| 180 | | [=#evam8m] |
| 181 | | === '''u-blox EVA-M8M-0''' (GW553x) === |
| 182 | | References: |
| 183 | | - [https://www.u-blox.com/sites/default/files/products/documents/EVA-M8M-FW3_DataSheet_%28UBX-16007405%29.pdf EVA-M8M Datasheet] |
| 184 | | - u-blox M8 Receiver Protocol Specification (UBX-13003221) |
| 185 | | |
| 186 | | Features: |
| 187 | | * 72-channel u-blox M8 concurrent position receiver engine supporting multiple concurrent Global Navigation Satellite System's (GNSS): |
| 188 | | - [#gps GPS]: L1C/A (1575.42MHz) |
| 189 | | - [#glonass GLONASS]: L1OF (1602MHz) |
| 190 | | - [#qzss QZSS]: L1C/A (1575.42MHz) |
| 191 | | - [#sbas SBAS]: WAAS/EGNOS/MSAS: L1C/A (1575.42MHz) |
| 192 | | * [#dgps Differential GPS] (DGPS): [#rtcm RTCM] 10402.3: |
| 193 | | * Navigation Update Rate: 10Hz (GPS&GLONASS) or 18Hz (GPS) |
| 194 | | * Accuracy: |
| 195 | | - Velocity: 0.05m/s |
| 196 | | - Heading: 0.3degrees |
| 197 | | - Horiz position: Autonomous 2.5m / SBAS 2.0m |
| 198 | | - PPS: 30ns RMS, 99% 60ns |
| 199 | | * Sensitivity: |
| 200 | | - Tracking & Navigation: -164dBm (GPS&GLONASS) -163dBm (GPS) |
| 201 | | - Re-acquisition: -159dBm |
| 202 | | - Cold start: -147dBm |
| 203 | | * Acquisition: |
| 204 | | - Cold start Time-to-First-Fix (TTFF): 27s (GPS&GLONASS) or 30s (GPS only) |
| 205 | | - Hot start Time-to-First-Fix (TTFF): 1s |
| 206 | | * [#pps PPS]: |
| 207 | | - 30ns accuracy, configurable via UBX-CFG-TP5 with rate 0.25Hz to 10Mhz, high or low polarity, 0 to 2^32^ ms pulse width (see u-blox M8 Receiver Description UBX-13003221 Chapter 18) |
| 208 | | - Note that for best PPS accuracy it is recommended to disable the SBAS subsystem |
| 209 | | * Communication: |
| 210 | | - 9600 baud, 8bit no parity, 1 stop bit, no flow control supporting multiple protocols: |
| 211 | | - [#nmea0183 NMEA]: Input / Output ASCII 0183 version 4.0 (configurable for 2.3 or 4.1) |
| 212 | | - [#ubx UBX]: Input / Output binary u-blox proprietary |
| 213 | | - [#rtcm RTCM]: Input, messages 1,2,3,9 |
| 214 | | * Active Antenna: 15dB to 50dB recommended |
| 215 | | * Power Consumption (not including active antenna power consumption): |
| 216 | | - ~27mA (90mW) during acquisition for GPS & GLONASS, 22mA for GPS/QZSS/SBAS |
| 217 | | - ~25mA (83mW) during continuous mode tracking for GPS & GLONASS, 19mA for GPS/QZSS/SBAS |
| 218 | | - ~5.5mA (18mW) during 1Hz power-save mode tracking (for GPS/QZSS/SBAS only) |
| 219 | | |
| 220 | | Power-on Defaults: |
| 221 | | * 9600 baud, 8 data bits, no parity, 1 stop bit: |
| 222 | | * GPS & GLONASS enabled |
| 223 | | * SBAS enabled |
| 224 | | * output: NMEA: GGA, GLL, GSA, GSV, RMC, VTG, TXT messages |
| 225 | | * input: UBX, NMEA, RTCM |
| 226 | | * PPS: 100ms active high pulse at 1Hz |
| 227 | | |
| 228 | | Note that the EVA-M8M is not connected to an RTC, battery backup, or external flash on Gateworks designs (which disallows for permanent configuration storage and firmware upgrade) |
| | 180 | |
| 245 | | |
| 246 | | [=#w2sg0008i] |
| 247 | | === '''Wi2Wi W2SG0008i''' (GW54xx rev C-F, GW53xx rev A-F, GW52xx rev A-D, GW51xx) === |
| 248 | | References: |
| 249 | | * [http://dev.gateworks.com/datasheets/W2SG0008i.pdf Product Brief] |
| 250 | | * [http://dev.gateworks.com/datasheets/W2SG0008i_Datasheet_Rev1.48.pdf Product Datasheet] |
| 251 | | * NMEA Reference Manual (CS-129435-MA-1) |
