CodeChief
commented
9 years ago I heard this feature is being worked on indirectly by people currently trying to get generic support for I2C into APM. It's mixed in with the requirement for faster ESC update, such as OneShot125 and other alternative interconnects like CAN.
Why indirectly? Because if you read this https://github.com/sim-/tgy/issues/64 and use an I2C variant of the SimonK firmware like this one adapted by balrogk1n of RC Groups here http://www.rcgroups.com/forums/showthread.php?t=2032252 you will get both RPM and temperature without any additional sensors!
The video posted by him here https://vimeo.com/78793047 is impressive. It looks like exactly what we want. The best part is we should also get the high speed update together with all the additional information. From the comments there I gather each ESC manufacturer and model has it's own capabilities, is more or less difficult.
Such complexities need to be hidden away from the user. That's a reason why I suggested some kind of GUI selectable profile (in an earlier discussion about OneShot125 and I2C) when implementing smarter ESC interconnects in APM. The community could help build the profiles, so we get a nice drop-down list of almost every common ESC model for the average user to just select then get the full capabilities from their ESCs.
So to APM devs please expedite the re-factoring of the ESC code (last I heard some kind of more generic splitting of the code was required) and I2C support, because we get a back-channel that will enable a load of other features together with it!
Besides being good to look at and log for problem diagnosis, I could imagine some kind of smart motor control like overspeed and overheat prevention, predictive motor failure detection (emergency landings) and overall performance/optimization indication (e.g. detection of sync issues). How cool would all that be?! :-)
marcmerlin
WickedShell
lzl200102109
gotmynina
IamPete1
I saw with @tridge and a bunch of 3DR folks at the recent ELC that there was support being added for a quadcopter ESC that reports RPM data to the flight controller. However, it's only a 20A ESC, which is entirely useless for my high power plane which uses 80A :)
Castle ESCs already report RPM on a 4th white wire, and can actually report a lot of information as explained here: http://www.castlecreations.com/support/documents/castle_link_live_2.0.pdf (page 6)
For people with any other ESC, you can just add this $18 sensor: http://www.alofthobbies.com/frsky-sp-rpm.html and you even get 2 free temperature logs, like how hot your ESC and motor are getting.
It would be awesome for APM to add support for widgets like this and add it to the data logging. Adding that generic support would even allow adding RPM support for quadcopters without replacing their ESCs,or using their existing ESC if it reports RPM already.