| Arduino Forum ::  Members :: James C4S
 Show Posts Pages: 1 2 3 [4] 5 6 ... 411
 46 Using Arduino / Project Guidance / Re: Arduino + Hue? on: July 20, 2014, 11:01:24 am Quote from: raschemmel on July 20, 2014, 10:53:21 amThanks but I think you can surmise from my post count that I already knew that.  I wasn't responding to you, duh.
 47 Using Arduino / Project Guidance / Re: Arduino Programs on: July 20, 2014, 10:28:48 am Quote from: blueOkiris on July 20, 2014, 09:57:49 amIt is an arduino with a 2.8 tft screen that I want to use for games and applications. Which Arduino?  Because if you're talking the popular 8-bit kind with a few k of RAM, I think you might need to re-consider what kind of "games" and "applications" it can run.
 48 Using Arduino / Project Guidance / Re: Arduino + Hue? on: July 20, 2014, 10:03:27 am Maybe start with this?https://github.com/bsalinas/ArduinoHueI used the complicated google search term "Arduino + Hue".
 49 Using Arduino / Project Guidance / Re: Arduino Programs on: July 20, 2014, 09:46:19 am A "hex code interpreter" is the processor itself.Is this what you want?http://bitlash.net/
 50 Using Arduino / General Electronics / Re: What capacitor will keep arduino live for 500ms? on: July 17, 2014, 09:27:48 am Here's how I calculate hold up.  Start with an equation that determines energy in terms of voltage and capacitance.  Then solve for C.E = (1/2 C * Vstart^2 -  1/2 C * Vdropout^2)For the algebra challenged, here's the steps broken down to solve for C.  1.  Take your circuit's current times the circuit's voltage, to get Power (then double it)   P = 2x (Voltage * Current)2.  Calculate energy required by multiplying power by time. E = Power x HoldUpTime3.  Calculate the V^2Vrange = Vstart^2 - Vdropout^24.  Solve for C.C = E / Vrange An Arduino board by itself draws 30-40mA depending on which regulator, so assume 50mA for margin.  The ATmega328 chip is only rated to 4V (or so) at 16MHz.  1.  P = 5V * 50mA = 250mW * 2 = 500mWThis is an extreme estimate.2. E = 500mW * 500mS = 250mJTime is 500mS (or recalculate for 100mS)3.  Vrange = 5^2 - 4^2 = 9VThe 4v dropout is probably higher than it really is, so you get some additional margin.4.  C = 250mJ / 9V = 0.02777 FSo thats 27mF or 27,778uF.I'd probably round up to a 33,000 or 47,000uF.  However, the whole calculation has lots of margins built into it, so its your call.No need for a Supercapacitor/EDLC.  You can get away with a regular aluminum electrolytic.  Not critical, but try to get the lowest ESR you can.
 51 Using Arduino / Programming Questions / Re: Using a short to prevent program form running on: July 17, 2014, 09:03:20 am Quote from: PeterH on July 17, 2014, 07:51:32 amQuote from: Jiggy-Ninja on July 16, 2014, 10:10:08 pmSpecifically, you need to configure it as INPUT_PULLUP.Not needed with the code posted, since that does a digitalWrite(pin, HIGH) which will enable the internal pull-up for input pins.Well, no.  Since the code posted configured the pin as an OUTPUT...
 52 Using Arduino / Programming Questions / Re: Using a short to prevent program form running on: July 16, 2014, 10:37:42 pm Quote from: abasel on July 16, 2014, 10:23:38 pmThanks for all of this but I am still battling to picture it all. Code:void setup(){        pinMode(13, INPUT_PULLUP); }This line tells the Arduino to make Pin 13 an INPUT and it connects a resistor internally to 5V (VCC).  So if *nothing* is connected to the pin, it is "pulled up" to a HIGH.  If the pin is connected to GND then the pin will be "pulled down" to a LOW.The key is the "_PULLUP".  Without that resistor, the pin's value would randomly float between a HIGH and LOW.Quote from: abasel on July 16, 2014, 10:23:38 pmand then in the loopCode:void loop(){    if (digitalRead(13)==LOW) {      //  The actual program....    }As I said above, when the pin is connected to GND, the pin goes LOW, so then the if-statement becomes TRUE and begins to execute.
