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Questions about pixhack v5

pixhack-v5

(tridge) #14

yes, yellow flashing just means it isn’t armable. I think that is the same colours you would get on the built-in RGB LED on a Pixhawk1.


(Chris Olson) #15

I am still testing the components on the bench before installing in a helicopter. I was curious about the range of the WiFi telemetry radio. I powered the unit and walked across the field with my tablet connected with QGC. At 400 meters I still had a decent signal. I assume that radio could be used with a standard WiFi repeater with a high-gain or directional external antenna.


(tridge) #16

that’s better range than I expected.
Please watch out for R/C interference though. You’ll probably be OK, but some WiFi adapters interact very badly with some R/C protocols.


(Chris Olson) #17

I tested that this morning and there does not seem to be any interference between the two systems. I also tested the CUAV WiFi telem radio with a standard off-the-shelf WiFi repeater, and it works fine. But I’ll know more about the capabiilties of this system when I begin flight testing it, which will be later today.


(Chris Olson) #18

The Pixhack V5 is proving to perform flawlessly in a helicopter.

I’ve never had a chance to experiment with a WiFi telemetry radio before so the CUAV PW_Link radio is quite interesting. I tried a more extensive experiment. CUAV advertises the practical range at about 400 meters. But using a standard off-the-shelf WiFi extender at the ground station equipped with a high-gain patch antenna I connected to the helicopter with two different laptops, plus my Android tablet, all simultaneously thru the WiFi extender. I set up the WiFi extender to connect to the helicopter’s PW_Link radio.

I flew the helicopter out to 864 meters downrange distance and never lost the link on any of my three ground station computers. The helicopter was at an altitude of 33 meters. The external antenna on the PW_Link radio is stuck to the bottom of the helicopter frame with the included foam tape on it. The WiFi extender indicated a signal strength of 31% at 864 meters. The antenna I was using is a cheap Cisco AIR-ANT3549 9dBi gain directional type.

I have experienced no interference with my 2.4GHz RC radio whatsoever.

I haven’t been able to get the Pixhack V5 to mess up in the electric. So we’ll put it in the Raptor 716 gasser next. The PW_Link radio continues to impress me. I wonder if FPV video could be put on that WiFi link? It has typical MavLink latency. But it has me interested enough that I might get a CUAV Hack Link and try it, plugged into the HDMI port on a GoPro.


(Jakob Schmidt) #19

The wifi-link performance is interesting. I got one with my Pixhack V3 and A) was concerned about 2.4ghz interference and B) didn’t expect it to have any sort of range.
Given it’s small form factor, I may actually try to install it!


(Chris Olson) #20

It was designed to make it simple to connect to the vehicle with a mobile phone or tablet over short range. But a ham radio friend and I have played with wifi routers before to see how much range we could get with both commerically made and homemade antennas without dropping packets. In an environment with a lot of RFI it usually won’t get too far. But when you have LOS with antenna height and a relatively clean band the range can be a couple miles or more reliably with 5-10mW at the final amplifier stage of the transmitter with a good antenna. DJI’s Lightbridge system uses 2.4GHz at less than 20dBm with pretty good results so I’m not done playing with it yet to see what it can do :grinning:


(Luís Vale Gonçalves) #21

I have no idea what firmware is loaded on the CUAV PW_Link.

I might get some time to try to flash the new firmware that Tridge did to see how it behaves.

I guess the difference between this CUAV PW_Link ESP8266 and the one that was supplied with the PixRacer is the external patch antenna, which might improve the performance…


(cuavle) #22

HI,ChriOlson

      Can you give me the source video for your pixhack v5? A few days ago you seemed to have made a test flight.

(Chris Olson) #23

Have made several test flights. The BIN log is quite large and won’t post here. I sent it to you via private email.

Thanks!


(tridge) #24

I’d like the log too. Maybe you could put it on a google drive or similar?


(Chris Olson) #25

@tridge here is the log file
https://drive.google.com/open?id=13qPp4pE_SEySoNXByMNhEjZuJgN4H3PN

Luis said you are aware that the ChibiOS boards are not putting a date stamp (other than Dec 31, 1979) on the log files. I am now testing the board in a gas helicopter so I can fly it longer. Very impressed with how well the IMU’s agree with each other with the Pixhack V5. Copter 3.6 seems to be a little overly sensitive for GPS glitches and IMU’s not agreeing even in pre-arm state on the ground before anything is started on the heli with my other boards. I have not had that problem with the Pixhack V5 at all, but it’s hit and miss with my Pixhawks.

Another tester we are working with on heli beta testing noted that his Pixhawk 2.1 that flew fine on AC3.5 fails to arm on 3.6-rc2 due to inconsistent accel’s and bad GPS health messages. Even after a recalibration of the accels it refuses to arm.

20180613_203747-1


(Hugues) #26

Will you make a version of this CUAV V5 but in a “pixhawk1” form factor ? (This Pixhawk2.1 inspired form factor is quite unpractical for integration in small spaces like most drones are).


(brandon macdougall) #27

For the sake of discussion I can confirm chopy gps flights on the mRo x2.1 px4-v3 chibiOS rc-2. I can get it to arm but the FC is not happy. I also reset the FC configs to be sure… Nuttx 3.6-rc1 seems to fly well.


(Chris Olson) #28

The one that won’t arm is running Nuttx. The board in this thread, the Pixhack V5, flies perfectly with ChibiOS and I have not seen a single EKF or GPS error with it.


(brandon macdougall) #29

Good deal that it’s working well. My Cube/Spektreworks custom board is also flying well in chibiOS rc-2 but not on the older build. Sorry for off topic. I was thinking about testing the Pix hack v5 but I need to have external leds and usb so it’s on hold for me.


(Nathan E) #30

I don’t think the drivers have been built on NuttX; a big reason for the push to ChibiOS was in part because it was so easy and quick to get new boards running (IIRC).


(tridge) #31

yes, that is fixed in master now

that could be just luck as well. Individual IMUs do vary in their temperature sensitivity.

That is odd, as the drivers are identical. All I can suggest is to get comparitive DF logs with LOG_DISARMED=1 to see what the difference is.


(mpjf01) #32

The links above seem to be to websites in Chinese. Can someone please tell me where to see an English version, or how to change what I am seeing to English if that’s an option.


(cuavle) #33

Sorry, we are trying to create English instructions

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