Show Posts
Pages: [1] 2 3 ... 7
1  Using Arduino / Networking, Protocols, and Devices / Re: "Tiny RTC I2C Module" issue on: July 11, 2014, 12:03:35 pm
I have 4 of these DS1307 modules. Only one was working correctly, and I noticed that it has no resistor R7, where two of the modules do have an R7 resistor. After some googling I found that R7 connects to the crystal and this is not recommended. So I fired up the soldering iron and removed this super tiny resistor from the two modules that had it.  These two modules will now increment the time when not connected to 5V power, where before they would 'freeze' the time to what it was when the power was removed. My other module has a short on it somewhere, but is hardly worth the effort to track it down. I've spent too much troubleshooting these modules already.

If you look closely at the DS1307 modules on eBay, most of the newer modules will have R7 removed. (It is usually placed parallel to the Vcc/Gnd connection near the edge of the board.) That whole design for the DS1307 modules seems to be overkill to make them work with rechargeable batteries. The DS1307 should work for years with a non-rechargeable coin cell, and with a minimum of external components, without this added recharge circuit.

The DS3231 modules on ebay have dropped in price dramatically, and they are much more accurate and software compatible with the DS1307 code.  But these are obviously cloned chips at these prices, so caveat emptor.

-transfinite
2  Topics / Robotics / Re: Need help with a $4.00 dual moror controller , trying to build a robot on: July 02, 2014, 12:47:14 pm
There are lots of examples using an L298 motor controller with Arduino. Google is your friend.

Here is a site with some more detail on how to connect it.  This one is a shield, but the pins used are similar:

http://www.dfrobot.com/wiki/index.php?title=Arduino_Motor_Shield_%28L298N%29_%28SKU:DRI0009%29

It looks like your board has two options for power. You can use separate power supplies for the motors and the 5V logic (usually this is preferred). Or the board has a 5V regulator that can step down the motor power supply to provide 5V for the on board logic. Consult the schematic to be certain, and adjust the jumper accordingly.

-transfinite
3  Using Arduino / General Electronics / Re: Arduino UNO + Motor Shield Power problem on: May 07, 2014, 01:02:34 pm
What kind of 9V battery?  Motors require lots of current that your battery may not be able to provide. A laptop will provide around 500ma or more.

A 9V 'transistor' battery can power your Uno (connected through the voltage regulator), but not your motors usually.

-transfinite
4  Using Arduino / Programming Questions / Re: 1st code on: April 16, 2014, 10:54:29 am
It sounds like you need to uninstall and reinstall the IDE. All the examples should compile without errors.

The names of your variables or labels are up to you as long as the variables don't start with a number.

-transfinite
5  Using Arduino / General Electronics / Re: Open a door with a smartphone and an arduino uno on: April 16, 2014, 09:50:00 am
You can create a simple webserver on the Arduino that your phone can connect to with a browser to change the state of an LED. Once you have success with that, you can change the state of the door, as well as the LED.

There are a number of examples on the Arduino Playground that explain how to use the Ethernet shield to set up a webserver.

http://playground.arduino.cc/Main/InterfacingWithHardware#Communication
http://playground.arduino.cc/Code/WebServer

-transfinite
6  Using Arduino / Programming Questions / Re: 1st code on: April 16, 2014, 09:25:57 am
Even with no hardware, you can download the Arduino IDE and compile your code. If you do this you will find a number of simple errors.  Variables cannot start with a number.  So on line 27 change:
  const int 1ButtonPin = 2;
to
  const int ButtonPin1 = 2;

Same for lines 28, 29.  On line 58, bledPin is not defined.  You meant BledPin. 
1buttonState (line 36) is not defined, nor is 2buttonState or 3buttonState.

Most of these are just syntax errors that the compiler will find for you.

-transfinite
7  Using Arduino / Networking, Protocols, and Devices / Re: Establish connection between Arduino + Ethernet shield and Node.js web server. on: February 06, 2014, 05:24:04 pm
Not quite what you asked for, but take a look at bitlash-commander.  It provides some instruction for talking to Arduino with node.js:

  https://github.com/billroy/bitlash-commander

If you get it working, you'll be many steps closer to what you are trying to do.

-transfinite
8  Using Arduino / LEDs and Multiplexing / Re: How can I use multiple 3-digit 7-segment displays on: January 02, 2014, 01:37:40 pm
If you use i2c 7 segment displays, you can add multiple sets of digits fairly easily, otherwise, you may need a Mega to have enough pins.

