on a WEMOS D1 R2 I have a fingerprint scanner on SoftwareSerial mySerial(D3,D4). Also, I have a switch on D1 which is of course GPIO5 on the esp8266. The switch, or button, detects if a door is open or closed.
The problem is that the fingerprint scanner (Adafruit_fingerprint.h) will not initialize when the circuit on D1 is closed. If I open the switch during the initialization and afterwards close it, everything works fine.
Should I expect this behaviour?