V_BCKP NEO_RX NEO_TX P_SCL P_SDA LNA_EN GND GND 1 2 VCC_RF 3 U4 R2 D2 D2 R1 ON/OFF S2 Si1040X 6 5 4 LNA_EN IND1 27nH R13 10K R11 10K R12 100K C13 1nF VCC_RF 3V3 C8 1nF C9 C10 C11 C12 10uF 4.7uF 10nF 100nF GND 3 GND GND NEO-M8 4 A B C D A B C D...