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1  Using Arduino / LEDs and Multiplexing / Re: 10 W LED with Tinkerkit MOSFET on: March 05, 2014, 07:32:11 pm
8,4V DC - regulated ?  (should be)
Put a capacitor parallell to led.
PWM dutycycle out to MOSFET is 0/255..255/255
--------------
Post code and schematic..

It is the current that needs to be kept constant, not the voltage. Otherwise you'll kill the LED in time.
2  Using Arduino / Networking, Protocols, and Devices / Re: Reading a OSC message from Arduino on: March 03, 2014, 11:10:42 pm
You am actually have more luck using this library for your Ethernet shield :
http://forum.arduino.cc/index.php?topic=178024.120

It's API looks much closer to the Ethernet library than the on you linked to.
3  Using Arduino / Networking, Protocols, and Devices / Re: Reading a OSC message from Arduino on: March 03, 2014, 06:58:35 pm
there are several reasons why this does not work:

1. The readme on the CNMat site says "- Sends and receives OSC packets over transport layers that implements the Arduino Stream Class such as Serial and  Ethernet UDP" I don't think the ENC28J60 library does that. EthernetUDP is part of the Ethernet library that works with the Ethernet Shield or in general with Shields and embedded Ethernet Modules that use an Wiznet W5100 or W5200 chip.
In essence the library that comes with the ENC28J60 would have to implement the pure virtual methods defined in  UDP.h. I haven't looked at it in detail but, again, I don't think it does that.

2. In order to use the OSCuino library you first have to receive a UDP package before you can fill the OSC message object with  msg.fiill.  Here is a little code snippet from one of my sketches that shoes how to receive a UDP packet and then fill the OSCmessage with msgIN.fill and then parse and route it to a callback function with msgIN.route().

Code:
void msgReceive(){
OSCMessage msgIN;
int size;
if((size = Udp.parsePacket())>0){
while(size--)
msgIN.fill(Udp.read());
if(!msgIN.hasError()){
msgIN.route("/analog", handleAnalog);
msgIN.route("/digital", handleDigital);
}
}
}
4  Development / Other Software Development / Re: Windows/Linux/Mac Eclipse plugin to compile and upload arduino sketches on: March 01, 2014, 08:04:39 am
I have written detailed installation instruction for Mac users here:

http://trippylighting.com/teensy-arduino-ect/arduino-eclipse-plugin/arduino-eclipse-ide-and-plugin-v2-2-installation/

These are to be followed precisely. If it says Arduino 1.5.2 then don't attempt to use 1.5.6 because it is more convenient ;-)

Also, I would really appreciate feedback on these instructions (there's a Windows version as well). I have anywhere between 40-50 visitors with 2-3 views per visitor on that section of my tiny blog and rarely receive any feedback. Occasionally a user asks question and needs help, but once I provide direction I don't necessarily receive feedback if it actually helped.
5  Using Arduino / Networking, Protocols, and Devices / Re: Cu Head and Cisco AP on: February 26, 2014, 12:46:58 pm
Qute frankly, I would put that WiFi shiled into the recycling bin.
The design of this shield is many years old and uses an embedded TCP stack that is not trivial to handle. I'fe tried this shiled almost 3 years ago and while I fibnally got it to connect, and send UDP packages, I ran into one obstacle after another.

In the meantime I have foud the most reliable solution is an Ethernet Shield comnnected to a WiFi ppocket route such as the TP-Link TL WR703n (or 702 or 3020).
If it needs to be physically smaller then use a Teensy (www.pjrc.com) connected to a WIZ820io.

Other than that a CC3000 perhas from Adafruit may do the job and is better software supported.
6  Using Arduino / Networking, Protocols, and Devices / Re: Ethernet Shield vs Wifi Shield on: February 26, 2014, 12:40:51 pm
Being a newbie and wanting to finish a project like this within a week is illusory at best!!!
This project will require you to do software programming.

If it has to be WiFi then get an Ethernet Shield for the reasons already outlined and connect it to a littel relatively inexpensive pocket WiFi router such as the TP-Link WR702n, which can be had for less than $20.
7  Using Arduino / Networking, Protocols, and Devices / Re: Connection WI FI on: February 26, 2014, 12:22:03 pm
The solution that's the easiest ald very likely also the most flexible and reliable has already been suggested:

Use a "stadard" Arduin Ethernet Shield and connect it per Ethernet Cable to a small WiFi router. e.g. the TP-Link TL WR703n (or use the 702n or the 3020).

The benefits of this approacha are:

- less expensive than a single Arduino WiFi Shield
- You can use all the libraries and Sketches that are written for the Ethernet Shield.

