds nothing.

I know the sensor works because it works just fine on my Raspberry Pi which I just tested.

This sensor is the version on a tiny PCB with what appears to be a 1k ohm pullup resistor.

Any ideas? Here is the DS18B20 date sheet