# GPS will not communicate CubeOrange **URL:** \ **Category:** PX4 Autopilot\ **Created:** [February 27, 2021, 9:38pm UTC](https://discuss.px4.io/t/gps-will-not-communicate-cubeorange/21202 "2021-02-27T21:38:19Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Bash](https://discuss.px4.io/user_avatar/discuss.px4.io/bash/32/8113_2.png) [@Bash](https://discuss.px4.io/u/Bash)\ **Post date:** [February 27, 2021, 9:38pm UTC](https://discuss.px4.io/t/gps-will-not-communicate-cubeorange/21202/1 "2021-02-27T21:38:20Z")
Hi all, I’ve got a cube orange that I’ve setup and got communicating with QGroundControl. I wired a MTK GPS to the proper serial RX and TX (verified with Oscope). The GPS unit has an Led on it that blinks when it gets lock, but despite this blinking I never get GPS lock in QGroundControl. I’ve enable MTK in the parameters and recycled power, still not working. I enable GPS logging and recycles power, still no logs. I connected the GPS directly to a serial terminal on the computer and I’ve verified it indeed is working. I looked at the code in src/drivers/GPS/devices/scr/mtk.cpp and mtk.h and the code commands and parsing matches the GPS device data sheets… I’m at a complete loss. I’m using Visual Studio on a Linux Debian computer. My GPS unit is a GlobalTop Titan X1 Chip. ---
**Author:** ![Bash](https://discuss.px4.io/user_avatar/discuss.px4.io/bash/32/8113_2.png) [@Bash](https://discuss.px4.io/u/Bash)\ **Post date:** [February 27, 2021, 10:16pm UTC](https://discuss.px4.io/t/gps-will-not-communicate-cubeorange/21202/2 "2021-02-27T22:16:08Z")
Update: Using the console in QGroundControl to check on the GPS I get: ```auto nsh> gps status INFO [gps] Main GPS INFO [gps] protocol: MTK INFO [gps] status: NOT OK, port: /dev/ttyS2, baudrate: 9600 INFO [gps] sat info: disabled INFO [gps] rate reading: 0 B/s nsh> ``` Isn’t GPS1 supposed to be ttyS0??? ---
**Author:** ![Bash](https://discuss.px4.io/user_avatar/discuss.px4.io/bash/32/8113_2.png) [@Bash](https://discuss.px4.io/u/Bash)\ **Post date:** [March 5, 2021, 9:45pm UTC](https://discuss.px4.io/t/gps-will-not-communicate-cubeorange/21202/3 "2021-03-05T21:45:53Z")
So I’m just going to post what I’m learning since no one seems to answer anyone’s questions on this forum…and PX4 people wonder why ArduPilot is more popular… Answering my last question “Isn’t GPS1 supposed to be on ttyS0?” NO The best way to figure out how Nuttx knows which port is which is to read the default.cmake file in the directory for you board in my case PX4-Autopilot/boards/cubepilot/cubeorange. For the Orange Cube ttyS0 is TEL1. GPS1 is ttyS2 so from gps status in the console reporting back port ttyS2 is good. Why I’m not getting any data is still an unknow. The GPS unit works, it’s at the correct baud and the protocol is MTK. My next step is to drop PX4\_INFO()s in the MTK and GPS files to track down where the data is being blocked… Stay tuned for more… ---
