Sloth Robot

erco

Senior Member
I'm sure I'll be the first, whenever I can get around to it.

Yes, please take that as an arrogant challenge and do it yourself and prove me wrong! I love the taste of crow! :)
 

stan74

Senior Member
Nice erco. That's £30 with discount code. Hmmm. srfo4 and 4 sg90 is £15 so £15 for the acrylic.
Safe except the sg90 on my robot for us radar has been changed twice. Don't know why they failed and that's just a srf04 left and right.
Coding would be hard unless there's source..in c++
 

steliosm

Senior Member
Thanks, that's great, steliosm!

I just saw that you are in Athens, what a great city! I ran the marathon there in 1999. I only know one other Greek roboticist, Nikos G. A very smart and enthusiastic teacher, you can find him at https://forums.parallax.com/profile/NikosG

And do you know the guys at Muse Robotics? http://www.muserobotics.com/contact.html
Actually, I don't know any of those guys. I'm more into "connected objects" rather than robots.
Sadly, there used to be a Greek robotics forum (grobot.gr) but it's now long gone. I hope now that robotics is a part of the curriculum to actually see this science field to take off in Greece.
 

erco

Senior Member
Lovely, Stanley! Yes, those 12 servos will suck a lot of current. Even more under load! Use good batteries and big fat power wires.
 

stan74

Senior Member
18 servos erco. the pca9685 board don't like not enough power for servos although it has own 5V supply and the servo supply is totally independent.
There's a set all channel command and I use scale..arduino map function but in basic to convert degrees to pulse width. This sets all 18 servos to 90 degrees.....
but with not enough power all servos go to 0 degrees.
My thought is a 8 A bridge rectifier and 7.2V li-ion,4 batterys. The bridge is 2 diodes in series twice so should drop 7.2V to 5V. I've ordered a dc-dc 8A buck converter anyway.
If you nick the init code for these boards they'd work with picaxe.
Also , you can take a wire off the pot in the servo,connect to a-d and get servo position. There's probably a 16 channel a-d i2c chip some where..it seems familiar..I might have some.
I could then teach it to walk. otherwise it's trig or tables.
It needs longer legs so less strain on servos...from first thoughts an tests.
 
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stan74

Senior Member
Yep, a great and worthy experiment. Here's mine, using an 08M2's ADC pin:

That's encourageing. Converting the adc read value back to micro seconds should be easy.
The hardware side of making a walker is...the drill bit snapped and went through my thumb nail...I bought an A8 reprap i3 clone kit for £84 and will print the parts.
 
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