Adafruit, and others have i2c 7 segment displays, but usually in sets of 4 not 3 as you need.  You can use the Adafruit matrix driver backpack to wire 3 sets of digits, and control them with i2c:  http://www.adafruit.com/products/1427

-transfinite
9  Using Arduino / LEDs and Multiplexing / Re: Bedroom led lightning on: January 02, 2014, 12:33:13 pm
Zambo,

The code doesn't look too bad to me. As for the wiring, that you may want to hide.   :-)
I'd consider using a prototype shield, and use point to point wiring to make it look neater, and more permanent. Then mount it in a plastic or wooden enclosure.

The second photo is really small, but it looks like a nice project. Is it bright enough that you don't need any additional room lighting?

-transfinite
10  Using Arduino / Networking, Protocols, and Devices / Re: rf2401 problem with mega 2560 on: December 18, 2013, 06:17:13 pm
The download link is on this page:
  https://github.com/maniacbug/RF24

Here is the direct link:
  https://github.com/maniacbug/RF24/archive/master.zip


-transfinite
11  Community / Exhibition / Gallery / Re: GPS time-date on: December 17, 2013, 05:38:13 pm
Nice write up. Thanks for the links to the GPS sources also.

I'm using Jack Christensen's timezone library to determine when daylight saving time hits, and update the GMT offset:

  https://github.com/JChristensen/Timezone

That would save you a switch at the expense of some flash.

It would be even cooler to use the GPS to determine the GMT offset depending upon the location of the GPS.  That's only useful if the clock plans to change location from time to time.

-transfinite
12  Using Arduino / Networking, Protocols, and Devices / Re: Please review my RF24 IoT network on: October 03, 2013, 09:06:32 pm
There's a bug in the new node code.  I added some print statements in the base to print the received temp, humidity, and pressure.  In the new node code I added one line to set the pressure to a constant:

  header.sensor.temp = 18.8;
  header.sensor.pressure = 30.1;

In the prior versions of node, I would receive the temp and pressure values on the base, but with the current version I receive an ovf (overflow) for the pressure. The temp is still ok. Seems like a fencepost error somewhere, but I haven't found it yet.

-transfinite

13  Using Arduino / Networking, Protocols, and Devices / Re: Arduino pro mini and nRF24l01 on: October 01, 2013, 04:17:41 pm
Since you've confirmed the LCD works, you should try a simple example sketch to test the communication between the nRF24l01+ modules.

Take a look at the examples here, using the mirf library: http://arduino-info.wikispaces.com/nRF24L01-Mirf-Examples

The 3.3V version of the pro mini should be a good match for the nRF24l01+ module.

-transfinite
14  Using Arduino / Networking, Protocols, and Devices / Re: Please review my RF24 IoT network on: October 01, 2013, 11:15:32 am
After having time to think about it (but not enough time to actually test it), the code I posted without the delay missed the point of checking for serial availability without pausing. The call to beARelay()is not supposed to be inside the if(currentMillis... block. That defeats the whole purpose of it.  To make it more explicit, I'd move the check for serial out of beARelay, and back into the main loop like this:

Code:
long previousMillis = 0;

void loop(void){
  unsigned long currentMillis = millis();

  if(currentMillis - previousMillis > 3000){
    previousMillis = currentMillis;
   
    header.ID = random(1, 0xffff);   // Identify this packet
    xmit(header.ID);                 // Send some data
    wait(MAX_RETRIES, header);       // Wait for it to be acknowledged
  }
 
  if (Serial.available()){
beARelay();
  }
}

Hopefully, that makes sense.

On large hop counts- I noticed that since the fix to the relay, I'm only seeing large hop counts when I'm at the edge of the radio's range.  I was seeing this when I moved a node upstairs.  I moved the relay just a few inches closer (and away from a metal lamp), and it ran overnight without a non-zero hop count.

I just ordered a RF24 radio with an external antenna to see how that affect the range.

-transfinite
15  Using Arduino / Networking, Protocols, and Devices / Re: Please review my RF24 IoT network on: September 30, 2013, 12:59:26 pm
That is more readable, but I don't understand why you reallocate header in xmit() and beARelay()when it is already a global variable. I'd leave the redeclaration of HEADER header out.

Also, as in the original node, the delay(3000) and then checking for Serial.available() just doesn't seem like a good idea. The delay should be removed, and replaced with something like:

Code:
long previousMillis = 0;

void loop(void){
  unsigned long currentMillis = millis();

  if(currentMillis - previousMillis > 3000) {
    previousMillis = currentMillis;
   
    header.ID = random(1, 0xffff);    // Identify this packet
    xmit(header.ID);                       // Send some data
    wait(MAX_RETRIES, header);       // Wait for it to be acknowledged
    beARelay();
  }
}

Otherwise, it's all good.

-transfinite
Pages: [1] 2 3 ... 7