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So you want an easy way to save power? : arduino. PowerSaving. NCP1117 D. OT-Hobbies-Heat. OT-HOBBIES Return to Resources page.


Voltage Regulator - Practical Power Dissipation Many people wonder why their Arduino boards get hot when they use Vin = 12V, and in fact, this issue comes up about once or twice a week on the Arduino Forum. The short answer is that most Arduino boards use small surface-mount (smt) voltage regulators, which get hot even at moderate load currents, and especially when larger Vin values are used. Many Arduino boards are advertised as having "1A" voltage regulators, but in the real world, you cannot run load currents anywheres close to this level, because of overheating. The real problem is that power dissipation and heating is related to both the voltage-drop across a device and the current through it, so the result is a "multiplicative" effect of the two factors, and not related to just the Vin or load current value alone.

Pd = Vdrop * Iload --> heat generated Once this relationship is grasped, the overheating issue is easily understood. EtherTen, Arduino Ethernet Shield Reset, Current and Voltage from USB. Here's some useful support notes on operating an EtherTen or Arduino with Arduino Ethernet Shield, both of which have a Wiznet W5100 Ethernet IC, an STM811 compatible reset IC controlling the W5100, and a microSD card on board.

EtherTen, Arduino Ethernet Shield Reset, Current and Voltage from USB

Is your EtherTen, or Arduino board with the current model Arduino Ethernet Shield not fully operating after reset or powerup? Here's some handy tips to sort it out. Most of this also covers regular Arduino boards and all kinds of shields when connected and powered by USB. The Reset IC connected to the Wiznet W5100 Ethernet IC is the very common STM811 or many compatible parts. This reset IC performs two functions: Firstly it holds the W5100 in reset if the VCC rail is less than 4.38V.

Ethernet Reset IC Delay The fix: Insert this line as the very first line in the void setup() { function in your project: delay( 50 ); // allow some time (50 ms) after powerup and sketch start, for the Wiznet W5100 Reset IC to release and come out of reset. Low Voltage From USB 1. Some Fun with a Cloned Arduino and W5100 Ethernet Shield - Chris Ramsay. This article mainly concerns the many trials of reliably bringing a remotely installed cloned Arduino and Wiznet W5100 Ethernet shield back to life after a power cut.

Some Fun with a Cloned Arduino and W5100 Ethernet Shield - Chris Ramsay

The W5100 board is being explored as an alternative to the cheaper 28J60 board which itself ended up with its own reliability issues as described here in another article. Please note that this particular article references DCcduinos only. The problems described within do not affect a genuine Arduino in my experience. The Issue - Unreliable Reset I had experienced a great number of issues with keeping a reliable connection between my network enabled Arduino, using the ENC28J60 module, and the rest of my home network once systems were installed out in the field.

The only way to get round the issue was to cycle the power to the system to bring it back to life. This worked flawlessly for nearly four months, and then system stability issues started to manifest themselves once again. Or so I thought... Mega 2560 5V regulator eventually fails if on external power only - Cobbleverse. Detect Lockups. If an Arduino program crashes in the forest, will it make a sound?

Detect Lockups

Unfortunately not. No blue screen of death, nor jarring squawk will alert you to the program’s doom. It will typically just quietly and unobtrusively stop running whatever robot, keypad or front door it is supposed to be looking after. In this article, I’ll show you how to use the watchdog timer to help track down the bug causing the lockup. But first, there’s a quick review of the watchdog timer itself for those new to the game.

The Arduino Watchdog Timer Most microcontrollers, including the Atmel chips using on the Arduino, have a watchdog timer. #include <avr/wdt.h> void setup() { Serial.begin(9600); wdt_enable(WDTO_1S); } void loop() { // the program is alive...for now. wdt_reset(); Serial.println("Hello"); while (1) ; // do nothing. the program will lockup here. A word of caution here: there is a bug in the early Mega2560 bootloader. Watchdog Interrupt and Reset An Arduino Crash Location Detection Example. Detect Lockups.