EHS8 and GPS Configuration (JSR179 Java Location API) | Telit Cinterion IoT Developer Community
May 18, 2019 - 7:41pm, 17439 views
Hello,
For testing the GPS Engine on the concept board using the JSR179, do we need to configure any settings via AT commands before using JSR179? If not, what sort of GPS configuration does it configure to if its not using A-GPS? Is it using Local GPS?
Also, do we need to buy an external antenna when using GPS on this concept board?
Thanks,
Jason
Hello,
The antenna configuration depends on the antenna type that you have - if it is passive or active.
For active antenna you need to chenge AT^SCFG "GPIO/mode/GPSANT" setting to "std". If it' set to "gpio" the antenna power line is used as GPIO. SGPSC: "Power/Antenna" is by default set to "auto" which is fine. "Mode/Antenna" should be changed to 1.
Please also provide that the antenna has sky visibility.
Regards,
Bartłomiej
Hi Bartek
I tried the setting you recommended and its still not working. It is an active antenna with 5m cable in length. What I am not sure about is whether if its antenna, area or GPS/Antenna connector problem. I can read GPGSV values but not GPGGA. From the GPGSA, the GPS module sees there are 8 - 12 satellites, but it cannot get a fix. What I am also not sure is if the cable is too long? Thats why I wanted some info as to what not to get as a test antenna for the board. Is there a way to test antenna and the connector to see what is working or not?
Thanks, really appreciate your assistance!
Hello,
You can find the document for GPS and some other documents here:
https://iot-developer.thalesgroup.com/documentation/download-documentati...
Please browse to 'ehsx' and then to 'ehs8...'.
If the module can find satellites, it suggests that the connection and configuration should be correct. The cable should also not be a problem.
Could you paste the NMEA output and additionally AT^SGPSC? and AT^SCFG? outputs?
Regards,
Bartłomiej
Hello,
Here is the output you require:
AT^SGPSC?
^SGPSC: "Engine","0"
^SGPSC: "Nmea/Output","on"
^SGPSC: "Nmea/Freq","1"
^SGPSC: "Nmea/Data","GGA,GSA,GSV,RMC,VTG"
^SGPSC: "Nmea/Interface","local"
^SGPSC: "Power/Antenna","auto"
^SGPSC: "Mode/Antenna","1"
^SGPSC: "Assist/Address","FQDN","supl.google.com","7276"
^SGPSC: "Assist/Data"
^SGPSC: "Assist/Connection"
OK
AT^SCFG?
^SCFG: "Audio/Loop","0"
^SCFG: "Call/ECC","0"
^SCFG: "Call/Speech/Codec","0"
^SCFG: "GPRS/AutoAttach","enabled"
^SCFG: "Gpio/mode/ASC1","std"
^SCFG: "Gpio/mode/DAI","gpio"
^SCFG: "Gpio/mode/DCD0","gpio"
^SCFG: "Gpio/mode/DSR0","gpio"
^SCFG: "Gpio/mode/DTR0","gpio"
^SCFG: "Gpio/mode/FSR","gpio"
^SCFG: "Gpio/mode/GPSANT","std"
^SCFG: "Gpio/mode/HSIC","rsv"
^SCFG: "Gpio/mode/PULSE","gpio"
^SCFG: "Gpio/mode/PWM","gpio"
^SCFG: "Gpio/mode/RING0","gpio"
^SCFG: "Gpio/mode/SPI","rsv"
^SCFG: "Gpio/mode/SYNC","gpio"
^SCFG: "Ident/Manufacturer","Cinterion"
^SCFG: "Ident/Product","EHS8"
^SCFG: "MEShutdown/Fso","0"
^SCFG: "MEShutdown/sVsup/threshold","0","0"
^SCFG: "MEopMode/CFUN","0","1"
^SCFG: "MEopMode/SoR","off"
^SCFG: "Radio/Band","511"
^SCFG: "Radio/Mtpl","0"
^SCFG: "Radio/OutputPowerReduction","4"
^SCFG: "Serial/Interface/Allocation","1","1"
^SCFG: "Serial/USB/DDD","0","0","0409","1E2D","0058","Cinterion Wireless Modules","EHx",""
^SCFG: "Tcp/IRT","3"
^SCFG: "Tcp/MR","10"
^SCFG: "Tcp/OT","6000"
^SCFG: "Tcp/WithURCs","on"
^SCFG: "Trace/Syslog/OTAP","0"
^SCFG: "URC/Ringline","local"
^SCFG: "URC/Ringline/ActiveTime","2"
^SCFG: "Userware/Autostart","1"
^SCFG: "Userware/Autostart/Delay","0"
^SCFG: "Userware/DebugInterface","0.0.0.0","0.0.0.0","0"
^SCFG: "Userware/DebugMode","on"
^SCFG: "Userware/Passwd",
^SCFG: "Userware/Stdout","null",,,,"off"
^SCFG: "Userware/Watchdog","0"
OK
GPS Output:
$GPGGA,,,,,,0,,,,M,,M,,*66
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,2,1,08,01,00,000,,02,04,032,,03,48,277,,04,00,000,*7D
$GPGSV,2,2,08,05,-46,023,,06,00,000,,07,00,000,,08,00,000,*53
$GPRMC,,V,,,,,,,,,,N*53
$GPVTG,,T,,M,,N,,K,N*2C
Hello,
You have configured an actve antenna.
I can't see SNR measurements in GPGSV sentence. I think that the receiver is not relly tracking the satellites. Please try to clean the assisted data as described in AT commands specification with the command AT^SGPSC="Assist/Data"[, <FieldVal>, <ActVal>]. Then I'd suggest to establish A-GPS connection as described before and then start GPS engine again. Pleaqse make sure that the antenna is located properly.
Regards,
Bartłomiej
Strange, I can still get GPGSV result like the one I posted even when I am not using active antenna (plugged in). I thought you said EHS8 does not have internal antenna?
Hello,
Testing with my EHS8 module I can observe the similar output when there is no antenna connected. There are GPGSV sentences with the same (not changing in time) ***** of satellites and no SNR's. When I connect the antenna this ***** is changing (especially when I delete assisted data before) and SNR's are displayed - it looks like the receiver is scanning the satellites and tries to measure the signal. When no antenna connected it probably constantly tries to measure the same satellites without success and that's why you see what you see.
Is it possible that you have a passive antenna connected while the module is configured for active antenna?
Regards,
Bartłomiej
Hi Bartek,
Its an active patch antenna. The power input is 3 - 5V, 1575.42 MHz frequency, 28 dB peak gain with amplifier. Pretty much standard when it comes to external cable patch antennas.
What I cannot determine is, whether the antenna is not working, the antenna is not compatible with the board, or the board is not supplying power to antenna (despite setting it to do so). Is there a way to test voltage or ohm resistence at the GPS connector on the board?
Thanks,
Jason
Hi,
According to EHS8 hardware description Vmax for antenna power is 5V. The input current has to be limited at 200mA (antenna short circuit protection). Antenna must have 50Ω impedance. The concept board provides GPS power circuit.
The antenna socket is soldered to the board, so it should be possible to measure the voltage on the socket legs. Please try.
Regards,
Bartłomiej
I came up with 3.27V at the connector when power to antenna is at auto. The voltage remains the same irrespective whether I start GPS engine at mode 3, or when its off (0). Is this normal?