Building the MegaMini

On Sunday the canterbury aerospace club populated the first of 2 PCB's for the battle blimps competition.  Hanna took some great photos and video of the build day.

It went reasonably well and we got the maple bootloader onto a few of the boards.  Next week we will run the second half of the workshop where we build the battle blimps shield which we will be using for communications and motor driving on the blimps.   We will also finish up the few boards incomplete megamini boards

It was great fun to use the pick and place machine and looking at solder paste under a microscope is amazing.  It looks like a pile of ball bearings, I strongly suggest you try it some time :)

Quite a number of the group had never even soldered before and I think throwing them in the deep end and starting with surface mount has been quite good.  There seems to be a perception that surface mount is really hard when actually it isn't that bad. 

Battle Blimp Boards, PCBs

The PCBs for the battle blimps boards have finally arrived.  We got them on the Dorkbot PCB group order and they have taken ages to arrive.  I think they got lost in the postal system as the PCBs from dorkbot have always arrived much faster than this.

The battle blimp boards are based on the Leaflabs Maple.  The PCBs on the left are the microboards with the ARM cortex chip, the ones ont he right are the motor/radio shield.  In all we got 18 PCB's of each made up.

We will have one spare which we can use to test the current handling of the motor driver chips and the high power Fets.   As the traces are only 1ounce per square inch they won't handle that much current before exploding so we will investigate roughly what that point is.  We have a work around for people who want to sink heaps of current with the fets.

I'll order the parts from Digikey this evening and then we will run the SMT assembly workshops once they arrive :)

Battle Blimp PCB

One of the projects I'm involved in running is the University of Canterbury Aerospace Club.  Our big event this year is Battle Blimps :)

The plan is for people to battle their blimps until the other blimp is no longer capable of flight.  The simple version of the rules is as follows:

100 gram weight limit. (including envelope)
No flame weapons.
No untethered projectile weapons (Unless you are prepared to demo its safety int he usual fashion)
No intentional jamming of opponents controls.

Other than that people can do what they like.   I designed a pair of battle blimp boards, a micro board and a battle blimps motor board.  The micro board is based strongly off the tested mini rocket flight computer board (http://andre.team9.99.org.nz/2011/07/microprize-flight-microaltimeter.html) but with better separation between the analog and digital sections.   The motor/high power board is a pair of TB6612FNG dual H bridges and 4 30 amp NFets as low side switches.  It also has a RMF12B transceiver with a  library based on the JeeLabs JeeNode code: http://jeelabs.net/projects/hardware/wiki/JeeNode

Obviously the traces will horribly explode if someone tries to draw 30 amps though the board but we have a work around for that.  Not that I can think of a battle blimps need for 30amps but people can then use the boards to drive little robots etc.

The design will be licenced as open hardware.

The Microcontroller board with ARM cortex M3

The Battle Blimps high power/motor shield with the RMF12B transceiver