# Px4flow sensor issue

**URL:** <https://discuss.px4.io/t/px4flow-sensor-issue/11308>\
**Category:** Pixhawk\
**Created:** [June 6, 2019, 6:54am UTC](https://discuss.px4.io/t/px4flow-sensor-issue/11308 "2019-06-06T06:54:43Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![acpl00](https://discuss.px4.io/letter_avatar_proxy/v4/letter/a/9dc877/32.png) [@acpl00](https://discuss.px4.io/u/acpl00)\
**Post date:** [June 6, 2019, 6:54am UTC](https://discuss.px4.io/t/px4flow-sensor-issue/11308/1 "2019-06-06T06:54:43Z")

</div>

Dear people.

I have the following setup:

```auto
-PixHawk 4 mini
-PX4FLOW V2.3
Jetson TX2
-GPS

```

First I have set the version master to the pixhawk 4 mini

The communication from the companion board (Jetson TX2) to the groundcontrol station is via wireless.

I use EKF2 and I had Set

```auto
 SENS_FLOW_ROT to 270 degrees, default 
 EKF2_AID_MASK to use optical flow and GPS
 EKF2_HGT_MODE to use the range finder

```

So far I could see in the mavlink inspector the:

```auto
  -optical_flow_rad 
  -local_position_ned

```

Then after some few tests with the drone where I have disabled the px4flow. Then, I upgraded the `pixhawk 4 mini` with the version `1.9 stable` over qgroundcontrol station.

Then, the flow sensor stop working I do not see any more the `-optical_flow_rad` in the mavlink inspector. I can see the leds blinking on the px4flow sensor.

The extras.txt in the /etc file of the SDcard of the pixhawk is:

```auto
mavlink stop-all
mavlink start -d /dev/ttyS1 -b 921600 -r 1000 -m onboard
mavlink stream -d /dev/ttyS1 -s ATTITUDE -r 1000

I have read in the link  

https://docs.px4.io/en/sensor/px4flow.html  
 

`This does not work on FMUv5 (Pixhawk 4) for PX4 versions less than 1.9.0. All other PX4/Firmware versions should work.` 

This means that the version 1.9.0 stable does not support PX4FLOW???

```

Any help or advise I really appreciate it.