@tronixstuff

looks like a decent book as for as I can tell from the preview. What would be important for me to know before I recommend it to others would be the availability and the cost of the materials you use. You might want to add a section on that to your previews.

just my 2c

by now I have learned that the Leonardo driver issue actually is a feature :-D.

however, its a feature you would preferably not confront beginners with...

on the other hand... I have 20 Leonardo bords. I'd sell them for 12Euro per piece + Shipping :-D

Hi lefty

True, 3.6 is high (and also arbitrarily chosen), however, I think there is no such thing as 'discharging without cell damage'. The impression I get is that its simply a matter of degree.

Discharge it to 2.75 you get 250 to 350 cycles. Discharge to 3.0 you get around 500 cycles.

Every once in a while you will see a battery boast a cycle life of say 10.000 cycles. Usually this will be at 10% discharge.

*

This brings me to another question. Does anybody know if depth of discharge (%) is measured relative to ground or relative to absolute minimum ratings of battery?

EDIT: Thanks CodingBadly for that link. Will be useful.

cool. thanks for your input. I'll be playing around with this in a little while. I'll post what my solution will be.

Links to the datasheets would help me helping you. Also I have no idea what you intend to do.

In general:
Your motors connect to terminals in your motor shield.
Analog sensors connect to Power, Ground and an Analog Input while digital sensors could have multiple ways of connection.
Your servo goes to Power, Ground and a PWM enabled digital pin.

*but*
your sensors might not be compatible with Arduino. They may require external power (if they need more than 5V) or they may require you to setup a voltage divider if they output more than 5V.

Again, you do not give enough information for anyone to help you.

p.

This is a theoretical question, just something I have been wondering:

Lets say I am powering a small device controlled by an ATtiny with a Lithium Ion or Polymer battery. In order to prolong battery cycle life, I want the ATtiny to switch off when the voltage drops below 3.6V.

So in theory I could hook up +V of my LiPo to an anlog input. I then say:

- If the voltage drops below 3.6V, go into power-down Mode
- once in power-down mode the ADC no longer works, so even if I recharge the battery, it will stay in power down mode.
- the interrupts are still checked though, so I could add an external sensor or switch to turn the ATtiny back on.

Alternately I could also go into ADC noise reduction mode and save some energy that way, which would allow the ATtiny to wake up automatically once the battery is charged again.

*

How would you build an ATtiny circuit which tries to extend battery cycle life by limiting depth of discharge?
Is there any way that I can access these functions from within Arduino? Is there any library I might use?

Can anyone recommend me some reading or a link or a tutorial on this topic? Reading the documentation leaves me a bit confused...

Thanks

P.

some googling: http://arduino.cc/forum/index.php/topic,42205.0.html

Hi there

My suggestion: What GrumpyMike says is the easiest solution. Try to understand it (read up on how i2c adresses are set). If you understand it and there is some reason its not possible, then you could get something like this: https://www.sparkfun.com/products/9056

Using the device I just linked you to, you could connect 16 displays with identical addresses to your Arduino.

If you want to do it with only one function, you would need to create a timer object.

something like this

Code:

class timer{
  public: //public otherwise error: test::test private
  int sec; // a variable

  timer(){ //the constructor
  
  }

int run (int x){
sec = x;
// setting coretimer  
unsigned long coretime= millis();
 if(coretime-pscoretime > sec){
   pscoretime  = coretime;
   timestate =! timestate;  
}  
   return timestate;  
}

}; // undocumented semicolon otherwise error:

timer redLED = timer();
timer greenLED = timer();


void setup(){
//set up your leds and millis etc.
}

void loop(){

digitalWrite(1, redLED.run(500));
digitalWrite(2, greenLED.run(300)); // 5 & three are values i put in there at random. no idea what 'sec' should be in your function
}

this is based on what i found in this thread: http://arduino.cc/forum/index.php/topic,42377.0.html
the reasoning makes sense - i have not tested it though

I am still not exactly sure what your question is, what you want help/collaboration on.

I totally understand where you are coming from. There are only so many things you can do with your time and at some point you just need to pick and chose.

Anyway. I would see if these guys http://dallasmakerspace.org/blog/ or these guys https://www.facebook.com/cohabitat have a mailing list and I would post there. One of the problems with the Arduino forum is that its so international, which makes it a bit difficult to collaborate (i.e. I am located in Vienna, Austria) as sometimes its nice to just sit down and have a Beer to get a feel of how the other person 'works', you know?

Btw. Try contacting the forum user NI$HANT http://arduino.cc/forum/index.php?action=profile;u=34047 he is a dude from India who seems very eager to take on projects and who has in the past done work for other people through the forum.

ok, to be more specific:

The battery I wish to charge contact-free will be very similar in specs to this one: http://www.digikey.com/product-detail/en/MEC201-7S/MEC201-7SDKR-ND/2842960

Its very similar to a LiPo, but not completely equivalent (I actually think they are simpler to charge than LiPos)

I am looking for something similar to this: http://www.instructables.com/id/Wireless-Power-1/

I can recreate this, or similar tutorials myself, I want somebody who really understands whats happening and who can help me optimize the process for my application.

Again, this is a paid position - please contact me via e-mail: paul dot strohmeier at gmail dot com

this is a very "doable" project. Everything you need is here. DVDdoug set you up with some good links to start working. I am sure you could find somebody or I also believe you could do it yourself even without prior knowledge (people in this forum are helpful) which of course requires you to be interested in learning this stuff.

I simply am quite loaded with projects I *should* be doing and I just am not motivated to put the amount of work into it if its not something more general. I am happy to assist with coding questions and other issues though.

again - where are you located? Maybe you can find people in a local hackerspace to help out?



*
"doable" as in: many people come here with unrealistic expectations of arduino or of project scope etc. This is *not* the case with your project

Is this something more people than just you might need?

I like this project as its fairly straight forward and has a very clear application which makes sense to me. However if I would build one of these for you and charge you for it I would need to ask for more money than I am comfortable charging an individual with. (does that make sense?)

So - I would find this interesting if we could make say 100 or 1000 units and sell them at a profit. Maybe find interested people through Kickstarter once we have a working demo.

Do you think this is potentially possible?

Where are you located?

Looking for an electrical engineer with expertise in induction. Preferably in central Europe.

I need help designing a specialized charging mechanism for custom batteries.

Please e-mail me with CV and salary expectations @ paul dot strohmeier at gmail dot com.