Saturday, October 08, 2005


I took R2 to the Comic/Horrorfest today. I was pleasantly surprised at the battery life for the motors. I got about 3 hours worth of drive time, with pretty heavy use. I did some speed trials out in the open parking lot and he was haulin'. Something happened with the bluetooth connection on the mini though, so I couldn't get the sounds working (should have brought an LCD monitor), but other than that everything went great. People love him, especially kids.

Wednesday, October 05, 2005

Power board problems

When I installed it, something happened to one of the variable voltage supplies on my home-made power board, and now I'm not getting anything from that supply. It's wierd because it worked on the bench, and the device that it was powering (the holoprojector LCD) still works fine when powered from another source. But the board acts like it's blown or shorted on the 6V rail. Hmmm.

Single Channel Vantec Installed

The single-channel Vantec motor controller is installed and the dome control is back online. This controller acts a bit different from the dual channel one in that it pulses the motor on power-up. So that means the dome twists about a 1/4 turn when I throw the battery disconnect switch. No big deal, unless you're not expecting it.

Tuesday, October 04, 2005

Mac mini battery life

I've not done any real power management yet, but so far I am getting about 1 hour of run time for the Mac mini from a fully charged 12V 7AH battery running through the CNX-P1900 DC-DC converter.

I have put 2 of those batteries in parallel now, so hopefully I'll get about double the run time.

I run all the motors and other electronics (dome logics and PSI LEDs, holoprojector LCD, speakers) off of a separate pair of batteries. He has 4 total batteries inside: 2 in the battery boxes and 2 in the lower body.

I plan on using the Phidgets' voltage level sensor as a monitored analog input for power management once I get into the programming end of things.

Update and wiring changes

PCB2 is sold and will ship in the morning. I still have PCB1 up for sale. It has 2 blown channels.

Also, I ordered a set of 4 aluminum ankle details from Jerry, and he is going to ship them Monday with my welded steel center foot and misc. mounting hardware!

I wired up a DPDT switch to control the shoulder motors so I can do a manual 2-3-2 for now.

I'm still working on the power board. The adjustable regulators are not behaving like the schematic says they should, so I need to figure out what's going on. UPDATE: The power board is done and works perfectly. I now have +5V for the RC receiver, +6V for the holoprojector LCD, and +7.5V for the stereo amplifier.

Monday, October 03, 2005

PCB1 Blown (again)

Last weekend my PCB1 blew another channel (the second time this has happened with no apparent cause.) So I have removed it and will replace it with a single-channel Vantec (which I just ordered) for the dome rotation control. I am also building my own power supply board with 2 variable voltage supplies plus 5V and 12V regulators. I have put PCB1 and PCB2 up for sale in the builders group. No need for PCB2 now that I am using the Mac mini and the Phidgets boards.