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81
Quote
I hope that some day the compiler will be improved to actually remember the address space for each variable.
I think that the current version of avr-gcc has an __flash variable modifier as part of the "named address space" feature, along with a "universal" 24bit pointer.  Unfortunately, C++ doesn't seem to believe in the concept :-(, none of the avr-libc functions support the universal pointers, and it's usually easier and more efficient to deal with the two memories manually.
82
I am currently on a Uno and using the fastled library. Trying to find a simple method of converting the Arduino output to the 12V supply an using that to branch off to my 2 separate LED strings with their own 5V regulators. Was planning(questioning this now too) to step back down to 5V with a resistor zener setup.  I would prefer to use an optoisolator as everything else is optoisolated. The environment is extremely noisy and I can't let it get back to the 5V supply that the Arduino and the rest of my control circuit is on.

I honestly went into this part of the project quite ignorant and was having problems with the circuit on the breadboard before I realized the data string was at 800Khz. A 4n25 doesn't work at this speed, lol.

My scope shows only about 2. volts for the highs on the data string, is this normal? Figured that might be with the speed.

I haven't had any luck getting a 2n3904 or 2n2222 to saturate and turn on a 2n3906. Even removing the base resistors only helps a little, and they don't even get hot.   Obviously this looses my isolation, but I'm out of my element at this point.

Any comments or suggestions?

 
83
I'll take a swag (Scientific Wild A$$ed Guess) at it. Sounds like a noise issue. When you cut the rate in half, you increase noise rejection.

Consider this: When you are attached to USB, your Arduino ground is tied to the PC's ground and it probably has a DC path to earth which helps with noise rejection (in most cases). When you run untethered, your Arduino is ungrounded unless there is a path by way of a sensor.

I had a water pressure measurement system that worked while on USB but when running on battery, the sensor noise was so bad the signal was unusable. The culprit was stray 60hz mains noise being picked up by the high impedance sensor and no amount of filtering would help. In the end, a 0.1uf 500v film cap from common of the Arduino to earth (a nearby copper cold water pipe) solved the problem.
84
Bar Sport / Re: opinions on death .
Last post by DaveEvans - Today at 03:31 am
Some interesting reading on a similar subject (from a college class 30+ years ago).  And a summary and analysis.

85
Hi,

I'm using Arduino IDE 1.6.11 and update my ChipKit core to 1.3.0 with no problems. Now yesterday a new update 1.3.1 ChipKit core update. However this time I get CRC error, and I cannot go back to an older version. is there a way to remove this bad download from were ever it is stored? or is this a ChipKit website problem?

Luc
86
Arduino Zero / Re: Atsamd21g18 Bootloader
Last post by ericbaril72 - Today at 03:29 am
The Bootloader section is fuse protected.  You need to disable it first in order to be able to "erase" that seciont.

In Atmel Studio: tools -> Device Programming
   Selct your J-link, Make sure it can read the device ID

   Look into the FUSES section, Edit the BOOTPROT...
       Section 22.6.5    http://www.atmel.com/Images/Atmel-42181-SAM-D21_Datasheet.pdf

I too postponed the ready of those 1000's pages until I could no longer avoid it !

Luckily for you, the boot prot section is the shortest   ;-)     1 paragraph and 1 table

BOOTLOADER WORK:
I just finished porting my project to ASF ( including the SD card bootloader ) so I can make good use of the J-link box in "debug" mode and LOVE the ability to search function declaration in the entire project.

If you intend to keep the Arduino IDE, I would suggest you leave the original bootloader alone ( addr: 0x0000 - 0x2000 ) and implement your own bootloading requirements into 0x2000 to 0xXYZ and finally put your arduino sketch at the end ...

I do not know of many sketches that would require the "original bootlodaer 8KB" when you have 256kB available. 

You could take the original arduino bootloader to burn yours ( and have a backup plan when it fails ).  No need for a J-link or Atmel-ICE as the bootprot fuses are not protecting further and you would still need to learn the dreaded TOOLCHAIN by playing with the "start address".

good luck .

WARNING : when using the J-LINK ( and other debuggers ), they seem to interact with the WDT and clocking scheme.  The Arduino platform on the Zero

87
Say, do you have a paypal receipt number for that 20 bucks? Most recent payment I have from anyone was back in June, as far as I can see. Maybe I need to search for the actual transaction id.
88
Motors, Mechanics, and Power / microstepping
Last post by kevintshaver - Today at 03:27 am
Hi.

I have a PK266-02a vexta 2-phase 1.8 degee/step stepper hooked up to a Big Easy Driver with a 12V 1.5A power supply and an Ardunio Uno running the below sketch. This is based off of a bildr post.

The only problem I have is that instead of making 10 revolutions with stepper.moveTo(32000); I actually get 20. And it takes 1 sec/revolution with motorSpeed = 1600 steps per second instead of the expected 2 seconds.

I have nothing connected to MS1, MS2 or MS3 so I think it should be doing 1/16 microsteps. It behaves like 1/8 though. Any ideas why? Thanks.

Code: [Select]
int motorSpeed = 1600; //maximum steps per second (about 3rps / at 16 microsteps)
int motorAccel = 80000; //steps/second/second to accelerate

int motorDirPin = 8; //digital pin 2
int motorStepPin = 9; //digital pin 3

//set up the accelStepper intance
//the "1" tells it we are using a driver
AccelStepper stepper(1, motorStepPin, motorDirPin);



void setup(){
  stepper.setMaxSpeed(motorSpeed);
  stepper.setSpeed(motorSpeed);
  stepper.setAcceleration(motorAccel);
 
  stepper.moveTo(32000); //move 32000 steps (should be 10 rev)
}

void loop(){
 
  //if stepper is at desired location
  if (stepper.distanceToGo() == 0){
    //go the other way the same amount of steps
    //so if current position is 400 steps out, go position -400
    stepper.moveTo(-stepper.currentPosition());
  }
 

 
  //these must be called as often as possible to ensure smooth operation
  //any delay will cause jerky motion
  stepper.run();
}
89
My file structure is shown in the attachment.
The attachment doesn't show the "GHTS_Private" folder within the "libraries" folder.  It looks like you have "GHTS_Private.h" and "GHTS_Private.cpp" directly in the "libraries" folder.  Also, be sure to restart the IDE when you make changes to the libraries.
90
 I got a VS1838 HX1838 NEC Infrared IR Wireless Remote Control Sensor Module 21 button
as seen here
arduino-info.wikispaces.com

I have an 8 channel relay runs some lights in a loop / how would you run ir remote reciever loop listing for input from remote ie:
ir button 1 would turn on/off relay 1 ///  ir button 2 turn on/off 2 //// ir 8 on/off relay 8///
after delay(5000);
 return to standard relay/light loop(
ir remote on pin 11
relay on pins 13,12,5,10,9,8,7,6

I have been playing around with
code for the relay//lights built on blink so far
not too good with while loops could use some help/links 2 good code/ thanks all...

I started a google drive folder for the project
https://drive.google.com/folderview?id=0B5Sb7MnWeS7caFpFNTJYelNCTDQ&usp=sharing
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