| 252 | | * One Socket Protocol Interface Control Document (OSP_ICD) (CS-129291-DC-15) |
| 253 | | |
| 254 | | Features: |
| 255 | | * CSR/SiRF SiRFStarIV GSD4e |
| 256 | | * 48 channel continuous tracking receiver (reports best 12 of 48): |
| 257 | | - [#gps GPS]: L1C/A (1575.42MHz) |
| 258 | | - [#sbas SBAS]: WAAS/EGNOS/MSAS/GAGAN: L1C/A (1575.42MHz) |
| 259 | | * [#dgps Differential GPS] (DGPS) |
| 260 | | * Navigation Update Rate 1-5Hz |
| 261 | | * Acquisition: |
| 262 | | * Hot Start TTFF@-136dBm: 0.6sec |
| 263 | | * Min Acquisition Signal: -153dBm |
| 264 | | * Sensitivity: Tracking -163dBm / Acquisition -148dBm |
| 265 | | * Accuracy: |
| 266 | | * 3m stationary horizontal (with DGPS), 15m stationary horizontal (without DPGS) |
| 267 | | * Communication: |
| 268 | | * 8 data bits, no parity, 1 stop bit (aka '''8N1''' or '''cs8'''), no flow control |
| 269 | | * baudrate: can vary between 4800 and 115200 (see below) |
| 270 | | * [#nmea0183 NMEA 0183] v3.01, configurable 1 to 255 seconds between messages, supports: GGA, GLL, GSA, GSV, RMC, VTG, ZDA messages |
| 271 | | * [#osp OSP™] (SiRF BINARY™) proprietary protocol |
| 272 | | * [#pps PPS]: |
| 273 | | * ±1us accuracy, rising edge 1Hz 200ms width active-high when there are 5+ satellites used in a fix (not configurable) |
| 274 | | * Internal LNA Gain: |
| 275 | | * High Gain Mode '''(default)''' intended for use with passive antennas |
| 276 | | * Low Gain Mode intended for use with active antennas (that have their own LNA) |
| 277 | | |
| 278 | | Power-on Default configuration: |
| 279 | | * 4800 baud |
| 280 | | * NMEA 0183 output 1Hz |
| 281 | | * LNA high gain mode |
| 282 | | |
| 283 | | |
| 284 | | ==== W2SG0008i (SiRFStarIV) NMEA Command Reference: ==== |
| 285 | | References: |
| 286 | | * NMEA Reference Manual (CS-129435-MA-1) |
| 287 | | |
| 288 | | Notes: |
| 289 | | * NMEA 4800bd 8N1 (8 data bits, no parity, 1 stop bit) is the default power-on communication mode of the W2SG0008i |
| 290 | | * Flow control is not used between the GPS and the host processor and thus should be disabled |
| 291 | | * SiRF NMEA reports a maximum of 12 satellites in its GSV messages even though more may be visible (use [#osp OSP] protocol if you want more detail on the 48 channels) |
| 292 | | |
| 293 | | |
| 294 | | Examples: |
| 295 | | * The proprietary PSRF100 command will change the baudrate and data format. Consult the reference manual (above) section 2-3 for more info. |
| 296 | | * Example: '''To change the baud from the power-on default 4800bd to 9600bd''': |
| 297 | | {{{#!bash |
| 298 | | # set tty for current baudrate and data format |
| 299 | | stty -F /dev/gpsdevice 4800 cs8 |
| 300 | | # send a PSRF100 command to set the format (1=NMEA mode) baudrate (9600) and data format |
| 301 | | echo "\$PSRF100,1,9600,8,1,0*0D" > /dev/gpsdevice |
| 302 | | # set new tty baudrate for further communication |
| 303 | | stty -F /dev/gpsdevice 9600 |
| 304 | | }}} |
| 305 | | * 1,9600,8,1 is the data payload. Specifically, the first '1' specifies that this is a NMEA message, while the rest of the payload determines the speed of the GPS receiver. |
| 306 | | * ensure that /dev/gpsdevice corresponds to the correct tty above in the [#hardware hardware mappings section] |
| 307 | | * if changing the above NMEA sentence, be sure to [http://www.hhhh.org/wiml/proj/nmeaxor.html update the checksum] |