**Author:** ![Bash](https://discuss.px4.io/user_avatar/discuss.px4.io/bash/32/8113_2.png) [@Bash](https://discuss.px4.io/u/Bash)\ **Post date:** [March 13, 2021, 9:44pm UTC](https://discuss.px4.io/t/gps-will-not-communicate-cubeorange/21202/4 "2021-03-13T21:44:36Z")
Update: I’ve dug into the code and even though I’m still not getting lock I am getting data. In order to tell that I’m getting data I had to do the following, in MAVLink Console: gps stop gps start -d /dev/ttyS2 then gps status If I didn’t specify ttyS2 then the instantiate function would default to ttyS3 which for an OrangeCube is PX4IO and would hang the system. I did go into that function and change the default to: const char \*device\_name = “/dev/ttyS2”; So now I can simply call gps start and then gps status to get the following: ```auto nsh> gps status INFO [gps] Main GPS INFO [gps] protocol: ASHTECH INFO [gps] status: NOT OK, port: /dev/ttyS2, baudrate: 0 INFO [gps] sat info: disabled INFO [gps] rate reading: 0 B/s INFO [gps] rate position: 0.00 Hz INFO [gps] rate velocity: 0.00 Hz INFO [gps] rate publication: 0.00 Hz INFO [gps] rate RTCM injection: 0.00 Hz sensor_gps_s timestamp: 254874983 (1.185214 seconds ago) time_utc_usec: 0 lat: 415273036 lon: -713763710 alt: 15956 alt_ellipsoid: 0 s_variance_m_s: 0.0000 c_variance_rad: 0.1000 eph: 0.0000 epv: 0.0000 hdop: 0.0000 vdop: 0.0000 noise_per_ms: 0 jamming_indicator: 0 vel_m_s: 0.0000 vel_n_m_s: 0.0000 vel_e_m_s: 0.0000 vel_d_m_s: 0.0000 cog_rad: 0.0000 timestamp_time_relative: -254874983 heading: nan heading_offset: 0.0000 fix_type: 3 jamming_state: 0 vel_ned_valid: True satellites_used: 0 ``` What you’ll notice is that the status is still showing NOT OK, but I am getting the correct Lat/Lon. Next step is to but some PX4\_INFO into the MTK read functions to see why it’s showing rate read zero. ---
**Author:** ![Bash](https://discuss.px4.io/user_avatar/discuss.px4.io/bash/32/8113_2.png) [@Bash](https://discuss.px4.io/u/Bash)\ **Post date:** [March 23, 2021, 5:51pm UTC](https://discuss.px4.io/t/gps-will-not-communicate-cubeorange/21202/5 "2021-03-23T17:51:53Z")
So it seems that the PX4 code is NOT set up correctly based on brand. The only brand that will actually parse NEMA messages is Ashtech. In the ashtech.cpp the code actually parses the GGA and GSV messages outputted by a GPS unit. NONE of the other gps files decode NEMA messages… Why? (Looking at you Thomas Gubler and Julian Oes) So to actually get my GPS unit to be read you have have to tell it it’s a Ashtech gps…which it’s not. The problem with that is not you can’t update the GPS to output different messages or rates or baud because it doesn’t doesn’t use the MTK message structure… How has this code stayed like this for this long? Does everyone just use the generic GPS units that PX4 recommends? ---
**Author:** ![Chris\_Anderson](https://discuss.px4.io/user_avatar/discuss.px4.io/chris_anderson/32/3474_2.png) [@Chris\_Anderson](https://discuss.px4.io/u/Chris_Anderson)\ **Post date:** [March 23, 2021, 10:03pm UTC](https://discuss.px4.io/t/gps-will-not-communicate-cubeorange/21202/6 "2021-03-23T22:03:08Z")
You might have better luck on the PX4 Slack. I don’t think devs are on this forum as much as they are there. ---
**Author:** ![sibujacob](https://discuss.px4.io/user_avatar/discuss.px4.io/sibujacob/32/9673_2.png) [@sibujacob](https://discuss.px4.io/u/sibujacob)\ **Post date:** [November 20, 2022, 6:53am UTC](https://discuss.px4.io/t/gps-will-not-communicate-cubeorange/21202/7 "2022-11-20T06:53:40Z")
i just noticed that there is no **6th option ( NMEA generic)** on the **GPS2\_PROTOCOL**. When I enter 6th option —\> GPS2\_Protocol , the cmd **GPS STATUS** simply shows FEMTOMES protocol… Any ideas where is the generic NMEA is ? Herelink Radio Telemtery ( Android version) QGC platform Px4 stack v1.12.3 with NuttX, v8.2.0 Os Flight controller- CUBE Orange Pixhawk