arduino shield, potentiometers

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danmcquillan
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arduino shield, potentiometers

Postby danmcquillan » Mon Jun 02, 2014 11:47 pm

i bought a MeArm kit at the science museum, after building the claw (the Claw!) with my son.
i already have an arduino uno but i'm still new to this making stuff. can you tell me what other bits of kit you were using for the 'control' side and how they are used - i remember a shielfor connecting to the MeArm (& power supply?) and some button-like potentiometers.
cheers
dan

GastonLagaffe
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Re: arduino shield, potentiometers

Postby GastonLagaffe » Tue Jun 03, 2014 2:46 pm

Salut Dan,
the servos need to be connected to pins capable of PWM (pulse width modulation). The Uno has 6 to chose from: 3,5,6,9,10,11 and the sample code uses 11,10,9,6. The potentiometers should be at least 10kOhm with the middle pin connected to one of the analog input pins A0,A1, A2 and A3 and the end pins connected to GND and +5V.
The arduino needs to be powered through an external power supply. The servos draw a lot of current when moving the mass of the arm and the standard USB port of a PC will not provide enough power. The result is a constantly booting arduino and a meArm that goes nuts.
The two servos that lift the arm have a relationship that the extending arm may not fall behind the lifting arm. I am working on the arduino code to drive the arm from the connected PC to save the potis that will take this relationship into account.

Ciao, Mathias

phenoptix
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Re: arduino shield, potentiometers

Postby phenoptix » Wed Jun 11, 2014 3:43 pm

The basic shield I use uses a pack of these and one of these together like this
Image

RorschachUK
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Re: arduino shield, potentiometers

Postby RorschachUK » Thu Jun 12, 2014 9:34 am

Have you considered stocking the little analogue thumbstick breakout boards? Two thumbsticks make for a much more intuitive experience than four potentiometers IMO - and the WiiChuck plus a cheap Wii Classic controller clone is better still, would be dirt cheap at Shenzen prices. Add a Nokia 5110 LCD and you've got a kit for the Movement Recorder sketch, which is also handy for finding out and writing down coordinates when trying to hard-code a movement sequence.

phenoptix
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Re: arduino shield, potentiometers

Postby phenoptix » Fri Jun 13, 2014 5:05 pm

I have a bunch of them in stock awaiting the camera treatment! Will look into those other bits too. Cheers as ever Bob!

danmcquillan
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Re: arduino shield, potentiometers

Postby danmcquillan » Tue Jun 24, 2014 1:58 pm

Thanks for the tips guys. I've purchased the board and pots, looking forward to getting the mearm up & running.

judas79
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Re: arduino shield, potentiometers

Postby judas79 » Thu Nov 27, 2014 7:06 am

GastonLagaffe wroteColonSalut Dan,
the servos need to be connected to pins capable of PWM (pulse width modulation). The Uno has 6 to chose from: 3,5,6,9,10,11 and the sample code uses 11,10,9,6. The potentiometers should be at least 10kOhm with the middle pin connected to one of the analog input pins A0,A1, A2 and A3 and the end pins connected to GND and +5V.
The arduino needs to be powered through an external power supply. The servos draw a lot of current when moving the mass of the arm and the standard USB port of a PC will not provide enough power. The result is a constantly booting arduino and a meArm that goes nuts.
The two servos that lift the arm have a relationship that the extending arm may not fall behind the lifting arm. I am working on the arduino code to drive the arm from the connected PC to save the potis that will take this relationship into account.

Ciao, Mathias

Hello, I'm rather new to this but have done some Arduino programming in the past. That said I've been trying all day to get my MeArm to work with a Wii controller using an adapter, I bought to breakout the Wii. All I have gotten is twitching in all directions as if it is resetting as your post states. I'm using a USB battery power pack 5v 2.1 Amps, but am also feeding the power through my FTDI programmer that is acting as an adapter to relay the power from the battery to the program pins of the Mini Pro.
Do you think the 2.1 Amps is enough power?
Also, the Wii doesn't seem to do anything, not even light up, if it does in fact light up....Never owned a Wii; I bought the controller for this project. Is there a proramming tutorial using the pro mini with a wii and breakout adapter? When I was uploading the code I had to add "#include <i2cmaster.h>" to the code to get it to compile.

judas79
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Re: arduino shield, potentiometers

Postby judas79 » Thu Nov 27, 2014 7:13 am

This is the meArm Wii code with the added "#include <i2cmaster.h>"......Help!
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