| 308 | | * The proprietary PSRF103 command will set the rates of the various NMEA messages. Consult the reference manual (above) section 2-6 for more info. |
| 309 | | * Example: '''To set the period of all messages to one every 1 seconds''': |
| 310 | | {{{#!bash |
| 311 | | # set tty for current baudrate and data format assuming power-on default of 4800bd 8N1 |
| 312 | | stty -F /dev/ttymxc4 4800 cs8 |
| 313 | | echo "\$PSRF103,00,00,01,01*26" > /dev/gpsdevice # GGA every 2 sec |
| 314 | | echo "\$PSRF103,01,00,01,01*25" > /dev/gpsdevice # GLL every 2 sec |
| 315 | | echo "\$PSRF103,02,00,01,01*28" > /dev/gpsdevice # GSA every 2 sec |
| 316 | | echo "\$PSRF103,03,00,01,01*27" > /dev/gpsdevice # GSV every 2 sec |
| 317 | | echo "\$PSRF103,04,00,01,01*22" > /dev/gpsdevice # RMC every 2 sec |
| 318 | | echo "\$PSRF103,05,00,01,01*21" > /dev/gpsdevice # VTG every 2 sec |
| 319 | | }}} |
| 320 | | * if changing the above NMEA sentences, be sure to [http://www.hhhh.org/wiml/proj/nmeaxor.html update the checksum] |
| 321 | | * ensure that /dev/gpsdevice cooresponds to the correct tty above in the [#hardware hardware mappings section] |
| 396 | | [=#w2sg0008i-lna] |
| 397 | | ==== W2SG0008i LNA Gain ==== |
| 398 | | The W2SG0008i used on most Gateworks Ventana boards defaults on power-up to use its internal high gain LNA which is appropriate for passive antennas but not necessarily appropriate for active-antennas which have their own LNA at the antenna. |
| 399 | | |
| 400 | | While Gateworks has tested,,1,, and found no adverse affects in terms of GPS sensitivity and accuracy when using the [http://shop.gateworks.com/index.php?route=product/product&path=70_71&product_id=51 GW10044 Active GPS antenna] with the default power-up high-gain internal LNA your results may vary depending on your antenna and system characteristics. |
| 401 | | |
| 402 | | If you wish to configure the Ws2G0008i internal LNA for low-gain you must do the following according to the [http://dev.gateworks.com/datasheets/W2SG0008i_Datasheet_Rev1.48.pdf W2SG0008i datasheet] section 6.4.1: |
| 403 | | 1. Switch GPS Communication Protocol from NMEA to OSP mode. |
| 404 | | 2. Send Tracker Configuration Message (OSP MID 178, 02) - (Disable Internal LNA and drive GPS_EXT-LNA_EN signal) |
| 405 | | 3. Wait for SiRFStarIV ACK |
| 406 | | 4. Perform a Hot Start reset; Tracker Configuration setting requests in message (OSP MID 178, 02) will apply after performing this reset. |
| 407 | | 5. Wait for SiRFStarIV ACK |
| 408 | | 6. Switch GPS Communication Protocol back to NMEA. |
| 409 | | |
| 410 | | The gateworks-gps-utils.tar.gz attached at the bottom of this page contains source for a C application "sirf_osp" that will do the above in a short series of commands. After building the application for your BSP run the following commands to put the gps module into LNA low gain mode: |
| 411 | | {{{#!bash |
| 412 | | DEVICE="/dev/ttymxc4" # Refer to Hardware UART Mappings section above to verify device |
| 413 | | ./sirf_osp $DEVICE 4800 osp 115200 # Changes board from default NMEA/4800 to OSP/115200 |
| 414 | | ./sirf_osp $DEVICE 115200 lna low # Sends OSP command for LNA low mode |
| 415 | | ./sirf_osp $DEVICE 115200 config # Prints configuration to verify LNA mode of low ("LNA:1") |
| 416 | | }}} |
| 417 | | ,,1 See Indoor GPS Testing section below for test details and complete sirf_osp usage example |
| 418 | | |
