Show Posts
Pages: 1 2 3 [4] 5 6 ... 597
46  Using Arduino / Sensors / Re: Hi all on: September 08, 2014, 08:52:53 am
An IR Remote does not send ASCII characters that match the characters printed on the key.  They will send a key code for the key you press.  Part of your job will be mapping key codes to ASCII characters.

Once you have mapped an incoming key code to an ASCII character you save the character as you would any other keyboard input.  Look at any of the many keypad-lock examples.
47  Using Arduino / Sensors / Re: Does INA128/129 need negative voltage or can I use GND? on: September 08, 2014, 08:41:07 am
If you want a single-supply instrumentation amplifier you might want to try the TI INA122:
48  Topics / Home Automation and Networked Objects / Re: Arduino Uno Voltage on: September 08, 2014, 08:28:13 am
The current drawn from the voltage regulator depends on the Arduino design (about 50 or 60 mA) plus what is attached to the 5V and data pins of your Arduino.  The power dissipated by the regulator depends on that current and the difference between input and output voltage.  For example if your Arduino and peripherals draw 400 mA at 5V and you are feeding the regulator with 7V (minimum recommended voltage) the regulator has to dissipate 2V*0.4A = 0.8W.  If you feed the regulator with 12V (the maximum recommended) it will dissipate 7V*0.4A = 2.8W.  It will get MUCH hotter.

If your Arduino won't run off USB power it is trying to draw more than 500 mA.  You might want to figure out where all that power is going and figure out a lower-power way to do the same thing.

If you replace the 12V supply with  a 7V supply you will be much less likely to burn out the regulator.
49  Using Arduino / Sensors / Re: RF Antenna on: September 08, 2014, 08:16:47 am
A Google search for 433MHz antenna should turn up design details.  Typically it would be 1/4 wavelength piece of bare wire.
50  Community / Gigs and Collaborations / Re: Paid Help needed please on: September 08, 2014, 08:09:48 am
The most common problem when trying to run two patterns in parallel is using 'delay' for timing.  The 'Blink Without Delay' example shows a way of generating a lighting pattern using the millis() function rather than delay().

The first step is a rough specification of the two patterns.  How often are the strobes?  What levels do the dimming and fading light hit, in what order, and with what timing?
51  Using Arduino / Sensors / Re: strange readings with hall sensor on: September 08, 2014, 06:45:28 am
all the tutorials use the 4 pin arduino button; I have just 2 wires, where do I connect ground?

The four pins of the typical tactile button are just two connections.  Two pins go to one side of the switch and two pins go to the other side of the switch.
52  Using Arduino / Programming Questions / Re: Avrdude Uno EEPROM dump - garbage data on: September 07, 2014, 10:17:09 am
If you are not using an ISP device it is possible that the bootloader does not support reading the eeprom segment.
53  Using Arduino / Project Guidance / Re: Checking the RAMPS 1.4 on: September 07, 2014, 08:26:05 am
I would start by removing the RAMPS board and checking that the Arduino Mega can upload and run a simple program like Blink.  If that works you could then write a little sketch to pulse the five stepper drivers.  Plug in one stepper board at a time with a stepper motor attached to see if the stepper driver works.  If a working stepper driver works in all five positions then you are most likely in luck.
54  Using Arduino / Programming Questions / Re: Serial read problem on: September 07, 2014, 08:15:41 am
1, why x+1? array aren't supposed to start from 0? isn't     text[x++] = c;  the same thing as     text[1] = c; when it starts copying bytes from

2,  text
  • = '\0';  // Add null terminator;  won't this overwrite the last character?

3,  why need to use another variable char c? since text array is already a char type;

1)  x++ means increment x AFTER the expression has been evaluated:
x = 0;
text[x++] = c;
// is equivalent to:
x = 0;
text[x] = c;
x += 1;

2) No, the value of x is incremented AFTER it is used.
x = 0;
text[x++] = c;
text[x] = '\0';
// is equivalent to:
x = 0;
text[x] = c;
x += 1;
text[x] = '\0';

3)  Using 'c' to store the received character is easier than storing it in the array and referring to it as element x-1:
x = 0;
text[x++] =;
// Now that x has been incremented the character is in text[x-1];
if (text[x-1] == '\\') {
55  Products / Arduino GSM Shield / Re: GSM library: What is the voiceCallStatus "CALLING" good for? on: September 07, 2014, 08:04:40 am
you also dont get appropiate response after using the .hang() method

it sorta makes sense, but it doesnt. i mean, one has to be able to change the voiceCallStatus through hangCall() as well as through voiceCall() to build a device that always knows its status, right?

You should read:

Those will show you how the library implements synchronous voice calls.  After the call to .hang() it will call .ready() until it returns true or until a timeout occurs.  Perhaps if you do that the .getvoiceCallStatus() will return IDLE_CALL.
56  Using Arduino / Programming Questions / Re: Serial read problem on: September 07, 2014, 06:06:12 am
Try this:
char text[70];
int x=0;

void setup(){

void loop() {
  if (Serial.available()) {
    char c =;
    text[x++] = c;
    text[x] = '\0';  // Add null terminator
    if(c == '\\') {
      Serial.print ("received:");
      Serial.println (text); 
    Serial.print("text: ");

    Serial.print("text[x-1]: ");

    Serial.print("x: ");

57  Using Arduino / Programming Questions / Re: Serial read problem on: September 07, 2014, 05:40:45 am
      if(text[x]==char(92)){    //  \, dec: 92, hex: 5C, oct: 134, bin: 1011100 

You are filling in text
  • , changing x to x+1, and then comparing text[x+1] to '\'.
58  Using Arduino / Sensors / Re: strange readings with hall sensor on: September 06, 2014, 11:34:31 am
Sounds like your "hall effect sensor" is actually a magnetic reed switch.  Try treating it like a pushbutton: include a pull-up or pull-down resistor so the input is not left floating when the switch is open.
59  Topics / Robotics / Re: Help in the components of the quad copter on: September 06, 2014, 11:04:03 am
ArduCopter is a model of flight controller.,3828-3.html
60  Development / Other Software Development / Re: libraries on: September 05, 2014, 07:47:46 pm
Here is a library for I2C (SDA/SCL) interface LCD displays:
Pages: 1 2 3 [4] 5 6 ... 597