Help on 2_7 program!

Hi all.. I have been trying out the new program and i found a few questions to ask.
  • First, for the debug of sensors input, what does it mean by airpressure_raw? does it mean by pitot pressure? I always receive a value of 400+, never exceed 500.
  • For the roll_sensor and pitch_sensor, are these values suppose to be accurate if I am testing outdoors + having z sensor for calibration?
  • For the airspeed, the value is in m/s right? If yes, can I just convert this value into knots for my airspeed indicator?
  • #define AIRSPEED_RATIO 0.1254 , how do I know whether I need to change this to 2?
  • #define AIRSPEED_CRUISE 13, is this value 13 fixed for every plane? if not, how do I know how much I need?
  • for the PITCH_TRIM, if my plane require a trim to pitch down of example 10 degrees, do I put -10? Because I am using an airplane which is not level when on the ground. It's pitched upwards about 10 to 20 degree when stationary.
  • in the #define DEBUG_SUBSYSTEM 3, there is readings on pitch and roll, are these values in degrees? and why do I get VERY inaccurate values even testing outdoor?
  • for the location of the XY sensor, if I am placing the sensor at the back of the plane body with wire facing the front, what number should it be? The location of my XY sensor is very similar to the one shown in the photo below.

    four.jpg



For the heading indicator, does anyone know what can I do so that I can achieve the heading in degrees with respect to either true north or magnetic north?

More help will be needed..

Darren



You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • Developer
    Air pressure raw is the value from the sensor without the offset applied. The offset is the default resistance in the sensor.
    roll_sensor and pitch_sensor should be accurate. They may be multiplied by 100 if you are looking at the internal values vs what is presented to the Control Station over serial.

    airspeed internally is m/s * 100, the GCS gets in m/s, convert to any unit you like.

    #define AIRSPEED_RATIO 0.1254 - your static pitot can influence your readings. If your GPS says you're going faster than your airspeed is reporting, you can tweak this. probably no need to fuss.

    AIRSPEED_CRUISE 13 - this is a tricky subject. basically, how fast do you fly when you are cruising around - It is definitely airplane specific. My easystar cruises at 15mph or so with minimal throttle. convert that to m/s and you have your number.

    PITCH_TRIM - don't mess with this - leave it 0. It's for misaligned sensors.

    Sensor location is 0

    The XY sensor requires a clear view of the horizon. It's basically a thermometer. if it sees the same temp out of opposing windows, it thinks it's level. Once your plane is in the air you will be in better shape.

    Just make sure the values aren't jumping wildly around if you hold the plane still. that would indicate a short or loose wire.

    If you have issues, just disable the Z sensor in your config and try again. If you do, be sure spin the plane around before launch or do a few loops after launch.
This reply was deleted.

Activity