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106  Using Arduino / LEDs and Multiplexing / Re: PWM 3V 200mA High Power Led from 3v soure on: March 18, 2013, 05:39:58 pm

Apparently the only way is using a buck converter to ste-up the voltage and then use a CC driver?


A buck converter is a step down converter, not a step- up converter.
107  Using Arduino / Networking, Protocols, and Devices / Re: Ethernet UDP or TCPIP examples on: March 11, 2013, 03:57:34 pm
If you want to connect the Arduino/TP-Link to your home router that's what you use the Client mode for. Then you can control the Arduino through your home router. If you want to connect from an IPad directly to the TP-Link router you need to put it into AP mode.

What application are you using on the iPad ?
108  Using Arduino / LEDs and Multiplexing / Re: Problem with PWM output and sensor input on: March 09, 2013, 10:32:04 am
No code, no help :-)

Please put the code in code tags by using the hash button (#)
109  Using Arduino / LEDs and Multiplexing / Re: led fader project on: March 08, 2013, 07:41:02 pm
The " standard" PWM frequency on the Arduno boards is 500 Hz. Frequencies over 100-120hz are not visible to most people.
It may have more to do with the 8- bit resolution of the Ardinos PWM signal in combination with the non linearity of the human brightness perception.

In my own projects I use an Led driver board with 12 bit resolution, allowing me a CIE brightness corrected dimming, alas at about 120Hz (IIRC) PWM frequency. Smooth as butter dimming without any perceivable flicker.
110  Using Arduino / Networking, Protocols, and Devices / Re: Wire lib vs I2C lib - interrupts, performance. on: March 05, 2013, 09:39:11 pm
The I2c library is faster than the wire library. The values presented in the table are code-size in bytes and duration of whatever write read function. The calculation you did assumes that the first number given is the number of bytes transferred per time, which, again , is not what the numbers represent.
The I2C signals are realized in hardware, thus the likelyhood that your application will have to wait because of the " blocking" behavior is very small. Removing dependence on interrupts makes this library more flexible to use as it eliminates its chance of interfering with other libraries that may also want to use the same interrupts.

The reason this library worked better for me was because of the timeout and reset, a function the wire library does it offer, or at least did not when I write the software for my prject.
111  Using Arduino / LEDs and Multiplexing / Re: OctoWS2811 Library - for large LED display at video speed refresh on: March 03, 2013, 06:46:21 am
Hi Paul,

Pretty stellar work from you. as usual!
What you need is not a gamma correction but CIE lightness correction :
I've seen lookup tables for the above on the forum usually in 8 bit resolution and have one in 12 bit used for my LED shields for my projects

Even better would be true CIE lab color correction:
112  Using Arduino / LEDs and Multiplexing / Re: LED project help on: March 02, 2013, 09:53:03 am
The 20feet of CAT5 cable for the PWM would worry me a bit was well. I would expect some signal degradation particularly if the PWM is running at higher fequencies.
113  Using Arduino / LEDs and Multiplexing / Re: Full brightness multiplexing. on: March 01, 2013, 06:01:50 pm
The human eye is more sensitive to green light, so green LED usually appear brighter than the red, or the blue.
This article may also of interest if brightness perception is an issue:
114  Using Arduino / Networking, Protocols, and Devices / Re: Wire lib vs I2C lib - interrupts, performance. on: February 26, 2013, 06:57:22 pm
If you scroll down the page on you'll find a pretty detailed timing comparison between the I2C and wire library ;-)
That should explain any performance differences.
115  Using Arduino / Microcontrollers / Re: Teensy 2.0 Teensy Loader Error on: February 23, 2013, 07:34:36 pm
Perhaps you want to post your problems on the forum dedicated to the teensy boards:
116  Using Arduino / Networking, Protocols, and Devices / Re: Wifi connection???????? on: February 20, 2013, 06:56:16 pm
I read through your initial post again.
If you are interested in a real WiFi solution I would currently not recommend any WiFi shield and suggest an alternate solution using a " standard" Ethenet shield connected via short Ethernet Cable to a little pocket router. That way you will not have to rewrite code but still are able to use a WiFi connection:,149865.0.html
117  Using Arduino / Networking, Protocols, and Devices / Re: DIY Arduino WiFi? on: February 20, 2013, 06:51:18 pm
PaulS....I like your humor.....most of the time. This was the second time today that my kids asked me what I was laughing about when reading forum posts. That made an otherwise crappy day much better.

Here you go.
118  Using Arduino / Networking, Protocols, and Devices / Re: Arduino - Wifi - iPhone on: February 20, 2013, 06:43:48 pm
Just to summarize a few things

1. Using a little ( half the footprint of an iPhone 4 and about twice as thick)  TP-Link router will enable you to connect directly with the iPhone to the router/Arduino because that little router comes configured as an Access Point out of the box. You plug it in, it shows up in the WiFi connections in your iPhone and you're in business.

2. The TP-link TL WR703N is available through eBay ($20+) and I've had no one preventing me using it in my projects due to a missing FTZ certification YMMV. The user interface is in Chinese. Google translate helped me.

3. If you have a home router you can have the TP-Link also connect to your home router and access the Arduino wirelessly through your iPhone<-->home router <-->Tp-Link<-->Ethernet <-->Arduino. That is an interesting setup if your project is located somewhere inaccessible for a cabled Ethernet connection. I use this set-up in my projects (

4. You can also omit the Ethernet card and connect the TP-Link WR703N through its USB port directly to the Arduino, but it requires you to flash an OpenWRT Linux based router software on it to begin with. I have no handson experimece with this, but I believe that this will not work with Ardumote as Ardumote usesthe UDP protocol for communication and I am not aware of an Arduino library that supports UDP over USB. If that ever interests you, it is not required to purchase a preflashed one of eBay, unless The fine folks at the OpenWRT website are untruthful ;-)

5. The fact that Ardumote ( and TouchOSC, which I am using in my projects) work through the UDP protocol is also the reason why I would be careful with using a Bluetooth module. Getting that to work will almost always require you to socket programming and worse ;-)

6 Using Ardumote with the Ethernet shield directly or through the TP-Link Wr703n has worked flawlessly in my projects but I have since migrated to TouchOSC.
119  Using Arduino / Networking, Protocols, and Devices / Re: DIY Arduino WiFi? on: February 20, 2013, 06:14:05 pm
This should fit the bill.
120  Using Arduino / Networking, Protocols, and Devices / Re: Wifi connection???????? on: February 19, 2013, 08:00:52 pm
No. You just need to carefully read what's written before even attempting to touch the keyboard. The Xbee is N O T a WiFi solution. It's adheres to a different wireless standard but NOT WiFi. E.g. You cannot connect directly to it from an iPhone or Android phone or connect it to your internet router.
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