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1  Community / Bar Sport / Re: Grrrrr crappy components on: September 16, 2014, 09:10:17 pm
What is the tolerance of those caps? Some of them are rated -50%, +100% might still be in spec, or you got the edge spec ones after someone else paid a bit more for the more accurate ones...
2  Community / Bar Sport / Re: Who hasn't accidentally touched a mains voltage once or twice? on: September 16, 2014, 09:07:04 pm
120VAC, 440VAC and 600VDC.

120VAC is just a mild twitch and one actually feels pretty god afterwords. Work on servicing machinery and you will hit it from time to time and some of those fool engineers can really find some fun ways to hide 120V for you to find...

440VAC one time had a couple little burn marks on my arm. 2 spots a couple inches apart.

600VDC from the high voltage connection on a couple 6BG6 tube in a 60W Heathkit CW Transmitter. (if you have to ask, it will take to long to explain) Don't really remember touching it, but I do remember running into the door frame and seeing my hands in front of me, opening and closing as they slowly came out of the fog. And somehow my glasses were in the next room, behind me on the floor. Seemed like every nerve in my body was buzzing.

Never got into it, but 270VAC has the reputation for being the worst voltage to get into. Don't know why, from any personal experience, but that is its reputation.
3  Community / Bar Sport / Re: How to start an argument on internet on: September 16, 2014, 08:52:34 pm
C or c was developed as a low level language for systems development. (about as close to assembly as one could get without using assembly) Then some folks decided that to use anything else was evidence that the programmer was really a moron and beneath contempt. And so they formed a COMMITTEE and it became this gross, unwieldly thing called C++ with more rules and everything got redefined (methods???) and became much harder to use and the programs became more bloated to support all the new stuff developed by the COMMITTEE.

And meanwhile there are other languages that make applications very easy to write, but anyone that would use one of them is less than worthless because they didn't us c/C++...

Most of the Arduino is based on c. Considering the ram size, many of the constructs of C++ are not really practical and can easily be memory hogs.

(Think this will start an argument?)
4  Using Arduino / Motors, Mechanics, and Power / Re: Brushless motor OR servomotor on: August 20, 2014, 08:05:14 pm
Are you looking for a hobby type servo or an industrial type servo? What exactly are you trying to do?
5  Using Arduino / Storage / Re: RAM disk on: May 06, 2014, 09:14:43 pm
If you don't have room for an array in memory you might look at a small static ram. How many pins do you have free?
6  Community / Bar Sport / Re: teaching debugging on: March 19, 2014, 09:46:05 pm
Another reason some might be out of ideas is this - They wrote the code and just cannot see the obvious error in their own code. Someone else looks at it and it is glaringly obvious. I get away from coding for a bit and this particular problem creeps up.  So you leave the code alone for a day or two and then take a look at it again and you sort of wonder what idiot made that obvious mistake... Same reason I used to hand my drafting designs to one of the other guys in the engineering department. He didn't know what I was drawing and he could spot the missing dimension before I released that part to the shop.
7  Using Arduino / Motors, Mechanics, and Power / Re: Need help with writing code for two stepper motors on: March 19, 2014, 09:20:49 pm
Make your own drivers - http://forum.arduino.cc/index.php/topic,84809.0.html - is one I did using ATtiny2313. The transistors you use can be sized for the current you need to drive your motors.
8  Using Arduino / Microcontrollers / Re: attiny85/84 as stepper motor controller for miniCNC milling? on: March 19, 2014, 09:15:07 pm
Take a look at this - http://forum.arduino.cc/index.php/topic,84809.0.html

I used an ATtiny2212. has a few more pins than needed but that is generally easy to deal with...

Started out in Arduino but went to Assembly for the final.

