Author: Tobias

As pointed out in Daniele’s blog post about the PULP-DroNet we are collaborating on a AI-deck built around the new GAP8 RISC-V multi-core MCU. In the blog post you can find all the details around DroNet while here we will talk a bit about the AI-deck hardware. The AI-deck is similar to the PULP-Shield but with some optimizations. One of the HyperFlash memory spots has been removed, the communication interface slimmed down and a ESP32 (NINA module) has been added for WiFi connectivity.

Latest AI-deck prototype

So all together this a pretty good platform to develop low power AI on the edge for a drone.

Features:

  • GAP8 – Ultra low power 9 core RISC-V MCU
  • Himax HM01B0 – Ultra low power 320×320 greyscale camera.
  • 512 Mbit HyperFlash and 64 Mbit HyperRAM
  • ESP32 for WiFi and more (NINA-W102)
  • 2 x JTAG for GAP8 and ESP32

Currently we are doing the final testing of the hardware and hopefully we will launch production in the end of October. If production goes according to plan we hope we can offer it as an early access product just before X-mas. Make sure to come back and check the blog for more information about the progress as well as pricing.

We have now come to a the point were we will start manufacturing of the Crazyflie Bolt, Formally known as the RZR. You might wonder why we changed the name… Well the RZR more implies it is a Racer quad and it really isn’t. This is mainly because of the design in power distribution which is limited to around 8A per motor. However by using your own PDB it will work well for that too. But that is not the intention, it is more intended to have the strengths of the Crazyflie 2.1 but in a slightly bit bigger package. Therefore we wanted a better name for it and after a brainstorming session we came up with the name, Bolt. Both as it is a Crazyflie building block, a bolt used to fasten things, but also because it has the potential to be fast, as in a lightning bolt. Great name right :-)

The CF-Bolt development has been pushed back many times because of other more promising products, but finally it is getting here. If things goes according to plan, the Crazyflie Bolt should be in our shop in Aug-Sept. If you want to read up on the history and what it is all about read about the first flight to the almost-final prototype here.

A quick recap of the features:

  • Fully compatible with the CF2 firmware, expansion decks as well as radio.
  • Connectors to attach motor controllers (also possible to solder though) so it is easy to build and repair.
  • Power distributions built into controller board. (Max ~8A per motor controller) with XT30 connector.
  • Motor controllers can be switched off by the system (MOSFET) so the system can go into deep sleep and only consume around 50uA.
  • Voltage input 1S-4S (3V to 17V).
  • Standard mounting (M3 mounting holes spaced 30.5mm in a square).
  • External antenna for increased range.
  • SPI connected IMU (BMI088) for minimum latency.

Only a week left until we stand in our ICRA booth in Montreal and give you a gimps of what we do here at Bitcraze. As we have been writing about earlier we are aiming to run a fully automated demo. We have been fine tuning it over the last couple of days and if something unpredictable doesn’t break it, we think it is going to be very enjoyable. For those that are interested in the juicy details check out this informative ICRA 2019 page, but if you are going to visit, maybe wait a bit so you don’t get spoiled.

Apart from the demo we are also going to show our products as well as some new things we are working on. The brand new things include:

AI-deck, Active marker deck and Lighthouse-4 deck
  • AI-deck: This is a collaborative product between GreenWaves Technologies, ETH Zurich and Bitcraze. It is based on the PULP-shield that the Integrated and System Laboratory has designed. You can read more about it in this blog post. The difference with the PULP-shield is that we have added a ESP32, the NINA-W102 module, so that video can be streamed over WiFi. This we hope will ease development and add more use cases.
  • Active marker deck: Another collaboration, but this time with Qualisys. This will make tracking with their motion capture cameras easier and better. Some more details in this blog post. Qualisys will have the booth just next to us were it will be possible to see it in a live demo!
  • Lighthouse-4 deck: Using the Vive lighthouse positioning system this deck adds sub-millimeter precision to the Crazyflie. This is the deck used in the demo and could become the star of the show.

