Update README.md

Author: srg74

README.md

@@ -18,7 +18,6 @@ PCB test v0.8
 -   Waterproof enclosure IP67;
 -   Level shifter for relaible signal;
 -   Power selector (e.g 5VDC or 12VDC);
--   Signal mode select (e.g. GPIO);
 -   Serial interface connector 3.3V logic levels;
 -   IR receiver (optional);
 -   SSD1306 I2C OLED display 128x32 or 128x64 (optional);