Easy to do regular stepping, wave stepping or half stepping. Could use some of the unused pins to select.
9  Using Arduino / Storage / Re: Building a working flash memory programmer. on: January 03, 2014, 03:49:20 pm
And here is a board layout. Single Sided, Red lines are wires on the top side of the board, and blue are teh traces on the bottom.
10  Community / Bar Sport / Re: What do you call a citizen of the United States of America? on: January 03, 2014, 10:28:58 am
Merican is sort of like Yank or Brit or Limey (or Jack) or Frog or a host of other nicknames that we have all come up with for those originating from other places. And whether it is taken as an insult depends on the attitude of the one receiving the comment. Some can be offended just by saying "Good Morning" to them and others just let it roll off and don't make anything of the comment. And some of these names have little meaning in one region, and are heavily loaded in another regin.
11  Using Arduino / Programming Questions / Re: Arduino Port Manipulation - Reading Port Data on: January 02, 2014, 06:25:30 pm
Reading an encoder is a good application for using an interrupt. Trying to keep a loop fast enough to read an encoder with more than just a few counts per revolution is an exercise in futility in Arduino C. You have to account for the software overhead of the language and there is just too much going on to be able to read I/O fast enough for an encoder.

The exact routine you use to read the encoder depends on the resolution you need. There are 4 states - A on- B on, A On- B off, A off-B off, A off-B-on. With 1 interrupt (Change on Signal A) you can use these states to tell forward or reverse rotation of the encodet and a resolution of 1/2 the encoder lines.
12  Using Arduino / General Electronics / Re: New PCB production tool on: January 02, 2014, 01:57:14 pm
For a 1 sided board I should make an adapter for my plotter and print directly on the board.  Tape the board to a piece of 8.5 x 11 paper. Thanks
13  Using Arduino / Microcontrollers / Re: Stops at 1778 bytes without errors on: January 02, 2014, 01:20:00 pm
Function typing. You have a number of functions of type int that have no return. Should they be type void?
14  Using Arduino / General Electronics / Re: Coin cell on: January 02, 2014, 01:10:08 pm
Coin cells are low current devices. They can't supply enough current to power the Arduino. Might have to use 6 or more in parallel to supply enough current. Would be better served with AA's or AAA's., but they will discharge rather quickly.
15  Using Arduino / Microcontrollers / Re: Out of memory Attiny2313 on: January 02, 2014, 01:06:49 pm
I must say that in some way I disappointed because the low flash memory of this chip, I really don't check the amount of memory before  to buy it (my bad), I just count the 18 pins and all the ports and the 4 pmw  pins that it has.

but I have learned some stuff about the memory and how to keep it low, I could reduce a 2202 bytes sketch to 2000 bytes just below the 2048 of the attiny2313.

after a rest and go to hear the message, thinking about other tings....
I couldn't understand how a micro with a "lot of pins" just has 2k of flash or at last 2k must be enough to handle all the pins , the ting is that I'm believe that the arduino's IDE is keeping more memory that it must in other way for example the simplest sketch keeps 310 bytes, and  adding one pinMode(); isntruction it reaches 508 bytes.
Code:


void setup(){}
void loop(){}

please some advice in front of this matter


I come a bit late to this...

But the part numbers tell you how much flash and ram you have to work with. The memory avail is not a function of the number of pins, but rather the size of the die inside the chip.  32K in an arduino is a bit absurd, in my opinion, but cost wise it makes sense, as the chips with less ram aren't much cheaper. Like someone else said, if you need more memory, go for the 4313. twice the flash, same pinout.

Using your logic I should be complaining that the 2313 has too much memory. I programmed a 2131 as a stepper controller. 1200 bytes in Arduino. Wanted it faster, 88 bytes in assembler. No RAM usage as everything is in registers.

Waht you need to aks is this - Is your code as efficient as possible? Not sure what your programming experience is, but folks with PC programming experience can sometimes write some rather bloated code because there is so much memory and so much storage that it doesn't really matter. As you code the Tiny series of chips you really need to think about the memory cost of every bit of code you write.  Is it necessary, and could it be coded cleaner?
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