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I am doing some researches about crazyflie 2.0
and I should let it fly and hover at some positions by the client not the contorler.
And I understand the mode and the contorl way. same like I just need modify the source code in some simple ways.
but I modify the file of "commmer.c" and "crtp_commander_rpty.c" still unable to accurately control the drone to an accurate location.


and if I want to contorl the drone should I use the FreeRTOS? or just modify the source code?
all dears please help me
please give me some help or hints.
Thank you!!

Hi!

The Crazyflie has no real notion of its position in space, the on board sensors (accelerometers and gyros) can be used to give a rough idea of its movements but lacks the accuracy for long term position awareness. To be able to hover at a spot without user interaction (autonomous flight) the Crazyflie needs better positioning information. There are several ways to provide this:
1. the easiest (and cheapest) solution is to use the optical flow deck (https://store.bitcraze.io/collections/d ... ow-deck-v2). It gives information about motion in X and Y, and the absolute distance to the ground. This will help the Crazyflie to understand where it is in relation to its starting point.
2. more complex (and expensive) solutions include absolute positioning systems such as LPS (https://www.bitcraze.io/products/loco-p ... ng-system/), the light house system or external systems such as mo-cap for instance.
The choice of technology depends on requirements and budget.

When you have a Crazyflie with some form of positioning support, the easiest way to control it is from a python script. There is no need to modify the firmware, unless you find it interesting and fun . There are example scripts in https://github.com/bitcraze/crazyflie-l ... r/examples, for instance autonomousSequence.py. This is a good starting point to explore and getting started with autonomous flight. We have just added some step-by-step guides in https://www.bitcraze.io/documentation/r ... on/master/ that is useful if you decide to use the flow deck.

Thank you very much for your reply !!
And i want to know that have not some possibility that i do not need with python scrip or LPS just modify the firmware(src) to let the crazyflie hover?
I just want let the crazyflie take hover in the sky maybe just 50cm upon the ground with 1min.this is all I want.

I know it very complex but this is only way I can do.so please tell me is this feasible？

Thank you very much again for you reply!!!

Check out this tutorial for hovering through the cfclient: https://www.bitcraze.io/documentation/t ... flow-deck/
You do need a controller for this though.

thanks for your reply
I wander can I hover automatically to complete my research by z-ranger deck v2?
I find use this one can do it with the cfclient

thank you very much

For hovering you need the flowdeck v2. With the zranger you only have position estimate in the z-axis but for hover you need to have a position/velocity estimate in the x and y axis as well