Is this an older engine like a MW54 or a JetCat single stage?
It may be possible tridge has something like this working. If so I’m not aware of it. Rob may be referring to some basic governor code he did in AC3.4 that may or may not have been flown and tested, I’m not sure
Chris, its a Jakadofsky Pro X
Unless I’m misunderstanding something, this already exists.??
Look at the RPM parameter in this log:
https://www.dropbox.com/s/a1m0mvhhmm48wi6/2018-01-14%2014-41-10.bin?dl=0
I’m using the hobbywing RPM sensor mentioned earlier.
Jakob, The sensor your using pulls RPM from the brushless motor. What we’re talking about is a sensor that pulls actual rotor RPM directly from the main rotor gear and feeds that into the pixhawk and the associated code to take that RPM and control throttle and in the event of engine failure that RPM could also be used in-conjunction with collective pitch in order to preform a auto-rotation
Right!!
However, that should still work with the hall effect sensor? (I keep meaning to buy one of those Align ones)
OK, I had to get up-to-date on this. It appears the code reads pulses or PWM. If your hall effect sensor puts out a pulse per revolution, it should read it on pin 54 and set the RPM_TYPE to 2. 50Hz will show 3,000 rpm, so it appears the scaling would be 1.0 with a single magnet on the auto gear. Any hall effect sensor should work the way I read the code.
Hi Chris,
To combat the growth in number of parameters you might create a new group containing an ENABLE parameter with the AP_PARAM_FLAG_ENABLE flag. This way, the parameters in the group are only displayed to the user when the feature is enabled. https://github.com/ArduPilot/ardupilot/blob/master/libraries/AP_Soaring/AP_Soaring.cpp is the example I’m most familiar with.
Sam
Wow, thanks for that tip, Sam. I didn’t realize we could do that. That will certainly be helpful. Heli does not have a lot of params compared to some of the other things. But it is still good to try to keep the number of params that have to be downloaded to the GS at boot time to a minimum.
Hi Chris,
Sorry to jump for this old post. I am working on finding a way to log data of the physical rotation speed of the motor to the pixhawk. My drone is a multicopter (quadcopter), flying with a pixhawk 6X, and having a Dshot ESC’s. I am a bit confused between the data that I can log in from ESC which i think its the electric rotational speed and the physical rotational speed that can be measured by an external sensor.
Q: Which one is more accurate?
If a sensor to be mounted externally is more accurate, then this is the page that I should follow: RPM Measurement — Copter documentation? Would you mind recommending me a sensor that you might already tried?
Q: If the ESC Dshot feedback is accurate, then could you please guide me how can I set it up so that I can get the data from the sd card?
Since I am completely a beginner in this topic, I would highly appreciate your guidance.
Thank you
Depending on what kind of ESCs you’re using you can use Bi-Directional Dshot. The ESCs will need to be on BLHeli32 (or one of it’s replacments) or BlueJay firmware.
The RPM sensing talked about here isn’t really appropriate for a multirotor with modern ESCs. Helis are a different situation.