Loki - Gets A"Head"

GroG's picture

Description: 

loki_head.jpg

 Loki's Head

 

control_page.jpg

 

Loki's control interface

 

Loki_color.jpg

 

 

Loki grew a head recently in order to support some experiments with stereo vision.  The two lasers are for other tests :)

 

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fritsl's picture

I would like you to sit on

I would like you to sit on it, and then I could remote you around! :D

/ Fritsl

GroG's picture

This could be arranged ......

the control page will be up soon :)
jip's picture

Regarding powering this thing...

Hey grog!

This is an awesome project and it was fun to read about how the robot crashed into your cabinet and all :-). I'm particular interested in the way you're powering the robot since I would like to do that whole mini-itx thing myself. After reading about the picoPSU it seemed that it needs 12 volts regulated? Do you just connect the battery directly or do you have some voltage regulation between picoPSU and the battery?

- Jimmy

GroG's picture

Regarding powering this thing...

Regarding powering this thing...


Thanks!
I specialize in failures - you're garanteed to learn something from it.

The pico is working great for me so far.

Since all the car manufacturers want to put computers in cars now, it has become very simple. The pico PSU 120 hooks directly to a 12 volt battery. So 12 volts on one side, then you plug that little gizmo directly into an standard ATX connector on a motherboard! Very nice!

I have found that when the battery drops below 11 volts, the pico will cut power completely (probably a good thing - when you underpower things - they typically start get HOT).
I re-routed the motherboard fan and disk power to go directly to a battery, i figgured this would be more efficient (even though pico runs @95% efficiency)

Here's a link to the specs http://resources.mini-box.com/online/PWR-PICOPSU-120/PWR-PICOPSU-120-man.... You don't need to regulated it - You can put some caps on to filter out the noise if your powersource is the same as your motors powersource. I initially had my electronics battery and the wheelchairs batteries seperated, (the best way to filter out noise), however, i now have the electronics battery connected with the wheelchair battery - I'm doing this in order for the whole system to recharge easily.. The wheelchair comes with its own battery recharger on board - now i just got to teach the bot to find the 120v outlet when its feeling low.

Hope this helps Jimmy,
cheers,
GroG





jip's picture

Thanks for elaborating it

Thanks for elaborating it sounds pretty straight forward!

How long does the robot run before the battery drops below 12V? I don't really know anything about the curve of discharge for typical car batteries... do they hold close to 12V for almost all of their life and then rapidly drop to very low voltage or is there still a lot of juice left in them at a lower voltage level?

Those picoPSU thingies sure seem like the way to go when going for the whole robot-using-atx-mainboard setup, thanks for the info!

- Jimmy

TheCowGod's picture

Ditto, thanks for the info,

Ditto, thanks for the info, that's something I'd always been interested in playing with too (powering computers from a car battery). I had some brief forays into 'carputers' for MP3 purposes back in the late 90s, but I was always using an inverter and the computer's stock AC/DC power supply, and I'm sure that was really inefficient. This always sounded like a better way to go.

I also find it interesting to read about your work with those bigger motors, because that's something else I want to try sometime -- building something bigger, something that can drive around outdoors in the grass and stuff. It's interesting to hear about needing to use PWM just to get those larger motors going.

Dan

jip's picture

When building something

When building something bigger remember it can hit you a lot harder if you make a programming error :-D. I don't want to read the headline "Big Drum Machine beats the living daylights out of creator" :-)

- Jimmy

TheCowGod's picture

Haha, I'll be careful. I'll

Haha, I'll be careful. I'll only give it Nerf bats and rolled-up newspapers until the code is well tested :)
fritsl's picture

Never..NEVER give weapons to

Never..NEVER give weapons to robots!

(I am just saying it, better safe than armageddon) 

/ Fritsl

GroG's picture

Apparently, not everyone

Apparently, not everyone believes this...

But I have to admit, I really like SRL

 

Power Log

I don't know all the details of my setup regarding power decay, and longevity of life for loki, but I've will continue to update a table from experiments http://www.gizmogarden.com/index.php/Loki_Off_The_Shelf_Advanced_Robotic... with the cpu fan directly hooked to the motherboard and the recharger plugged in, I found that my bot was loosing life force... I want to keep it online most of the time so I (please forgive me) CUT the CPU fan ! I would not recommend this to anyone - I know from previous experience (heh) that some cpu's have motherboards & cpus have overheat protection, but someone in their right mind probably would not want to risk it. The recharger is a trickle recharger, so after the fan was cut the charge started to climb back up. I'm back up to 12.1 v, but the recharger is still going nearly full tilt @ 3.75 amps. I started running some motion detection programs on the board and got it to heat up to 56 C. I'll keep you posted, You'll hear me cry, if I fry my CPU :P
TheCowGod's picture

I've had computers where the

I've had computers where the CPU fan died, and all that would happen when it overheated was the computer would freeze solid and I'd have to do a hard reboot. Never hurt the hardware. But maybe I just happened to have a machine with the built-in protection :) Good luck with yours.

Dan 

GroG's picture

They had a streaming video

They had a streaming video at the end but now you have to download it

(not pretty - AMD goes up in smoke) - as wise man once said to me, "Once the magic smoke has left the chip, it is very difficult to get it back in"

http://www6.tomshardware.com/2001/09/17/hot_spot/

fritsl's picture

Lol,Someone said to me

Lol,

Someone said to me "Current is smoke within the cables, where it should be.". "You can tell you have a leaking problem if some of it is getting out." 

/ Fritsl

ifreq's picture

Woah GroG, your project

5

Woah GroG, your project seems too very very nice :-) Tho its like giant compared to my tiny bug. Thanks for the picoPSU info, just the one I needed to continue :-)

 

 

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