I wrote most of this post in an email to one of of members who couldn't make it to the meeting this week. It seemed appropriate to post it as a news item so people can get an idea of what we've been talking about.

The discussions this week were quite technical, some of which were well over my head. While we didn't managed to provide any solid solutions to the all the problems presented. I'm hoping that we can turn the Maker Meet ups into problem solving sessions for all kinds of problems facing Canberra makers from the experienced to the novice. If you have a problem, no mater how trivial or complex, I'd encourage you to come along to our next Maker Meetup in a fortnight (there will be an update here to remind you) and present it to the group. We might not be able to solve it right away, but we might be able to give you some stimulating ideas that help you get you project moving again.

Click on to see what we've been up to.

We spent a lot of time talking about Paul's EV Bike conversion project. He was keen to get some feedback an some LiFePO4 battery management system (BMS) schematics he spotted on the Internet. For the most part we couldn't actually work out what was going on in the schematics as they had been put together by a committee of forum users where some of the design decisions came down to "I had those parts on hand so I used them". The three forum threads, multiple youtube videos, a couple of schematics and photos provide plenty of information just not in an easily digestible format. Discussions on this problem have migrated to IRC.

Geoff has been doing some work in gEDA to get a feel for how it can be used out side of his work were he has access to Altium. One problem he has with the current suite is the lack of a footprint editor. He's been working on a python based tool that can display a GUI editor and a text editor that are both updated in real time. At the meeting Geoff showed off a short python script which does two way communication with a gvim editor window. It doesn't do anything terribly interesting just yet but was one of the roadblocks he had to navigate before he could progress the project.

We also had the compulsory LED matrix discussions. Alastair showed a PCB he's building in Eagle Express with a bunch of shift registers and current limiting resistors. He's going to isolation route the PCB on his CNC mill and mount it as a backpack on an 8x8 - 5mm - RGB LED matrix he bought recently. He also showed off the byte-buffer clocked-serial shift-out AVR code he's been optimising for pushing data out to these displays as fast as the AVR will net him without writing the ASM himself. We then went on talk about how it should be possible to write AVR code to do per pixel software PWM for the HT1632 matrix displays if we can blat out the data fast enough.

I showed some progress on Emiglio's head rotation joint. I have started the mounting plates that sit inside the collars in the body and the head. I'm still waiting on the Lazy Susan bearing I ordered off ebay to show up. Once that's in I can decide how I'm going to go ahead with the locomotion system. Some of the suggestions so far are:

• setup a ring of coils on one plate and magnets on the other and build a BDC/Stepper motor (Alastair);
• use a friction wheel on a stepper/gear-motor/continuous-rotation-servo (Angus & I);
• for some thing simple, I am thinking about just using a regular hobby servo and some push rods;
• I also thought I could cut a ring gear profile in one of the mounting plates and cut a gear to mount on a motor; or
• buy a ring gear & matching gear and use those instead (Angus).

Once I have the bearing I'll have a much better idea of what will fit.
We also talked a bit about what we could do to transfer power and data between the body and the head if we decide to go with a solution that allows >360degree rotations. The options so far are:

• don't bother, it'd be cool but not really that important;
• a commercial slip ring;
• a DIY slip ring;
• a PCB with ring traces for one side and brushes on the other; or
• just including enough slack in the cables that we can do a few turns without tying ourselves up and just remembering if he needs to unwind.

That's were we are at; lots of interesting projects in the works and plenty of stimulating discussions going on. Next week the committee will be meeting to discuss what we need to be doing in the background to organise the events and projects we want to run as a group. Everyone is welcome to come along to the committee meetings and provide input on the direction of Make, Hack Void, but we ask that you don't bring projects along until the Maker Meetup which will happen the week after.