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46  Using Arduino / Project Guidance / Re: Am I overpaying for this? on: October 06, 2012, 02:42:08 pm
If you want to do mostly robotics and you have a $76 budget, I would recommend that you shop around on e-bay and buy JUST what you need. The kit you linked to is for general use and has a lot of stuff you may not want or need for robotics. Even if you did want all of it, you could probably do better buying individual items. Did you read the reviews? They are a little mixed, but generally good... but once again, theses are reviews for a generic kit and if your interests are more on the electronics side than the robotics, then it might be worth it.
47  Community / Exhibition / Gallery / Re: My first amateur level project on: October 06, 2012, 02:02:37 pm
 That is a very ambitions first project. You have a lot of cool stuff going on. Congratulations. It  sounds like you put it together pretty quickly also.
48  Topics / Robotics / Re: Homemade biped robot on: October 03, 2012, 09:48:30 pm
 The EZ-Robot kit web site advertizes a Heavy Duty Servo... you might try that. I'm not sure what servos are used in the kit.
49  Using Arduino / Displays / Re: No problem, just a question (LCD: 4 bit v. 8 bit) on: October 02, 2012, 01:36:56 pm
So any speed gain going from 8-bit to 4-bit makes no practical gain for human eyes.

Makes sense... but why would virtually all display manufacturers waste so much effort to implement something that has so little payoff?
50  Using Arduino / Installation & Troubleshooting / Re: Arduino busted. Want to help a lost soul to understand what part of it broke? on: September 29, 2012, 07:05:11 pm
Did you unplug the shield and try just the Arduino. If so then the next thing to do is buy another atmega chip with boot loader and replace the one you probably fried.
51  Using Arduino / Project Guidance / Re: General series circuit question (noob) on: September 24, 2012, 05:33:08 pm
You can't do that. The buzzer robs too much current ( amps) from a LED in series. You will probably have to wire them in parallel and use an external voltage source... if you are not already doing that.

It is not good to hook anything up between the pins and ground without a resistor of some kind.  For an LED probably around 300 ohms is OK. for the buzzer it's hard to say. It might not buzz if you have a resistance in series. The pins might burn out if you push more than 40 or 50 mil-amps through them.

If you are going to do much more than just blink LED's, then you need to learn a little bit of electronics.

Google "Ohms law"  for a start. Also you probably need to buy at least a cheap multimeter to know what is going on in your circuits.
52  Using Arduino / Project Guidance / Re: Auto Titration Gizmo advice on: September 22, 2012, 08:20:30 pm
I assume your electrode is a dual electrode that includes both a glass and reference junction.

Practical Makers shield appears to be an amplifier for pH signals. It doesn't give much info on what the output range is but I guess you can adjust it for a 5 volt full range. I tried to look at the PDF file they had but the link was empty... not a good sign.

Developing a instrument amplifier from scratch, is not something you want to do. If you can confirm that the shield will give you a 5 volt output in the pH range you are looking for, I would advise you to use it and get on with the chemistry rather than spending lots of time on the electronics.
53  Using Arduino / Project Guidance / Re: CAN/CANopen on: September 22, 2012, 07:55:52 pm
oric_dan(333) is correct. If these devices are not "patient connected" you will have far less safety requirements than if they are. In either case you will have to probably deal with testing agencies ( which are expensive ) before you can produce a product for use in a medical facility.

54  Community / Bar Sport / Re: Extremes of ridiculous packaging on: September 18, 2012, 08:19:12 pm
Yeah, I got 10 ATMEGA chips from Mouser in a box almost big enough to put a lap top in... Shipping was paid by the receiver. I also got a couple of Chinese shields packed in an envelope with a wrap of bubble pack with half the pins bent over... Shipping paid by the sender. Oh well...
55  Using Arduino / Installation & Troubleshooting / Re: Strange uploading problem on: September 18, 2012, 01:45:23 pm
I had a similar problem but it was with an Arduino clone. Some how the uart was not recognized in the 1.0 IDE, but the skripts could be downloaded using an earlier rev or the chips  interchnged with one that had a downloaded sketch with no problem.

If you have two authentic Duemillanove purchased at the same time, this sounds unlikely, but It might be worth a try loading a pre-1.0 rev and trying it.
56  Using Arduino / Sensors / Re: K type thermocouple on: September 17, 2012, 02:58:27 pm
The older MAX6674 and MAX6675 both work with K types, they work at 5V, and there is working arduino libraries (at least, there's a library for one that can be modified for the other).

I think someone even has a shield available.

I have not seen one ,  but you can buy adapters to 8 Pin SOIC to DIP8 Adapters. They are a pain to solder, but they do work.
57  Using Arduino / Sensors / Re: A to D converter onboard on: September 17, 2012, 02:48:11 pm
I sort of underatnd that but i thought the digital pins on the arduino could only read high or low. I could put a A to D converter before the arduino but does it still have to communicate through the analogue ports. I dont understand how the digital pins can read 2 bytes.

If you already have an A/D converter, you do not hook it up to the analog pins. It will already have converted the analog signal to a digital output. the output come into the Arduino through a digital pin one bit at a time. That means basically, that if it is a 12 bit A/D then you send out a pulse (clock signal) from another pin on the Arduino 12 times to read all of the 12 bits in. There are lots of scripts that show how to do this. You need to know the sequence of clock pulses that are needed to obtain the total reading sent from the A/D. If you are a complete novice programmer, developing your own script may be pretty frustrating. If the chip you are using already has a script or library written for it, then the task becomes much easier.
58  Using Arduino / Sensors / Re: Buying Sensors/Reading Sensors on: September 17, 2012, 02:36:46 pm
$85 seems high for what is included in the kit. You should be able to get the components for far less than that, and with so much free documentation on the web, the info that is included is not a big deal, but it looks like it would get you up and running, at least there is documentation for the projects you can build with it.
59  Community / Exhibition / Gallery / Re: Warning! One Million Ohms on: September 17, 2012, 02:30:34 pm
Maybe you could just have a couple of  ultra-brite diodes blinking and just say WARNING INFA-VIOLET RADIATION! or WARNING ULTRA-RED RADIATION!
60  Using Arduino / Sensors / Re: Buying Sensors/Reading Sensors on: September 13, 2012, 08:11:59 pm
It's a good price for that many sensors. But there is no documentation how to use them. If you are wanting to try out a bunch of stuff, then this sounds good. If you just want to try out out the Arduino, and not sure if you can handle the code or electronics, then maybe you should just pick out something easy first, like maybe a stepper motor shield or just a few LED's.

I think offers like this will be around for a while.
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