I am using Ardusub 4.2dev firmware on Pixhawk 1. However, the depth pressure sensor (bar30) doesn’t seem to be registering. I have changed the BARO_PROBE_EXT to 768 but the SCALED_PRESSURE2 doesn’t show up in the qGC Mavlink Inspector. How can I make 4.2dev register the bar30 sensor with the Pixhawk 1?
Thanks in advance for your help.
Tim
Hi @TMJ,
I just installed 4.2.0-dev, set BARO_PROBE_EXT to 768, rebooted the vehicle, and my Bar30 was registering fine. Perhaps try rebooting, if you haven’t already? 
Thanks Eliot. This was for the Pixhawk 1?
Yes
So I’ve tried rebooting and I’ve tried two different Pixhawk 1’s and two different Bar30 sensors.
Is there another parameter that I need to change?
Here are the baro related parameters I’m using:
| 1 | 1 | BARO1_DEVID | 721186 | 6 |
|---|---|---|---|---|
| 1 | 1 | BARO1_GND_PRESS | 98664.031250000000000000 | 9 |
| 1 | 1 | BARO1_WCF_ENABLE | 0 | 2 |
| 1 | 1 | BARO2_DEVID | 0 | 6 |
| 1 | 1 | BARO2_GND_PRESS | 102282.000000000000000000 | 9 |
| 1 | 1 | BARO2_WCF_ENABLE | 0 | 2 |
| 1 | 1 | BARO3_DEVID | 0 | 6 |
| 1 | 1 | BARO3_GND_PRESS | 0.000000000000000000 | 9 |
| 1 | 1 | BARO3_WCF_ENABLE | 0 | 2 |
| 1 | 1 | BARO_ALT_OFFSET | 0.000000000000000000 | 9 |
| 1 | 1 | BARO_EXT_BUS | 1 | 2 |
| 1 | 1 | BARO_FLTR_RNG | 0 | 2 |
| 1 | 1 | BARO_GND_TEMP | 0.000000000000000000 | 9 |
| 1 | 1 | BARO_PRIMARY | 0 | 2 |
| 1 | 1 | BARO_PROBE_EXT | 768 | 6 |
| 1 | 1 | BARO_SPEC_GRAV | 1.000000000000000000 | 9 |
My BARO_PRIMARY is set to 1 (2ndBaro in QGC). Everything else is the same besides the calibration values
Hi Eliot,
If I try to change BARO_PRIMARY from 0 to 1, save and reboot in QGC, it shows BARO_PRIMARY=0 again. If I manually change the param file value of BARO_PRIMARY to 1, upload it and reboot, it shows BARO_PRIMARY=0 again.
Any thoughts on how to permanently change BARO_PRIMARY to a value of 1? I suspect that may be why my Pixkhawk 1 is not registering the Bar30.
Thanks,
Tim
My suspicion here is that it’s not allowing you to change the value because the sensor is not being detected, rather than the other way around. That said, I’m not sure why the sensor wouldn’t be being detected, so I’ve brought this up internally in case someone else has some idea.
Does it work properly when using the stable or beta firmwares instead of the development one?
Eliot seems to be on the right track. the fact the BARO2_DEVID is zero implies that there’s no second sensor detected. are you using regular wire lengths?
Yes it does appear to be recognized with the stable version.
Yes I am using the standard length that comes with the Baro30.
Hi @TMJ ,
Did you manage to fix the issue?
Another suggestion would be to completely reset the parameters to defaults (parameters tab → tools button → reset all parameters to firmware defaults)
Yes, issue resolved. Set BARO_PROBE_EXT to 768 and reboot vehicle with BAR 30 sensor plugged in. Works for both Pixhawk1 and Pixhawk4.
Thanks for all your help everyone.
can you please share the link to download ardusub 4.2.0 dev firmware, im not able to find
Hi @Mourya, welcome to the forum
The -dev/latest firmware is rebuilt whenever there are changes to the master branch of the source code, and specific builds of it are not maintained long term.
The current ArduSub stable is 4.1.x, so originally the next minor version was expected to be 4.2.0, so the dev releases at that time were considered to be 4.2.0-dev. We have since decided to jump straight to 4.5 to realign the codebase with the other ArduPilot vehicle types, so current dev releases are considered to be 4.5.0-dev instead.
The latest developer build is installable through QGroundControl as the “Developer Build (master)” in the advanced settings, or as the DEV version in BlueOS’s Autopilot Firmware page, or can be downloaded manually from the firmware repository.
If for some reason you want to test a different point of development then you’ll need to clone the source code repository, checkout/revert back to the commit you want to roll back to, and build the firmware for your target board.