Adding to the above we will of course also display our recently released products:

  • Crazyflie 2.1: The Crazyflie 2.1 is an improvement of the Crazyflie 2.0 but keeping backward capability.
    • Better radio performance and external antenna support: With a new radio power amplifier we’ve improved the link quality and added support for dual antennas (on-board chip antenna and external antenna via u.FL connector)
    • Better power button: We’ve gotten feedback that the power button breaks too easily, so now we’ve replaced with a more solid alternative.
    • Improved battery cable fastening: To avoid weakening of the cables over time they are now run through a cable relief.
    • Improved sensors: To make the flight performance better we’ve switched out the IMU and pressure sensor. The new Crazyflie uses the drone specialized sensor combo BMI088 and BMP388 by Bosch Sensortech.
  • Flow deck v2: The Flow deck v2 has been upgraded with the new ST VL53L1x which increases the range up to 4 meters
  • Z-ranger deck v2: The Z-ranger v2 deck has been upgraded with the new ST VL53L1x which increases the range up to 4 meters
  • Multi-ranger deck: The Multi-ranger deck adds VL53L1x sensors in all directions for mapping and obstacle avoidance.
  • MoCap marker deck: The motion capture deck with support for easily attachment of passive markers for motion capture camera tracking.
  • Roadrunner: The Roadrunner is released as early access and the hardware is basically a Crazyflie 2.1 without motors and up to 12V input power. This enables other robots or system to use the loco positioning system.

You can find us in booth 101 at ICRA 2019 (in Montral, Canada), May 20 – 22. Drop by and say hi, check out the products & demo and tell us what you are working on. We love to hear about all the interesting projects that are going on. See you there!

As part of our collaboration with Qualisys we are helping them developing an active marker deck for their motion capture cameras. One of the major benefits with an active marker deck is that it can have an ID, thus it is much easier to track each Crazyflie in e.g. a swarm. Another benefit is an increased range compared to passive markers thanks to high power emitting IR LEDs.

Active marker deck mounted on a Crazyflie

We are currently only in the prototype stage but we have already managed to do initial fight tests so hopefully we can release it within a couple of months.

We will bring some prototypes to ICRA 2019, come and visit us and Qualisys to check the deck out.

As we have written about before we moved to a new office last month. One of the major reasons was the need for a bigger flight lab. This will enable us to do better testing and improve how we can develop things, especially our positioning solutions. Even though it is not a huge place, going from 4x4x3m to 8x8x3.5m and possibly 13x9x3.5m, is a great improvement for us. We call this great playground for the Arena as this is what it feels like for us :-). Very soon we hope to have our Qualisys MoCap system, Lighthouse and the Loco positioning running, maybe even at the same time.

The Arena

As a bonus this is a great pace to play HTC Vive VR games, we just need to get the wireless transmitter so we can make full use of the space!

One of the first flights with LPS Two Way Ranging

Today we received a bunch of MoCap marker decks which means they are now available in our shop. This is a handy deck for those that flies in a motion capture system as it is easy to create different configurations and move between Crazyflies.

The deck is designed in collaboration with Qualisys. We suggest using 6.5mm, 8mm or 9.5mm diameter reflective motion capture markers. Currently we don’t offer the markers but soon we will also offer a bundle together with markers.

The new Crazyflie 2.1

The Crazyflie 2.0 was released almost 4 years ago now. When we released it we wanted to avoid limiting our users in hardware. We over-designed it with lots of features and power we weren’t using at the time of release. We also put in the deck connector so we could keep users updated with new hardware without having to replace their Crazyflies.

Over the years there’s been thousands of users and lots of feedback on the product. Most of it great, but there’s of course also been issues that needed to be addressed. The original design concept is still working with new decks coming out and still free CPU cycles, flash and RAM. So instead of major updates we decided to focus on fixing the issues we’ve seen while keeping backwards compatibility for our users.

So today we’re really excited to announce we’ve released the Crazyflie 2.1! The updated version of the Crazyflie brings improved flight performance, better durability and improved radio stability.

Here’s a list of the updates:

  • Better radio performance and external antenna support: With a new radio power amplifier we’ve improved the link quality and added support for dual antennas (on-board chip antenna and external antenna via u.FL connector)
  • Better power button: We’ve gotten feedback that the power button breaks too easily, so now we’ve replaced with a more sturdy alternative.
  • Improved battery cable fastening: To avoid weakening of the cables over time they now run through a cable relief.
  • Improved sensors: To make the flight performance better we’ve upgrade the IMU and pressure sensor. The new Crazyflie uses the drone specialized sensor combo BMI088 and BMP388 by Bosch Sensortech. It lowers drift and avoids accelerometer saturation which makes the IMU more “trustable”.

It’s important to note that the Crazyflie 2.1 is a drop-in replacement for the Crazyflie 2.0. All spare parts and decks are compatible with both the Crazyflie 2.0 and the 2.1.

We even took it so far that the same binary can be flashed on the Crazyflie 2.0 and 2.1 without any special care. The binary will automatically activate the right drivers which means working with mixed groups of 2.0 and 2.1 isn’t a hassle.

When releasing the Crazyflie 2.1 we’ve also updated all the bundles to contain the new version. But even though you can’t get the bundles with the Crazyflie 2.0, there’s still some Crazyflie 2.0 units left from the last batch that can be purchased in the E-store.

