Request: Integrate MPU9250 and BMP280 into VFRnav

VFRnav Support
1

@Hermann,

it would be awesome if the above chipsets, i.e. the 3-axis gyro + the tri-axis accelerometer and the BMP280, which for example are on the GY91 board, could be read/integrated into VFRnav.

Why, and for what?:

  • MPU9250 – not all aircraft have an artificial horizon built in. This would provide an inexpensive solution. Many Stratux units have this chipset installed, at least all those that have passed through my hands. The Stratux itself has long been interpreting the aforementioned MPU9250 and displays it as a horizon in the WebGUI. …an applet in VFRnav, e.g. a small icon in a corner, would be superb :folded_hands:

  • BMP280 – the sensor measures air pressure barometrically and provides the data. Also a classic, which is fitted in Stratux units or, in my case, additionally in the TTGo T-Beam. VFRnav can already read baro data from the phone (since it has such a sensor). So why not read the sensor from the Stratux? …the Bosch sensor should also have higher measurement accuracy than a phone.

→ …as always: I’m ready for pre-development and trialling. :star_struck::+1:

Yes, I know…for the phone pilots the display will become smaller with the integration of such features. Therefore, as always in VFRnav: optionally switchable via a control.

Pilot greetings, simply fly

Karsten

2

Hi Karsten,

after AHRS data support – i.e. the attitude information for the artificial horizon – was introduced in VFRnav 4.15, I’ve now been able to look into your second suggestion as well.

My latest finding: Stratux already provides additional altitude information in the NMEA sentence $PGRMZ. If a baro sensor is fitted, this value corresponds to the baro altitude referenced to the standard atmosphere. That would be the perfect basis for an external pressure measurement for the altitude display in VFRnav.

The problem is: if there’s no baro fitted in the Stratux, it sends the GPS altitude in the same sentence.

I therefore still need to examine more closely how to reliably distinguish the source of the PGRMZ altitude. Maybe someone has an idea?

Why all this?
With the current pressure, which could be derived from the PGRMZ sentence, VFRnav could display the baro altitude according to the entered QNH – which, as we know, is much more accurate than GPS altitude. In addition, a variometer could also be implemented this way.

That’s it on this topic for now.

Enjoy your holiday @KBfly :slightly_smiling_face:

Hermann