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Flight controller/display project — Parallax Forums

Flight controller/display project

There haven't been any new projects for a while. Unfortunatelly, I currently spend most of my time with boring work (PC software) so my own propeller projects also don't show much progress. Although it seems irrational to start another new project now as it might eat up even more time I need to keep my motivation up. And the best thing to do that is to do something crazy. So don't ask why, it's just a fun project.

Feature wish list:

  • artificial horizon (requires 6DOF accelerometer and 3D compass)
  • air speed (requires pitot tube and differential pressure sensor)
  • ground speed (requires GPS)
  • altitude (GPS with absolute pressure sensor as backup)
  • heading (compass + GPS)
  • position (GPS)
  • ground proximity "radar" (ultrasonic ping sensor)

I know there has been some similar P1 project some years ago. But I think sensor tecnology has improved a lot since then. MEMS accelerometers are far less accurate than the laser gyroscopes used in modern commercial aircrafts. So they are not suitable for a real inertial navigation system but together with a 3D compass they are good enough to provide an artificial horizon.

The first thing to do is to select the best fit of sensors. My memory is bad and the search function of this forum is also... I know that there has been some discussions about different types of sensors, so any pointers are welcome.

Comments

  • A first look at Mouser gave me these results:

    • ELVH15AHRNDCNSA4 as absolute pressure sensor
    • ELVH-M100D-HRRD-C-N4A4 for differential pressure

    They both offer I2C and SPI interface and 14 bits resolution for less than $40. 100mbar range translates to 250kn max airspeed.
    However, if somebody knows some sensors that are easier to use or more commly used, ideally with existing drivers, I'm open for suggestions.

  • YanomaniYanomani Posts: 1,524
    edited 2022-07-21 11:46

    Try querying any reasonable web-based search tool, as follows (forum's one always "sukyiakis" a bit), just substituting the appropriate AND-"quoted" terms:

    site:forums.parallax.com AND "6DOF" AND "accelerometer"

  • @Yanomani Thank you. In fact it's quite simple but until now I always thought asking people instead of the search engine yields higher quality results faster. But maybe I was just lazy...

    Ok, I see that the MPU-6050 and MPU-6500 are quite commonly used. Unfortunatelly, both are labeled "not recommended for new designs" and nowhere available. If found the ICM-42688-V which is in stock at Mouser but I have no idea which sensor is suited best.

  • ManAtWorkManAtWork Posts: 2,178
    edited 2022-07-21 13:48

    Bosch BNO055 seems also very interesting. The chip itself is also sold out but the Arduino shield is still available.
    As opposed to the MPU6500 the manetic compass is already included. The datasheet says it can dierectly output a vector for orientation in 3D space, acceleration and magnetic field each. Sounds simple.

    Edit: Same for the LSM9DS1 used in the Elev8 flight controller. The chip is sold out but the Sparkfun board is still available.

  • It seems like one of those round OLEDs that are popping up would be a good candidate for this kind of project. I recently bought one, but haven't had time to write a driver.

  • You mean one of those? It doesn't necessarily need to be round. If the additional info like speed and altitude are displayed next to the artificial horizon a bit more display area is required anyway. look here

  • @ManAtWork said:
    @Yanomani Thank you. In fact it's quite simple but until now I always thought asking people instead of the search engine yields higher quality results faster. But maybe I was just lazy...

    You're always welcome! And, please, forgive me if you understood something was going wrong with my answer! :smile:

    Please, go ahead whith continued asking for any advice, ever, forever; if there's no more good questions, how can anyone learn anything?

    Where's the fun??? :lol:

  • @JonnyMac said:
    It seems like one of those round OLEDs that are popping up would be a good candidate for this kind of project. I recently bought one, but haven't had time to write a driver.

    We'll all want to know which one you bought, so we can use your driver ;) , when its ready!

    dgately

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