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1  Using Arduino / Motors, Mechanics, and Power / Re: how to make brakes for RC car ? on: July 09, 2013, 03:27:07 pm
Nope.  Put 240 on the pot as max, and when the pot hits 240 upwards arduino supplies max power to the motor, but limits the reading to 240, even if its 249.  The brake pot is read as is, so 241 on the brake pot would kill power to DC motors completely.

So, 50 on boths pots = zero power to DC motors.

240 on accelerator, 120 on brake = 50% power to motors (remember 240 = 100% power)

That way anything where brake > accelerator applies power to servo assisted brake.

Nice and simple and involves less components smiley-wink
2  Using Arduino / Motors, Mechanics, and Power / Re: how to make brakes for RC car ? on: July 09, 2013, 01:08:43 pm
And to make sure, just programme the full throttle range to 90% of its sweep, then when arduino sees full throttle, it's only 90% in reality, so when 100% brake is applied, it will ALWAYS be a high value than throttle regardless, thus slamming on the brakes.
3  Using Arduino / Motors, Mechanics, and Power / Re: how to make brakes for RC car ? on: July 09, 2013, 12:46:21 pm
It would help if you could give a picture of the car setup.

Personally I would code the brake to remove throttle up to the point in which the brake is mor than the throttle, then actuated a servo with some form of friction device on the driven axle.  That way limiting the amount of additional components required.

Presume you're using some form of pot for the accelerator and brake... So if throttle is on full, apply half brake arduino supplies half throttle, simple really.  If throttle is on half, apply full brake, servo actuated to ram on the friction. Simple really.
4  Using Arduino / Motors, Mechanics, and Power / Re: Does 7.2VDC RC battery pack kill 6VDC servos? on: January 11, 2013, 07:42:36 am
Get a BEC for off the shelf voltage conversion, they're pennies
5  Using Arduino / Motors, Mechanics, and Power / Re: relay to control 18v DC drill on: January 02, 2013, 09:15:45 am
You could use a brushed motor ESC and effectively replace the whole control circuit for the drill.  The power connector connects to your battery, the signal (white) ONLY to arduino and the output to the drills power drive.  Gets rid of the whole power activation circuit.

http://www.hobbyking.com/hobbyking/store/uh_power_Search.asp?strSearch=Brushed+esc

It works with standard remote control output signals, easily replicated with arduino.
Just a thought. smiley
6  Using Arduino / Motors, Mechanics, and Power / Re: Can a Pi be powered from the 5v pin ? on: January 02, 2013, 09:09:24 am
A very cost effective method for powering a pi is using a UBEC

http://www.hobbyking.com/hobbyking/store/__14310__HobbyKing_UBEC_3A_2_6s_LiPO.html#relprodspan_focus

You can select 5 or 6 volt output up to 3amp draw, so perfect for a pi.
It'll draw power from 2S (7.4 volts) up to 6S (22.2 volts) DC source, so perfect for most hobby style LiPo batteries.  You will need to solder some terminals and possibly reconfigure the it put, the white wire is. Signal wire, btw, so you won't need that.  You can either just chop it out or ignore it.
7  Topics / Robotics / Re: Homemade biped robot on: October 07, 2012, 12:49:33 pm
http://www.servocity.com/

Those guys are pretty switched on, and will ave anything you might need.
8  Topics / Robotics / Re: Video Camera on: October 02, 2012, 10:38:49 am
You're right, there's more reflected wave forms on the deck.  More of a reason to use circular polarised antennae ;-)

So far as staying in shape is concerned, there's only really one chance for it to get bashed in a flight unless you're doing it wrong, lol.

Personally I'd go for a virivent, they "apparently" perform better than a Clover and have a flatter profile.
9  Topics / Robotics / Re: Video Camera on: October 01, 2012, 04:14:51 pm
Two particularly good articles on here for antenna creation

It's often a bit more than just range you need to consider.  A cloverleaf with a high gain patch will also cut out cross polarity interference, something you especially need to consider with a moving object.
10  Topics / Robotics / Re: Video Camera on: September 28, 2012, 06:28:16 pm
Sounds like you might want to investigate skew planar / virivent antenna for your transmission issues.
11  Topics / Robotics / Re: Robot From An Existing Toy on: September 27, 2012, 06:59:28 am
Big trak?
12  Using Arduino / Displays / Re: Largest Useable OLED Screen? on: May 10, 2011, 05:38:25 pm
Why OLED? Is this indoors?  Outdoors?  Under what lighting conditions?

Variable light conditions from full sun to night time, plus OLED more for viewing angle.
I'd considered 7 segment display, the reality is though that it's fixed, dependant on how many segments it has.  The other reality is colour scheme.  It doesn't really lend itself to high contrast black on white for day time use, then night friendly colours - which obviously can be achieved with an LCD / OLED, although LCD has the back light on continuously.

And Liudr, yep, that is also the plan, which ever screen I use, I'll be doing that anyways... for whatever key point of information is in the spotlight at that time (I'm thinking ahead - forgive me)
13  Using Arduino / Displays / Re: Largest Useable OLED Screen? on: May 09, 2011, 05:44:16 am
3.2" might work... any others?

5" would be better smiley
14  Using Arduino / Displays / Largest Useable OLED Screen? on: May 09, 2011, 04:21:40 am
So I'm working on a project that needs a screen to be clearly visible from at least 4 meters (12 ft) away.

The output will be 2 digit numerical with supplementary information being available underneath, the supplementary stuff is not vital to be seen from a distance.

So what's the largest OLED screen available wihtout the price being overly silly?

I'll be using it with a Mega, if that helps for pin assignment smiley

And yes, I've googled til I'm pink behind the ears, but just not getting any joy.
15  Forum 2005-2010 (read only) / Troubleshooting / Re: Help with installing a bootloader on: August 13, 2010, 04:31:57 am
I'll PM you smiley

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