If it has to be small I'd use a CC3000 from Adafruit, but makle sure you'll evaluate what what you want to achieve in detail (what protocols to use etc.) and compare with specs and available libraries.

I use a Teensy++2 and a WIZ812MJ as well as a Teensy 3 connected to a WIZ820io  connected to a TP-Link TL WR703n in my projects and it has not let me down.
8  Using Arduino / Networking, Protocols, and Devices / Re: The best way to connect my mesh network to the company Wifi. on: February 21, 2014, 09:27:56 am
If you're looking for a potentially painful laerning experience then use the WiFi shield.

I personaly use have used an Ethernet Shield connected to a little WiFi pocket router in client/bridge mode. that combination, while more bulky, IMHO still offers the most flexibility and works out of the box. You can use the standard Ethernet library and all it offers in matured functionality. DHCP, DNS, mDNS etc.

As I mostly work with Teensy boards (www.pjrc.com)  I now successfully have used a WIZ820io Ethernet module in conjunction with a TP-Link TL WR703n and TL WR702n in a few projects.

This solution is more functional solution and less expesive than the WiFi shield.
9  Development / Other Software Development / Re: Windows/Linux/Mac Eclipse plugin to compile and upload arduino sketches on: February 21, 2014, 06:39:28 am
You may want to dart with the instructions on my blog:

http://trippylighting.com/teensy-arduino-ect/arduino-eclipse-plugin/arduino-eclipse-plugin-installation-2/
10  Using Arduino / Networking, Protocols, and Devices / Re: Multiple I2C sensors questions on: February 05, 2014, 09:14:28 pm
When you use different voltage levels it is good practice to use a  Level shifter. The one below for Adafruit should work fine:
http://www.adafruit.com/products/757
This already includes 10k pull-up resistors.

It is really very simple to calculate pullup resistor values but requires a little bit of I2C bus spec. knowledge.
The I2C pins for normal mode (100KHz) and fast mode (400KHz) can only sink 3mA, which is also the reason why the overall bus capacitance should not exceed 400pF. Assuming a 5V I2C bus and A 1.8k resistor, according to ohm law  2.8 mA of current flow through the resistor. So in essence a 1k resistor is too low and the likelihood that the pins still are able to pull the I2C lines below the logic zero level is small.
11  Using Arduino / Networking, Protocols, and Devices / Re: I2C: Buffers, Pull-Up Resistors and Transmission over UTP Queries on: February 05, 2014, 08:49:52 pm
I suggested the PCA9600 because it is much more flexible and much faster and because I have a functioning board design tested to work on 20ft of CAT5 cable and 8 devices on the I2C bus at 1MHz showing still very crisp signals on a scope.

However, the chip you have selected should work fine for your application and  promises to be even simpler in application. For example it does not require the fast switching schottky diodes in my circuitry. The image I referenced is described as the quick design reference in the data sheet for the P82B715. I don't exactly know what your application is but I doubt you'll need the ESD protection diodes shown in the picture so all you are left with for a schematic are two chips and a few pull-up resistors.

I would not worry too much about the pairing. Just follow the schematic  shown in Fig 9 in the data sheet and you should be fine. That schematic does not show any decoupling caps either ;-)

Now go and build the thing and see if it works! Don't expect for it to work the first time. That of course does not mean that it won't but it is relatively normal that things have to be tweaked. Should you do run into problems, an oscilloscope is a very helpful tool to verify signal levels and signal Integrity. A logic analyzer is a very helpful tool to debug I2C protocol ( software) issues. For I2C bus purposes neither of these need to be particularly expensive. A good used analog scope for $50 from eBay is well worth the investment and plenty enough to verify I2C signal problems.
12  Using Arduino / LEDs and Multiplexing / Re: need help with 3w led wiring and high power arduino shield on: February 05, 2014, 07:32:29 pm
Don't wire LEDs in parallel. However when you flow this advice then you'll find that 8 x Vf is alway higher then the 12V from the computer. When something does not work as expected, turn of the power, take a step back and do some basic calculations.

The shield does not look like a constant current driver, which is what you need to drive LEDs. YourLED's might already be damaged if they've seen more than their rated max current.

Computer PSU's have the problem that they often do funny things when no load is applied to them. Not very good choice either.

Before making any more wiring attempts please browse through this section o the forum to brush up on your LED know how ;-)
13  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
14  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:
http://dsscircuits.com/index.php/articles/47-effects-of-varying-i2c-pull-up-resistors
Everything Arduino <->I2C you'll find explained here:
http://www.gammon.com.au/forum/?id=10896

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.
15  Development / Other Software Development / Re: Windows/Linux/Mac Eclipse plugin to compile and upload arduino sketches on: January 24, 2014, 07:18:12 pm
@timbopoise

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 ;-)
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