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What do you mean for "LED Monitor"?
Good points to start are some books:
https://www.amazon.com/Art-Electronics-Paul-Horowitz/dp/0521370957/ref=sr_1_1?s=books&ie=UTF8&qid=1387992275&sr=1-1&keywords=horowitz+electronics...
I toke the same link : https://www.powerstream.com/Wire_Size.htm
but i reported maximum current for power transmission (with a bit of safety margin), that was in my thoughts the most reasonable value, based in past experience as well.
For a "complete" chart, take a look here: https://forum.arduino.cc/index.php?PHPSESSID=mqsc963eks9ir0hjghlk7eui33&topic=118983.msg898023#msg898023
Anyway, that was a test under certain conditions, as explained in italian, is not an universal true; i always used 1.2k, but again my value is not...
These are approx AWG 20 (0.8 mm in diameter, 0.5 sq mm) and AWG 23 (0.56 mm in diameter, 0.25 sq mm), the maximum current should be 1.4A and 700mA (safe values) for copper wires.
The easy way is, as previously posted, a 555 monostable. What's wrong in a 555 monostable?
Do you prefer a bjt solution maybe? I can sketch one for you if u want.
What is your operating voltage?
3V isn't enough for a standard 555, unless you use a low voltage version, like LMC555
Regards
@themask
Of course, u have to choose one of these values, between 1k - 10k, the choice is related on many factors, as andre_teprom illustrated, for me, for example, 1.2k was the right value in many i2c atmel eeprom, but i can't just suggest this value, because different boards and different...
Sorry but i'm not experienced in 8051 architectures, i think u can find something from your IDE, i don't know what kind of language do you use (C, Assembly), or if u use Keil nor IAR, try to google "watchdog <yourIDEname>".
Sorry never worked with 8051.
Regards
Usually depends on your uController, in PIC Microchip there are option in the configuration words, in AVR Atmel there a fuses.
U can decide of switch it off, it's like working without protection... maybe 99% of times it's useless, but in some critical application, without watchdog, the process...
Watchdog timer, essentially, prevent processor from stall states, if something goes wrong with some instruction or some operation he reset the machine at the initial state. For that reason he have to be refilled periodically by the software for keep it far from zero (that means machine stuck)...
Constructors give a range 1k-10k for mainly one reason, different clock speed.
Your magic value, 2k, is maybe the best fit for your board, your device out/in capacitance, your clock speed, but isn't an universal law, so for this reason there is a range of values.
At an SCL of 100KHz or 400KHz...
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