This week and the next we will be visiting Seeedstudio for the first time so tonight we have been finalizing the travel plans! That might sound easy but it’s been a bit like solving a puzzle since we have to take vacation from our day jobs to go, and each one of us has slightly different vacations.

The purpose of the visit is to get a chance to finally meet everyone that we have been talking/mailing with during the last 18 months and also helping out during the final testing stage. And of course it will be really great to visit Shenzhen and fill our luggage with electronics for our trip back :-)

As for the production it’s still progressing according to schedule, we will post actual photos of the boards as soon as we see them :-D.

Even though controlling the  Crazyflie with a PC is quite unique and permits a lot interesting things to be done, like controlling Crazyflie with a webcam or getting realtime telemetry, we have also been looking at controlling it with a, pc-free, standalone controller.

Current (unfinished) implementation of a standalone controller are using Crazyradio as a PPM to CRTP converter, a very experimental Android app, and using a raspberry pie as ground station. This week we finally managed to fly Crazyflie with an E-Sky transmitter:

The transmitter is using a nordic-semiconductor chip compatible with our radio. The protocol is also well documented by dvdouden et al. It is using a power amplifier and uses a channel hopping scheme which makes the radio link quite secure.

Code to support this has been in the repo for a couple of week but a problem was that, by default, this transmitter was mixing pitch, roll and thrust channels which made the control of our Crazyflie nearly impossible (pitch and roll was changing by increasing the thrust ….). This week-end, we discovered two switches in the battery compartment, with which you can disable the mixing, and by doing that suddenly the Crazyflie is flying! There are still some work left to make RC transmitters works as good as a gamepad but the current source code is good enough to fly. Overall we have observed that a gamepad is really ideal to fly the Crazyflie in a fast and dynamic way. By comparison RC transmitter benefit by having more precision, mostly for the altitude control, but we are not used to it and it does not feel that ‘fast’ (our opinion).

As for the pre-order production, it is still going forward as planed. Testing of the first production samples  are finalized and now all the PCBs has been manufactured. The expected time of shipping is still according to the Seeedstudio Crazyflie product page.

We just received the first 10 sample boards from the production at Seeedstudio :-D

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So far we got time to test only two boards and they are working. We have finalized the firmware, bootloader and production scripts so now it has really started :-)

Nothing new exiting about the production, it is still going as planned :-). Meanwhile we are focusing on stabilizing the Crazyflie firmware and its side projects.

This weekend we fixed a bug related to the memory allocation, which we have had a while now and that we never had time to track down. It kind of forced us to use heavier machinery so we decided to setup eclipse for debugging FreeRTOS threads and it happened to be very useful.

Since version 0.5 OpenOCD contains a rtos-awarness mode for FreeRTOS and, when painfully configured in eclipse, this allows us to observe the stack trace and the running state of all the tasks running on Crazyflie:

This helped us to track-down the bug much quicker and will greatly help us in the future. We also found a eclipse plugin, embsysregview, that enables one to show and analyse the peripheral register values, great little plugin!

The virtual machine will be updated with the debug environment and we will try to update the Wiki with the setup procedure.

As announced on the last Monday post and as well discussed on the forum, one of the things we are working on right now is to create a virtual machine (VM) that would greatly reduce the haste of getting the running/development environment up and running. The VM will be a Linux system that can run on Windows, Linux or Mac and that will be pre-configured to work with Crazyradio and Crazyflie. We are going to post the first alpha of this virtual machine during the week using Bittorrent so if you are interested to test it stay tuned to the forum!

As for the production of the Crazyflie’s things are running according to schedule, so far so good!

Also from the VM discussion we discovered that Mike has done a great job getting the Crazyflie client to work on Mac OSX. This is going to greatly help supporting Crazyflie on OSX.

Who knew that it was possible to discuss product descriptions for almost a whole evening… Since the release is getting really close now we actually have finalize the product description and it turns out that we didn’t all agree on everything. One thing that’s good about being three people in this project is that we can have a lot of discussions that gives (hopefully) good results and the bad thing is that there’s a lot of discussions which takes a lot of time :-)

Another night without any flying at all, just administrative stuff… But if everything is goes according to plan the pre-order should start within the two next weeks!