GPSCTL(1) GPSD Documentation GPSCTL(1) (NAME) gpsctl - GNSS (SYNOPSIS) gpsctl [OPTIONS] [serial-port] gpsctl -h gpsctl -V (DESCRIPTION) gpsctl GNSS NMEA (vendor-binary) . (baud rate) . : . GNSS gpsd gpsctl gpsd . gpsd gpsctl (root) . gpsd (root) . 'dialout' . sudo . (OPTIONS) : -?, -h, --help . -b, --binary GNSS ( binary). -c RATE, --rate RATE (cycle time) . . . -D LVL, --debug LVL (debug). -e, --echo . -t . : ASCII . -f, --force ( ). -l, --list . -n, --nmea GNSS NMEA. -r, --reset () GNSS. . -R, --rmshm GPSD SHM . GPSD . -s SPEED, --speed SPEED (baud rate) . -s . GPS USB Bluetooth 8N1 UART GPS . GPS ( ) NVRAM . -t TYPE, --type TYPE . -T TIMEOUT, --timeout TIMEOUT (timeout) . . -V, --version . -x STR, --ship STR GNSS. C . \xNN \e ESC . In normal mode, through _gpsd_, the decoded string is passed through, unchanged top _gpsd_ which in turns sends it to the receiver. Headers, checksums, and suffffices must be provided. In low-level, (direct) mode *gpsctl* will provide packet headers and trailers and checksum as appropriate for binary packet types, and whatever checksum and trailer is required for text packet types. You must include the leading $ for NMEA packets. When sending to a UBX, Allystar or CASIC device, the first two bytes of the string supplied will become the message class and type, and the remainder the payload. When sending to a Navcom NCT or Trimble TSIP device, the first byte is interpreted as the command ID and the rest as payload. When sending to a Zodiac device, the first two bytes are used as a message ID of type little-endian short, and the remainder as payload in byte pairs interpreted as little-endian short. For all other supported binary GPSes (notably including SiRF) the string is taken as the entire message payload and wrapped with appropriate header, trailer and checksum bytes. -t gpsctl -l . . gpsctl . ( .) Generic NMEA . GPS NMEA (probes) . ( SiRFStar I SiRF .) GPS . (-r) . gpsctl : (-b -n) (-s) (-c) (-x). (ENVIRONMENT) GPSD_SHM_KEY -R . gpsd . (EXAMPLES) gpsctl /dev/ttyUSB0 0 (USB serial device 0). . -f GPSD . gpsctl -f -n -s 9600 /dev/ttyUSB0 ( gpsd) GPS NMEA 9600bps. GPS . gpsctl -x '\xb5\x62\x0a\x04\x00\x00\x0e\x34' UBX-MON-VER GNSS gpsd. (BUGS) SiRF GPS SiRF . NMEA . . . (EXIT STATUS) 0 . 1 . (SEE ALSO) gpsd(8), gpsdctl(1), gps(1), ubxtool(1), zerk(1) (RESOURCES) : (COPYRIGHT) This file is Copyright by the GPSD project SPDX-License-Identifier: BSD-2-clause (AUTHORS) Eric S. Raymond GPSD, Version 3.27.5 2025-11-04 GPSCTL(1)