arduino autoreset, watchdog timer

I found this excellent video for using arduino watchdog timer created by Make Course. highly suggestive!

Software Reset of Arduino

The term "software reset" reffers to reset the arduino by internal codes. Generally there are three ways to reset arduino automatically:
1. use watchdog: an external hardware that activate the arduino reset function. The safest and most reliable way to do an automatic arduino reset.
2. use output pins with relay: when the pin is written to HIGH, it's attached relay connects the reset pin to Gnd, and that activates the reset function.
3. use software reset code: this only reset the running programm. This reset will command arduino to run the programm code from the beggining. (Bootloader, for example, will not be reset.)

It is useful to run automatic reset when using arduino for prototype of long-term usage.

Sofware reset can be done by some means:
1.  void(* resetFunc) (void) = 0;
Declare this function in the code and when calling resetFunc(); the programm wil be reset.
2. void resetFunc() {  asm volatile ("  jmp 0");  }
This is the other way to declare the reset function.

Reference:
http://forum.arduino.cc/index.php?topic=49581.0
http://www.xappsoftware.com/wordpress/2013/06/24/three-ways-to-reset-an-arduino-board-by-code/
http://www.instructables.com/id/two-ways-to-reset-arduino-in-software/step2/using-just-software/

USE TLC5940 on Arduino Leonardo

The TLC5490 library (http://playground.arduino.cc/learning/TLC5940 ) should be modified to be working with Arduino Leonardo. The Solution can be found here:
http://forum.arduino.cc/index.php?topic=110394.0
I went through all the process and this solution works fine. This post is my documentation.

Upgrade Arduino WiFi-Shield firmware

I am newly studying the interaction between arduino and xively.com. The interaction was first designed for arduino ethernet but now I need the sketch run with WiFi. I use the WiFi shield and Arduino MEGA 2560. Although the internet seems work, my arduino just cannot get the xively data from internet. Even the example sketch of "wifi web client" doesn't work properly.

Finally I tried to update the firmware on my wifi shield. The introduction from the official arduino page is correct but lacks clear step-by-step explaination. Some other online solutions don't work on my shield. This article is written after my finally finshing the update and solving some problems. The final process I found out is actually relative simple and requires only a few downloads (I use windows):

Arduino ATtiny 84/85 (updated 2020/8/4)

ATtiny allows you to reduce the cost of your electronic prototype, even lower than Arduino Mini series. ATtiny84 or 85 is microcontroller from Atmel. ATtiny85 offers 6 I/O pins for communication and 8192 byte memory, and ATtiny 84 12 I/O pins and 8192 byte. You can use Arduino IDE to make a sketch and upload onto this tiny IC. To do that, you need to set up your Arduino as an ISP (In-System Programming).

I think, the original developers using ATtiny for Arduino projects are from High-Low Tech Lab of MIT (2009-2014). Visit their page for more information: http://highlowtech.org/ 

This post shows you how to use ATtiny84/85 for your project and other recent updates. 

ATtiny85

controll arduino online

If you need to controll arduino or other electronics remote. Here is a useful website for you.
https://sites.google.com/site/ixacproject/

How to get start with arduino

Although there is a tutorial on the arduino website, it still seems difficult for the beginers to learn arduino program. I think the problem is that the examples are categorized after special themes, and the difficulties in each theme are quite different. Here I would like to offer a list of examples for the arduino beginers who tries to learn this program by their own. You may do the toturial examples according to my list one after one so that they can learn this program and codes more easily.

The first, get a arduino board Uno and downlad arduino sofware,

and install the board on the computer under this introduction,

Now comes the list. When you start an example, you should try to understand every single code. You may not be able to understand them all, and that's why you need to look the unfamiliar codes up in it's reference parallelly. I believe, if you can finish the first 10 examples, you will get a global understanding about how to program the arduino board. For the beginers who use arduino for building prototype will need to finish the first 15 examples. Example 16~19 are for sound functions of arduino. If you don't need sound functions, you can just skip them. If you can understand the all 22 examples, I believe you will have the ability to study other tutorial examples or you can start learning arduino by studying each language coad in the Reference freely.

List:
01. BareMinimum
02. Blink
03. DigitalReadSerial
04. Button (The circuit picture in this example lacks an LED. You should connect an LED to Arduino board the same like the 02.Blink example.)
05. If Statement
05-2. You should now study "Comparison Operators" in the Reference.
06. For Loop
07. Knock
08. Analog Input
09. Analog Read Serial
10. Analog InOut Serial
11. Fading
12. Smoothing
13. Knob
14. Sweb
15. Motorknob
16. Tone
17. Pitch Follower
18. Simple Keyboard
19. Tone 4
20. While Loop
21. Switch Case
22. Switch Case 2
22-2. You should now study "Boolean Operators" in the Reference.