We just finished the top level BOM, test plan, fabrication files, etc… which mean everything required to order the pre-series of the Crazyflie. The pre-series is meant to be last version before the first real production batch and the idea of it is so that we can test the manufacturing and verify that it is manufactured with good quality.
One of the last minute changes we made for the pre-series has been to power the motors directly from the battery instead of through the power management chip. This should gives us up to 8% more power and efficiency due to power management mosfet on-resistance losses. It should also reducing the voltage drop which causes disturbances to the other circuits. The only drawback is that the Crazyflie consume a bit more power when OFF, because of the leakage current through the motor mosfets, but it is still within acceptable limits (a full battery will still take more than 2 years to be depleted by our electronics). Also the battery can now be swapped/disconnected for storage as we have added a connector.
Our target is to have the Crazyflie DIY kit availible for X-mas. It is very tight and it will be hard but what would life be without challenges :-)