 53 Using Arduino / Programming Questions / Re: Can you set up multiple delays in your program? on: July 16, 2014, 10:34:39 pm What do you mean "multiple delays"?Your code would benefit, significantly, from for-loops.http://arduino.cc/en/Tutorial/ForLoopCode:  alpha4.writeDigitAscii(3, '1');  alpha4.writeDisplay();  delay(1);  alpha4.writeDigitAscii(3, '2');  alpha4.writeDisplay();  delay(1);  alpha4.writeDigitAscii(3, '3');  alpha4.writeDisplay();  delay(1);  alpha4.writeDigitAscii(3, '4');  alpha4.writeDisplay();  delay(1);  alpha4.writeDigitAscii(3, '5');  alpha4.writeDisplay();  delay(1);  alpha4.writeDigitAscii(3, '6');  alpha4.writeDisplay();  delay(1);  alpha4.writeDigitAscii(3, '7');  alpha4.writeDisplay();  delay(1);  alpha4.writeDigitAscii(3, '8');  alpha4.writeDisplay();  delay(1);  alpha4.writeDigitAscii(3, '9');  alpha4.writeDisplay();Turns into:Code:  for(int i='1'; i =< '9'; i++) {    alpha4.writeDigitAscii(3, i);    alpha4.writeDisplay();    delay(1);  }If you got really clever, you could use function calls to cut down even more.
 54 Using Arduino / Installation & Troubleshooting / Re: Serial Monitor will not display anything on: July 16, 2014, 10:29:00 pm Code?
 55 Using Arduino / Networking, Protocols, and Devices / Re: Why Arduino can't connect over wireless network? (Wifi Shield) on: July 16, 2014, 10:25:45 pm WEP is basically no encryption anyway.
 56 Using Arduino / Installation & Troubleshooting / Re: "board at com3 is not available" on: July 16, 2014, 10:25:02 pm The board selected is "Due", not "2560".
 57 Using Arduino / Programming Questions / Re: Nontrivial compiling issues on: July 16, 2014, 04:01:04 pm Looks like an old library, pre-1.0.You might be able to get away with a simple change in LCD12864.cpp.Change "Wiring.h" to "Arduino.h".
 58 Using Arduino / Programming Questions / Re: Not writing to SD on: July 16, 2014, 03:58:49 pm Something non-obvious is going on if adding/removing seemingly unrelated code changes behavior.  Generally leads one to think of memory issues. Code:  unsigned long timelog[100];  int datalog[100];That's 600 bytes of of your 2048 bytes of RAM.  Plus serial, plus LiquidCrystal, and plus SD, maybe you're running out of RAM.For a test, drop your 100 elements (update your for-loops) down to 16 and see if that changes the behavior.Also, wrap all of your strings in F() tags like this:  sd.errorHalt(F("opening speed.txt for write failed"));   Serial.print(F("ADC: "));That'll keep them out of RAM.  F() won't work on the myFile.open(), so don't use it there.Also, what do you have going on here:Around line 48Code:  //for(int i = 0;1 < 3;i ++) {    for (int i = 0; i < 100; i ++) {this looks like you were trying to nest a  for() loop inside of another, but why are you using the same name for the increment variable?  Is this included in the "lcd code" you comment out?
 59 Using Arduino / Programming Questions / Re: Not writing to SD on: July 16, 2014, 03:23:50 pm Where are setting your SD/SPI chipSelect pin to an OUTPUT?
 60 Using Arduino / Programming Questions / Re: 'SD' not declared in this scope on: July 16, 2014, 01:33:08 pm And post the error messages you are getting.  Ideally both code and error messages wrapped in [code][/code] tags.
 Pages: 1 2 3 [4] 5 6 ... 411