Show Posts
Pages: 1 2 [3] 4 5 ... 19
31  Using Arduino / Programming Questions / Re: " 'analogWriteResolution()' was not declared in this scope " Error message on: February 03, 2014, 10:11:22 pm
The fully Arduino compatible Teensy 3 and Teensy 3.1 boards also provide this. At 1/4 the size and for a lot less money  smiley-cool
32  Using Arduino / Networking, Protocols, and Devices / Re: I2C: Buffers, Pull-Up Resistors and Transmission over UTP Queries on: February 03, 2014, 10:03:54 pm
Unless this is in a noisy (electrically) environment I don't think you'd need CAT6.
I my lighting systems I use pre-configured CAT5 cables with a PCA9600 I2C bus buffer and this works fine for up to 1MHz. I believe the max on the Arduino's is 400KHz so that would work fine on 20m.

The pull-up resistor configuration in Fig. 9 should work fine. Place the 470 Ohm resistors at each end of the bus. Or use a single 270Ohm pull-up resistor as shown in Fig 12.
The 4.7K on the Arduino side is a save value. The I2C pins for normal (100KHz) and fast mode (400KHz) pins only provide 3mA to discharge the cable(system) capacitance. Thus the limit to 400pF max system capacitance. Assuming a voltage of 5V and a pulp resistor of 1.8K result in a current of 28mA. 4.7K result in a current of 10mA according to Ohm law, so there is room to play.

Here is an excellent Article to the effect of varying pull-up resistors:
Everything Arduino <->I2C you'll find explained here:

In general I am not exactly sure why you chose the P82B715PN. You don't use other bus buffers in your system so thats one advantage that this buffer chip has that you cannot take advantage of in your system and it also does not isolate the bus capacitance which could help. I am thinking that a PCA9600 would be a better choice.
I could provide a schematic and a PCB layout that is breadboard ready.

The small board in the image below between the Ethernet Jack in the front and the Teensy 3 micro controller in the back hosts the PCA9600 I2C buffer chip, the Schottky diode and the necessary pull-up resistors. You'd need two of those little boards. One for each Arduino.
33  Development / Other Software Development / Re: Windows/Linux/Mac Eclipse plugin to compile and upload arduino sketches on: January 24, 2014, 07:18:12 pm

The Arduino Eclipse IDE bundles Eclipse Kepler and the plugin V2.2. No separate installation of the plugin is needed!
The only other software you have to install is Arduino IDE 1.5.2, or Arduino IDE 1.5.5 (NOT 1.5.4)

So, go ahead and compile and upload something ;-)
34  Development / Other Software Development / Re: Windows/Linux/Mac Eclipse plugin to compile and upload arduino sketches on: January 15, 2014, 10:28:16 pm
I've written some installation instructions for the newest version 2.2 and the new Arduino Eclipse IDE :

Particularly useful if you work on a mac and also want to program Teensy 3x boards! I've also installed the new Arduino Eclipse  IDE on Windows 7 and Ubuntu Linux, and find that the instructions should work for these as well.
35  Using Arduino / Networking, Protocols, and Devices / Re: Communicate with an iPhone through WiFi on: January 14, 2014, 06:38:29 pm
That's why I asked ;-)

The Ethernet->Router solution is dead simple and has the added advantage that you can use the mature Ethernet library which in turn is used by other Libraries.. Full Ad-Hoc or infrastructure abilities. Most routers are easy to configure per web interface, from the iPhone if you like.

A TP-Link WR702n costs $20-25 and a standard Ethernet Shield is maybe $30. Compare that with the price and functionality of the daead-on-arrival official  Arduino WiFi shield. You can get a little smaller, cheaper, and faster if you replace the Ethernet shield with a WIZ820io embedded Ethernet Module.

The only other small WiFi solution are breakout boards for the Texas Instruments CC3000. But then that module doesn't function as an AP either ( correct me if I am wrong, please!) and has to be connected to another router.

But even if WiFi provides more paths to a solution, the question with what application you are going to communicate and with which protocols is still not out of the world. You just have more options! I've chosen the OSC protocol and TouchOSC but that may not work at all for what you want to do.
36  Using Arduino / Networking, Protocols, and Devices / Re: Communicate with an iPhone through WiFi on: January 13, 2014, 10:11:12 pm
Besides the hardware, what software are you going to use to communicate with on the iPhone ?

