UART Connection
	Patch Antenna
	SAW Filter and LNA
		pins:
			1 VCC
				voltage: 3.2..5 V, with ripple 50 mVpp (typical 3.3 V) = 0.165 V
				power consumption: @ 3.3 V: 53 mA max.
			2 ENABLE (floating is OK)
				1.8 V <= V_ENABLE <= VCC	enabled
				0 V <= V_ENABLE <= 0.25 V	disabled, power consumption: 15 uA
			3 GND
			4 VBACKUP
				2.0..4.3 V (REQUIRED)
				OK is 3.7 V Li Ion (with capacitor filter)
				power consumption: 10 uA
			5 3D-FIX (output)
				(floating OK)
			6 DPLUS USB
				5 V
			7 DMINUS USB
				5 V
			8 GND
			9 TXD (output) [NMEA]
				high: 2.1..2.8 V
				low: 0..0.8 V
			10 RXD (input) [for firmware update]
				high: 2.1..2.8 V
				low: 0..0.9 V
Reset device before talking to it
gpsd-clients
	see /etc/default/gpsd for server config