Airspeed sensor not working

@vvid - we recently discovered the ms4525 airspeed driver error count was including more than just errors. Can you try again with master, or cherry-pick this commit? https://github.com/PX4/Firmware/commit/384e3bb6939b1c701bc8b78ff0264e7a908e87c5#diff-bcf64e5798d7c4b9cbf7fd62e5a0bedb

I hope I can try it tomorrow, Iā€™m super busy this weekā€¦

Hi all,

Sorry for posting in this old topic, but my question fits best here, I guess.

Iā€™m trying to set up a VTOL similar to the Fun Quad Cub VTOL. Iā€™m using the Eagle Tree V3 Airspeed sensor, which used to work fine up until 2 weeks ago. It is connected to the I2C input of the Pixhawk using an I2C splitter. When Iā€™m trying to do an airspeed sensor calibration, it says:
[cal] No airspeed sensor found.

I checked this with two different pixhawks (2.4.8) and tow different Eagle Tree V3 airspeed sensors. A hardware issue can thus be excluded.

When I change the ā€œSENS_DPRESS_ANSCā€ Parameter to a value other than 0, it would start the calibration, but stop with the error message:
[cal] calibration failed: airspeed

Does anyone have an Idea of how to solve this problem?

Could you verify the firmware version when it was working and the current one? I had a similar issue with an ET airspeed sensor. Didnā€™t even consider that it might be related to the upgraded firmware so Iā€™m curious. Thanks.

Which Firmware version are you using now and which Pixhawk?

In the 1.7.3 Release the for the Pixhawk with the silicon error the Eagle Tree driver is not included due to flash restrictions.

@michbeck Just wanted to confirm what @acfloria saying that ET airspeed sensor is not supported in 1.7.3. That would explain why it was working 2 weeks ago, as I ran into the same issue. I tested this morning and confirmed that in fact my ET airspeed work and calibrates in 1.6.5 but not recognized at all in 1.7.3. Iā€™m wondering if this should be filed as an issue or was it a conscious decision by dev team to discontinue driver support for it? @LorenzMeier @dagar @acfloria Thoughts?

@michbeck If you upgraded to v1.7.0 or higher, go to FW_ARSP_MODE and Enable it and see if that makes it work. If that doesnā€™t, and you have a 32-bit board, youā€™ll need to use px4fmu-v3_default.px4 (not v2).

Good luck

We are having the same issue to get the Airspeed sensor to work using the 4525D digital sensor plugged into the i2C port. Using the default parameters set for the AS sensor it just reports ,
[cal] calibration started: 2 airspeed
[cal] No airspeed sensor found

We are suing Generic Quad Plane VTOL and just installed QGC3.3 daily build yesterday. Is there any settings in parameters we need to manually adjust to make this work?

I saw in another post an issue about the voltage on the i2C being 3v and the is 5vā€™s? Is this still relevant?

  • Try swapping the two middle wire.
  • Feel the sensor to make sure itā€™s not getting warm/hot. If it is, the positive and negative wires may be backwards.

Good luck.

no luck, still didnā€™t work

Hi everyone!!

I have been also struggling with getting my airspeed sensor working. I have done a lot of searching but found no solutions yet. Heres is my current set up:

Flight controller: Pixhawk 4
Firmware: PX4 1.8 (Running standard fixed wing aircraft)
QGroundcontrol version: 3.2.4
Sensor: px4 airspeed V1.3 (Sold by Holybro. Link: https://shop.holybro.com/digital-air-speed-sensor_p1029.html )

My issue is that when I click calibrate I receive these messages:

[cal] calibration started: 2 airspeed
[cal] No airspeed sensor found

Here are the things I have tried:
-Twisted all cables
-Tried different cables
-Swapped I2c lines
-Research and check params relating to airspeed sensor
-Drop logic level lines from 5v-3.3v (More on this)
-Through finding a sensor (Lost the link to it) sold specifically for the Pixhawk family, claiming that it was unique because it had a level shifter onboard that dropped the I2c lines from 5v to 3.3v. Implying that most other sensors ve their I2c lines at 5v. I looked at photos of it closely and it did have more components on it compared to all other px4 airspeed sensors on the market so this gave me mild justification to believe that my sensor has its I2c lines at 5v. A long shot, I know, but im looking for anything now. I have been struggling for a long time on this. For this reason I bought a I2c level shifter from sparkfun and wired it in to drop my I2c lines from what I believe to be 5v, down to 3.3v.

After all this I still get the same error and iā€™m pulling my hair out. Im not sure if im just being foolish and doing something incredibly simple wrong, or what else is going on, but any help would be appreciated. If your asking why I havenā€™t bought the other sensor that says its made specifically for the Pixhawk, its because I blindly closed the web page a week ago and of course, didnā€™t have it bookmarked.

Thank you in advance for any input, and if you know the sensor im talking about, a link would be much appreciated.

Ahh!!! Found the link to the sensor. M Robotics sells it.

  • Just curiousā€¦ what airframe have you selected?
  • Is FW_ARSP_MODE Enabled?

Are you referring to the two middle wires (Rx / Tx) or the two outer ones (+ / - voltage)?

Good luck.

Hi @rollys

  • I have the Standard Plane aircraft selected.
  • FW-ARSP-MODE is enabled
  • The SCL and SDA lines were switched. Pins 2 and 3 on the connector.

All of these were already true, thus the sensor still does not function.

I appreciate the response. :slight_smile:

I have the exact same issue Ben. I have a Pixhawk 4 and had the MS4525DO sensor (the normal 5V one). I read the same articles as you it seems and thought it must be a voltage issue so I bought the next gen airspeed sensor - the MS5525 because it looked like 3V would be sufficient.

MS5525

Unfortunately that didnā€™t work either so now I have 2 airspeed sensors, both of which throw up the error:

[cal] calibration started: 2 airspeed
[cal] No airspeed sensor found

In short, I wouldnā€™t buy the MS5525 hoping that will fix it :frowning:

Iā€™m stuck until someone much brighter than me solves this.

Al

Just for the record, Iā€™m also having this problem with the SDP3x Airspeed Sensor not detected by Pixhawk. I have it plugged into the I2c port on a Pixhawk 2.1 Cube using the PX4 1.8.0 firmware. Iā€™m trying to get the Generic Delta VTOL airframe profile working. It seems not to detect anything plugged into the I2c port.

Thing is, this sensor worked on previous firmware builds. I ran a test and loaded on Ardupilot and the sensor shows up so itā€™s a firmware problem. Canā€™t progress with out it. Would love to hear from the developer community and find a solution.

Is there a simple way to roll back to a previous PX4 firmware build?

it was due to interchange of ports , the ports order from sending end of air speed sensor was 5v,SCL,SDA,G but on the other end also must be in same order (once check on other side of the wires arranged propely or not ) the 5v and scl pins on other side of my sensor has been interchanged . after solving that issues air speed sensor will be detected but it shows some negative values , for this u need to inverse the sensor tubes and test it again , now it works great .

hi there please take a look at:

Hi, I have a same issue with same airframe but my QGC is now 4.1.4, did you solve that issue, if yes, could you make me know. I introduced my error here If you wanna look deep inside.

Hi how did you solve this