bolt

We’ve had an exciting year in 2021, and we’re eager to see what 2022 will bring ! Let’s see what’s in the pipeline and what we hope for this new year.

Products

The AI deck and Bolt out of Early Access

We’ve put a lot of efforts during these last months on working with the AI deck’s firmware and infrastructure. With great help of our intern Rik, we managed to make huge leaps, and hopefully sometimes in the coming months we’ll be able to share what we worked on. I can already tell you that the incoming release will bring some needed improvements on flashing on the GAP8 chip and improved image streaming! As the AI deck is one of the most challenging of our decks, we also hope to add an extensive tutorial (that we call the “mega tutorial”) to help you working with it.

Also we have started to push some framework changes to make it easier for you to make bigger drones with the Crazyflie Bolt. One of those are the persistent parameter system that we have recently implemented on the Crazyflie’s, so we will add more and more of these types of features. The hope is, is that we are able to provide some kind of assembly kit for a larger Bolt-based drone, of which we already did some initial battery investigations for.

Prototypes

Fun Fridays are usually our time to play around with new possibilities and prototypes. Marcus has already made great strides, and hopefully in 2022 we’ll be able to go even farther with those. Arnaud has also been working on the much waited new iteration of the Crazyradio, with a new chip and an improved communication protocol. Tobias, our dedicated hardware man, has also ideas down the pipes in the form of a brushless Crazyflie as we already showed in our future plans presentation of November’s BAMdays. Also we hope to initiate the design process of a new and improved version of the Crazyflie with more power and processing capabilities.

People and Collaborations

Last year we have continued our close collaboration with researchers at institutes and universities, to help them out with achieving their goals and contribute their work to our opensource firmware and software. It proves really fruitful, both for us and the people we talk to, so we hope 2022 will see yet again closer and newer connections.

We were really happy with our first own online conference, which helped us reconnect and talk to our community about all the awesomeness achieved with the Crazyflies. We hope to implement something similar on a more regular basis, to keep talking about collaborations, possibilities, and in general sharing all the work that’s been done on the platform. Those “lightweight” BAM should arrive soon, so keep updated if you want to join them!

Component shortage and productions issues

We expect to still deal with the component shortage, as it is expected to last for at least another year, even two. Production is therefore a continuous challenge, with a lot of unpredictability, and we will find better solutions to deal with it in 2022. Thankfully, we have good hopes on keeping good stock levels throughout the crisis, as we’ve increased our stock. We’ll of course keep you updated on any big updates regarding the crisis and how it is affecting it us.

Unfortunately, the component shortage also means that it’s harder to make prototypes. It’s difficult to find and/or buy just one chip, so it causes delays in our creative hardware developments. It is what it is… but we will sure be able to find solutions – as we did during our 10 years’ history!

Anything else?

Of course our heads are always full of ideas and we are passionate to work on anything! We have ambitions in developing a simulation for our users or CI, doing more measurements with the new thrust stand or adding further improvements to our documentation and tutorials. And we might also meet new interesting people (digitally or in person?) who might give us enough inspiration to start something completely new! Soon we will have our quarterly meeting, where we try to herd and select our passions and ideas into conceivable plans and actions.

With all these exciting projects, we’re really excited to see what 2022 has in store for us! I hope you too have an awesome year 2022.

The Crazyflie parameter framework provides a way to get, set and monitor parameters in the quadcopter. Examples of a parameter include which effect the LED ring will display as well as which controller to use for flight.

The parameters have default values and up until now have been reset to those default values on each restart of the Crazyflie. This has not been seen as much of a problem (Or has it? Let us know!) since most use of the Crazyflie platform has been session based and the need for persistent parameters has been low. Our work with getting the Crazyflie Bolt out of early access has however changed this need.

The Crazyflie Bolt kit

The Bolt will need different values for the tuning parameters for controllers and being forced to set these on each boot would be pretty annoying. And since we want the Crazyflie Bolt and the Crazyflie 2.1 to share the same firmware, persistent parameters would come in handy.

Fortunately the Crazyflie includes an EEPROM (Electronically Erasable Programmable Read-Only Memory) which we can use to store parameter values and have them survive restarts of the quad.

So this means, with the latest branches of the firmware and the python library, you can set values of a persistent parameter, store it to EEPROM, and the parameter will keep its values across reset and even across firmware upgrades.

Persistent Parameter API

Not all parameters will be able to be persistent and stored in the EEPROM. We have added a way to declare a parameter as persistent in the firmware:

PARAM_ADD_CORE(PARAM_UINT8 | PARAM_PERSISTENT, effect, &effect)

This will allow the new API added to our python library to be used with this parameter. The API consists of three actions:

  • Getting the state of a persistent parameter
  • Storing the current value of a persistent parameter
  • Clearing the stored value of a persistent parameter

The state of a persistent parameter consist of three pieces of information:

  • Is the value stored or not
  • The default value of the parameter
  • The stored value of the parameter

Setting a value, using the regular parameter API, is not enough to store the value to the EEPROM for a persistent parameter, you need to be explicit. A special API call is needed to store the current value to memory. And to stop storing the value you need to use the clear API action.

Python API

The above choices corresponds to three methods in our Python API:


def persistent_get_state(self, complete_name, callback)

Get the state of the specified persistent parameter. The state will be returned in the supplied callback. The state is represented as a named tuple with members: is_storeddefault_value and stored_value. The state is None if the parameter is not persistent or if something goes wrong.


def persistent_store(self, complete_name, callback=None)

Store the current value of the specified persistent parameter to EEPROM. The supplied callback will be called with True as an argument on success, and with False as an argument on failure.


def persistent_clear(self, complete_name, callback=None)

Clear the current value of the specified persistent parameter from EEPROM. The supplied callback will be called with True as an argument on success and with False as an argument on failure.


Example code

We have also added an example script that will showcase the functionality, it will list the state of all persisted parameters in the firmware, and will store and clear some of them. The output when run against current master is:

$ CFLIB_URI=radio://0/80/2M/E7E7E7E7E8 python3 examples/parameters/persistent_params.py 
-- All persistent parameters --
sound.effect: PersistentParamState(is_stored=False, default_value=0, stored_value=None)
ring.effect: PersistentParamState(is_stored=True, default_value=6, stored_value=2)

Set parameter ring.effect to 10

Store the new value in persistent memory
Persisted ring.effect!
The new state is:
ring.effect: PersistentParamState(is_stored=True, default_value=6, stored_value=10)

Clear the persisted parameter
Cleared ring.effect!
The new state is:
ring.effect: PersistentParamState(is_stored=False, default_value=6, stored_value=None)

You can count on more parameters to be marked as persistent in the near future. Hopefully this will be useful for you! Please report any issues you find!

Happy Hacking!