Thanks for that, I wasn't aware the USB port on the D1 was for power and programming only. My fault for not researching it properly! I shall break out the GPS USB lines and assign the signals to the appropriate ports on the D1 and will power both devices conventionally. Many thanks for your kind ass...

I am using a D1 Mini [ ESP-8266-12F micro-USB port ] with a USB GPS ‘mouse’ plugged into the on-board USB port to create a small stand-alone GPS-over-Wi-Fi unit. Software is loaded to send the GPS serial data via Wi-Fi to an MQTT Broker for use with Node-Red. 5 volt power was applied to the D1 via t...