Another hectic year has passed. We can’t believe it’s been seven years since our first blog post. Only missing a few Monday blog posts over these past seven years makes this post #375! Kind of impressing from a bunch of nerds that rather write code instead of communicative and fun blog posts :-).

As being the last blog post of the year we can’t think of anything better then summarizing 2018.

Community

The community is one of the big motivators for us. We are very, very thankful for your support! You keep us going!

Software

  • On the Loco positioning side there has been a lot of focus on TDoA, aka swarm positioning. During the year we managed to release TDoA2 and TDoA3 as experimental. Read more about the algorithms in their respective blog post.
  • The Crazyswarm fork was merged into master, thanks again USC ACT Lab!
  • Together with Qualisys we continued the work to add support for their MoCap cameras to the Crazyflie system.
  • It might not be correctly classified as software but we released a new front page!
  • Firmware and Software release 2018.10 packs a lot of new stuff.

Hardware

Logistics

We can’t summarize 2018 without a note about the logistics problems we had which made us move the stock to our office in Malmö. Who figured it could be that hard! For those that had to wait a long time for their packages, we apologize. The good news is that it is much better now and logistics will work flawlessly in 2019!, hopefully… :-)

In August we got invited by Marion from ETH Zurich to help out with this years PolyHack, that is organized by Telejob, and which theme was about drones. We really like this kind of events but our reality is that we normally don’t have enough time to participate. For this occasion though we had the opportunity to both have fun and see how our products work when used during an event like this. Two birds with one stone and the decision was made.  Together with one of the main sponsors ELCA, we organized the flying postman challenge:

Drones seem to be the future of post deliveries, but how is it going to work? Join us to reproduce a swarm of drones delivering parcels through a city to have a glimpse at this future!

The challenge the teams got was to deliver as many parcels within 5min in a miniature city, 4m x 4m, using Crazyflies. Since the Crazyflies can’t carry that much payload the parcels was just digital/imaginary but had to be picked up at a pick-up zone. They were allowed to use up to thee Crazyflies simultaneous to increase capacity. For more details checkout the challenge description.

To manage the challenge ELCA developed the CrazyServ which uses a REST API to control Crazyflies, wrapping the high level position commander, and to pick-up parcels. One nice benefit with a server is that it can keep track of which parcels has been picked up and been delivered making the scoring fully automatic.

Bitcraze part in the challenge was to bring drones, technical support and our loco positioning system to make up the 4m x 4m city. Or actually three of them, as there were going to be six teams competing for the victory. The initial information was that the three systems would be installed in separated rooms, far away, but we ended up having them side by side. That left us with some live-hacking, changing from TDoA-2 to TDoA-3 so the anchors would not interfere with each other. We ended up using 12 anchors in total which gave enough precision for the PolyHackers to complete their challenge.

The PolyHack was a success and we had a great time. The winning team in our challenge, Electek Innovation, managed to deliver 19 parcels during the 5min with the use of a “loop” system. Congrats and well done! If you get inspired by this hackaton the CrazyServ is available on github! Together with a e.g. swarm bundle it shouldn’t be to hard to reproduce.

Thanks Telejob for letting us take part of this great event!

 

Ever since the Raspberry-pi zero was released we wanted to find-out what it would take to fly one with the Crazyflie 2.0. One immediate issue is the size and weight of the R-Pi-Zero. It is just a bit to big and heavy to make it work without modifying the Crazyflie 2.0. Also it requires 5V power which is something the Crazyflie 2.0 doesn’t provide if USB isn’t connected. Actually the R-Pi-Zero works well down to ~3.6V but this is still too high to reliably run directly from a single LiPo cell. So to begin with we created a Raspberry Pi Zero power deck. It is reusing the same step-up/step-down (STBB1) as used on the LED-ring to make things simple and the output is set to 3.8V. Other than that the UART and the I2C interfaced has been connected so that the raspberry pi zero could control the Crazyflie.

The raspberry pi zero would then be soldered to the deck with 0.1″ header pins. The result can be seen below and the power part works well. We chose to solder the deck header pins to the deck, instead of using the female deck connectors, to make it more sturdy. Another thing we did was fitting a Pi-camera using a 3D printed mounting bracket we designed. We think this is one of the interesting use cases, to run computer vision or maybe neural networks :-).

Well unfortunately this only solves the first part, powering the R-Pi-Zero from the Crazyflie 2.0. Next step will be to modify the Crazyflie 2.0 with bigger motors/props so that is can carry it for a decent time. So story to be continued…