Hi,I have paraglider model (Drone PIXY). We bought this model last year. The model includes gps chip and this chip transmits only GPRMC (one sentence from NMEA) I would like to use some ground control station for visualization parameters (lat, long, speed, azimuth, map, ...). I have happykillmore software but I have not informations from GPS modul. Can you help me with this software or tell me another software.thank youJake
You need to be a member of diydrones to add comments!
Ok, thanks for posting the .HKO file. Amazingly, the issue is due to a non-conforming NMEA message. Each line is supposed to end with <CR><LF> and every message in your log file ends with <CR><CR><LF>. This is incorrect, but it seems unlikely that Garmin would screw that up. So I suspect it's your UAV manufacturer that has done this. Anyhow, I can handle it now, so it's no problem.
The messages are also very erratic. They're arriving as often as twice a second and as slow as every 4 seconds. You've got a few problems here.
First, without GPGGA, my GCS will be useless. It will assume your altitude is 0m above sea level making Google Earth just bounce around like crazy.
Second, you appear to have a X-Bee 868 which has an RF max of 24K bps. So you should be using 19200 as a max. At 9600 and 5Hz, you're at 80% of bandwitdth capacity sending GPRMC and GPGGA. At 19200, you're at 40%. But here's the rub. The 868 have a limit of 10% duty cycle and this seems to have been poorly implemented by Digi and even less explained exactly how they calculate this value. That may have been the reason the developers of your UAV decided upon 38400 to try and get around this issue. Sending only GPRMC at 5Hz over a 38400 baud connection, is almost exactly 10%.
At this point, you need to decide what kind of range you need and if you want to hack the 868 for more functionality. With the amount of money you've spent on this project, what's another couple hundred dollars USD, right? Also, what kind of application are you performing? Is this a hobby project or a commercial one?
My "perfect" and cheap solution would be to buy a MTK GPS, ArduIMU V2 (this is the OLD one for the original ArduPilot) and a magnetometer. Then I would send the data from the IMU to the X-Bee using the ArduPilot legacy protocol. You'll have Pitch, Roll, Yaw, Heading, Altitude, Lat, Long, Sats, GPS Lock....pretty much everything you'd need for full functions on the GCS (maybe current, volts and Mah used would be missing). Then you'd have to write a little "hack" to send the reboot command to the 868 every 2-3 minutes or so. You can only send at a max of 19200 and the full message at 5Hz would be around 80% bandwidth usage. But you'd have so much more than what GPRMC offers.
I haven't posted a new version because I'm right in the middle of re-writing something and need to finish before posting.....
Can you post a screenshot of the serial data tab instead of the command line tab? I need to see what the GCS thinks the messages are. The checksums are correct so it should recognize them as NMEA messages.
What regional settings are you using? What language do you have selected and country are you in?
Another thing to consider is it's really inexpensive to add your own GPS unit if you need more information. Altitude is important in my view and is missing from GPRMC. It appears you can add lots of other NMEA messages to the Garmin GPS datastream, but if the drone has an auto-pilot onboard, you probably don't want to send the wrong messages to it....if it doesn't have an autopilot, then you should be able to enable GPGGA....and GPGLL if you want GPS time too...The 5Hz the 18 PC sends at should be plenty fast.
My GCS will listen for GPRMC. You'll get lat, long, speed, heading and date. I assume you only have 1 directional data from the plane to the ground, right? I can't find a lot of information about the PIXY...does it have an auto-pilot?
What did they give you to receive the signal from the plane? Is it an X-Bee or something else? It might be possible if you can do 2-way to send a PMTK command using the File, Heartbeats in my GCS to tell the GPS to send more information (Like GPGGA and GPRMC would be great) then you'd have sats, GPS lock, altitude and HDOP which is about everything you can get from a NMEA GPS.
I'd start off simple and download my GCS and try it at all the different baud rates from 4800 up to about 38400.... I doublt it's set any higher than that.
Replies
Ok, thanks for posting the .HKO file. Amazingly, the issue is due to a non-conforming NMEA message. Each line is supposed to end with <CR><LF> and every message in your log file ends with <CR><CR><LF>. This is incorrect, but it seems unlikely that Garmin would screw that up. So I suspect it's your UAV manufacturer that has done this. Anyhow, I can handle it now, so it's no problem.
The messages are also very erratic. They're arriving as often as twice a second and as slow as every 4 seconds. You've got a few problems here.
First, without GPGGA, my GCS will be useless. It will assume your altitude is 0m above sea level making Google Earth just bounce around like crazy.
Second, you appear to have a X-Bee 868 which has an RF max of 24K bps. So you should be using 19200 as a max. At 9600 and 5Hz, you're at 80% of bandwitdth capacity sending GPRMC and GPGGA. At 19200, you're at 40%. But here's the rub. The 868 have a limit of 10% duty cycle and this seems to have been poorly implemented by Digi and even less explained exactly how they calculate this value. That may have been the reason the developers of your UAV decided upon 38400 to try and get around this issue. Sending only GPRMC at 5Hz over a 38400 baud connection, is almost exactly 10%.
At this point, you need to decide what kind of range you need and if you want to hack the 868 for more functionality. With the amount of money you've spent on this project, what's another couple hundred dollars USD, right? Also, what kind of application are you performing? Is this a hobby project or a commercial one?
My "perfect" and cheap solution would be to buy a MTK GPS, ArduIMU V2 (this is the OLD one for the original ArduPilot) and a magnetometer. Then I would send the data from the IMU to the X-Bee using the ArduPilot legacy protocol. You'll have Pitch, Roll, Yaw, Heading, Altitude, Lat, Long, Sats, GPS Lock....pretty much everything you'd need for full functions on the GCS (maybe current, volts and Mah used would be missing). Then you'd have to write a little "hack" to send the reboot command to the 868 every 2-3 minutes or so. You can only send at a max of 19200 and the full message at 5Hz would be around 80% bandwidth usage. But you'd have so much more than what GPRMC offers.
I haven't posted a new version because I'm right in the middle of re-writing something and need to finish before posting.....
Can you post a screenshot of the serial data tab instead of the command line tab? I need to see what the GCS thinks the messages are. The checksums are correct so it should recognize them as NMEA messages.
What regional settings are you using? What language do you have selected and country are you in?
Another thing to consider is it's really inexpensive to add your own GPS unit if you need more information. Altitude is important in my view and is missing from GPRMC. It appears you can add lots of other NMEA messages to the Garmin GPS datastream, but if the drone has an auto-pilot onboard, you probably don't want to send the wrong messages to it....if it doesn't have an autopilot, then you should be able to enable GPGGA....and GPGLL if you want GPS time too...The 5Hz the 18 PC sends at should be plenty fast.
My GCS will listen for GPRMC. You'll get lat, long, speed, heading and date. I assume you only have 1 directional data from the plane to the ground, right? I can't find a lot of information about the PIXY...does it have an auto-pilot?
What did they give you to receive the signal from the plane? Is it an X-Bee or something else? It might be possible if you can do 2-way to send a PMTK command using the File, Heartbeats in my GCS to tell the GPS to send more information (Like GPGGA and GPRMC would be great) then you'd have sats, GPS lock, altitude and HDOP which is about everything you can get from a NMEA GPS.
I'd start off simple and download my GCS and try it at all the different baud rates from 4800 up to about 38400.... I doublt it's set any higher than that.