37  Using Arduino / LEDs and Multiplexing / Re: Led Display on: January 06, 2014, 06:25:56 pm
While the OCTOWs library Paul has written for his Teensy3.x boards only works with Teensy boards the FastSPI2 library is also very popular for working with  WS28xx LED strings and also works on Megas. It's definitely fast enough to display still images ;-)
38  Using Arduino / LEDs and Multiplexing / Re: High Power RGB LED shield - 12bit/channel dimming - I2C (TWI) on: December 27, 2013, 09:09:44 pm
Finally, after a little eternity I've put my LED shield up for sale at

The difference to other offerings is that this shield is fully operated through the I2C bus (TWI) and requires only two pins (SDA, SCL) and GND. While the shield happily stacks in multiples on top of an Arduino Uno or Leonardo and most likely also a Yún and others it can be operated separately from the microprocessor.
So if your project requires:
  • independent control of more then 2 RGB LED's - it can do up to 64 -  and/or
  • a distributed system where each of the high power LEDs are many feet away from each other and/or
  • you need very smooth CIE lab brightness corrected dimming
Then this is what you are looking for.
Another "feature" is that these are assembled in the US, only use RoHS compliant, lead free solder solder and are fully function tested!

The best micro controller platform to use these with IMHO are the Teensy3.x as they have much more powerful I2C hardware than any Arduino I am aware of. They are fully Arduino compatible and Paul Stoffregen - the maker of these - is a very frequent contributor to the Arduino project.

I use a Teensy and these shields in my own lighting systems
39  Development / Other Hardware Development / Re: Led Stripe Light Organ / Flashing To Music / Need help on: December 26, 2013, 12:52:20 pm
There is a section on this forum entirely dedicated to LEDs and multiplexing. You may want to ask a moderator to move this thread to that section. You may get more responses :-)
40  Using Arduino / LEDs and Multiplexing / Re: Driving 750 or so leds, independently (of Course....why should this be easy?) on: December 26, 2013, 11:28:41 am
What speaks against using several length of LED strips instead of single LEDs ?

Using a Teensy3 or Teensy3.1 and the OCTOws library you can use thousands of LEDs at video refresh rates. The biggest project posted so far on the Teensy forum used in excess of 10000 LEDs in form of WS2811 led strips.
41  Using Arduino / LEDs and Multiplexing / Re: Very high powered LED's dimming - n00b on: December 26, 2013, 11:14:18 am
What you needn't addition to the LED(s) if you are going for a DIY product are four main components:

Power supply
Heatsink - available at eBay as well
Microcontroller - Arduino or compatible too  control PWM for dimming.
Constant  Current LED driver

There are heaps of el-cheapo Chinese products available on eBay with no documentation, total lack of competent or any customer support. There are several constant current drivers available on and also a few  Arduino shields that can be stacked directly onto an Arduino. Which one you use depends on your specific application.
42  Using Arduino / Project Guidance / Re: Wireless Surveillance System on: December 24, 2013, 06:50:34 am

Or give me example code for my project.
What part of your project as YOU going to do?
So plz give me code for this purpose. Thank You,
You know, this is a DIY forum. DIY stands for Do It Yourself. Start writing some code and when you encounter problems and things don't work as expected/ intended, then we'll help. The information you've provided is not detailed enough to write much more code than PaulS already has provided above ;-)
43  Using Arduino / Networking, Protocols, and Devices / Re: I2C question on: December 14, 2013, 04:27:56 pm
The data sheet states that the device uses a simple serial interface compatible with the SPI protocol. Why are you using I2C ?
SPI runs at much higher frequencies than I2C and can transfer much more data. Alas ofer shorter distances.
44  Using Arduino / Networking, Protocols, and Devices / Re: serial to osc on: December 14, 2013, 04:20:06 pm
Yup. I've come across the same problem when trying to connect TouchOSC to an Arduino ( well actually it was a Teensy3).
TouchOSC only receives and sends OSC messages and not OSC bundles.

Also, the library had a memory leak that had me scratch my head for a while but has been fixed in the meantime. You may want to download a fresh copy from The OSCuino GitHub site.
45  Using Arduino / LEDs and Multiplexing / Re: How to use a high current PWM LED controller on: December 14, 2013, 04:07:17 pm
This shield uses the powtec PT4115 LED driver. It is directly connected to the Arduino PWM pins. As GrumpyMike said, the AnalogWrite function will do for PWM dimming. Having that said, however, that leaves to be desired. The PT4115 has a dimming ratio of 5000:1 easily enough for 12bit dimming but the Arduino pins only allow 8- bit, at least in the AnalogWrite function.

There are ways to get some of the pins to dim at 16 bit, but I am not sure if that will work for all 6 PWM pins.
If you use both shields on the same Arduino Mega ADK you'll still only be able to control 6 independent channels, not 12 as both shields will use the same 6 PWM pins.
Pages: 1 2 [3] 4 5 ... 19