Good point.
The nice part is, switching that around necessitates the interchange of only four brackets.
So, for an extra $20, I suppose I’ll just get them ahead of time and have multiple options.
To be honest, I had been thinking of changing my biped to the above sort of setup, as it seemed to be a lot more effective when I was playing around with the Biped Scout.
I’ve been lax and haven’t renewed my subscription to Servo.
:X
Thanks for reminding me!
You’re being lax again, this time with your reading. 
I said Robot magazine, not Servo.
Cheers, Harry
Lol!
Woopsies.
Well, I need to renew that, too.
:X
And I should probably subscribe to Nutz and Volts while I’m at it.
I’ve had a ball with the BRAT. It’s really amazing what can be done with just 6 DOF. I think a natural progression would be to add 2 more DOF to see what can be done then. I think it would open up another completely different set of possibilities. Actually, I’d guess that the 8 DOF configuration would provide the best platform for your foot sensor experiments. Then again, simpler still would be a hip servo and 2 ankle servos and may work just as well for your project. Hmmmm…
I wonder if Jim has any thoughts on this?
Cheers, Harry
I’ve no doubt that I’ll eventually learn more from the full humanoid about balancing than I can ever learn with this little bugger.
But, the sheer volume and variety of what I’d need to understand is a bit daunting.
This little guy should get me kickstarted in the right direction.
Worst comes to worst, it doesn’t.
In that case, I’ll just have to part this poor bugger out and have two extra pan and tilts.
Yeah, start with a BRAT. 
Then add more DOF’s as you work. Think of all the other BRAT builders who will be praising your name Nick. hehehe
The switch / foot PC board is a good idea. I want to have a PC board made with the switches and even LEDs, that can either replace the aluminum foot for lightweight bots, or be added to the aluminum foot for heavier bots. It’s on the drawing board anyway. 
whats wrong with micro servos?
Better add a place in the bottom of each foot to hold a couple of 2 cell LiPOs that can be joined in parallel and regulated for servo power.
That’s my story and I’m sticking to it, Harry
I’ve been thinking about this quite a bit and I think it’s the way to go for me to start looking at balance in humanoids. The configuration that seems to make the most sense to me is to add another servo just above the foot with the same SES components that are on the similarly placed servo on the BRAT. This would require an ABS-04, ABS-06 and ABS-09. Jim, what do you think? I remember you suggesting that adding another DOF at the hip may make more sense.
Any thoughts from other BRAT owners or SES experts?
This looks really interesting too. Any chance that it’s moved off the drawing board yet? 
Thanks, Harry
No sorry, I have my PCB engineer working on our new Dual H-Bridge, and he will not be able to work on other things untill it’s completed.
Pleeeeeeeeeeeeeeeeease tell me that it will be at least 5A!!!
It must be! (and cheap, please!)
theChipmunk
Heh heh, I just got my first issues of Robot, SERVO, and Nuts and Volts this week. I am in information heaven right now!
Wow, I know just how you feel. This should keep you bussy in the bathroom for hours.
It’s 10 amp, two channels. It will be like the SSC-32… Feature packed but inexpensive.
Oooh.
That sounds very useable, Jim.
How inexpensive!? If it was a good price, I would hold fire on buying the Polulu.
BTW, do you ship to N Ireland for free…?
theChipmunk
It’s way early to quote a price. I probably should have kept my mouth shut. 
Unless UPS starts delivering my packages for free, I’m gonna have to keep charging for the service. Sorry…
Nope. We appreciate the fact that you can talk to the Head Honcho…
theChipmunk
cough Thread hijackers. cough
I finished the schematic for this bugger, today:
img1.putfile.com/thumb/9/24517202050.jpg
Hopefully, my idea of using LEDs to visually confirm that the buttons are depressed will work.
I tried it on a breadboard, and it seems fine.
Hopefully, it won’t affect the 20ms button debouncing in the software.
Each LED should be getting around 5mA (5V / 1000 Ohms), so I’ll be wasting 40mA on those LEDs alone, but I feel it’ll be well worth it.
Especially since I’ll have much more than an amp of logic power to burn.
Does it look like I’ve got the seperate batery-source thing correct?
Should I use a common ground as I did above, or should I keep them seperate?
I was going to put a schottky diode to protect for reverse connection in the servo supply as well, but I opted against it.
At 8.4V max, 7.2V nominal, I’m cutting things closer than I’d like.
I’ll be regulating VS to 6V, so if I assume a .5V drop, there’s little leeway for another small drop with a schottky.
EDIT: Sorry about giving three capacitors the same name (“C2”).
Thus are the limits of copy/paste truly realised.
