Lecture 1 - Background and Power Supply
http://tiny.cc/gabis
http://www.sparkfun.com/
Ma hakkasin lugema seda teksti ja olgugi, et see on mõeldud algajatele, tuli ikkagi kohe haarata Wikipedia järele.
Mõisted:
DIP - Dual in-line package
In microelectronics, a dual in-line package (DIP), sometimes called a DIL-package (for Dual In Line-package),[1] is an electronic device package with a rectangular housing and two parallel rows of electrical connecting pins. The pins are all parallel, point downward, and extend past the bottom plane of the package at least enough to be through-hole mounted to a printed circuit board (PCB), i.e. to pass through holes on the PCB and be soldered on the other side.
IC - Integrated circuit
In electronics, an integrated circuit (also known as IC, microcircuit, microchip, silicon chip, or chip) is a miniaturized electronic circuit (consisting mainly of semiconductor devices, as well as passive components) that has been manufactured in the surface of a thin substrate of semiconductor material.
MIP - million instructions per second
(Allikas: Wikipedia)
Märkmed:
- Tänu flash mälule on võimalik kaasaegseid mikrokontrollereid (edaspidi MC) programeerida mitmeid kordi uuesti, samas kui vanemaid MC oli võimalik programeerida ainult korra ja kui programm ei töödanud tuli võtta järgmine MC.
- Kui MC peaks muutuma nii kuumaks, et seda on näpuga tunda, siis ilmselt on see MC kutu.
- Now with a micro, the most basic pin function is GPIO - general purpose input/output. These GPIO pins can be configured as an input or an output.
- There are thousands of different micros out there, but 5V (five volts) is the typical VCC. 3.3V is also typical but you'll also see 2.8V and 1.8V VCCs on more exotic micros. For now, just worry about 5V and GND. Põhimõtteliselt siis peaks saama MC jooksutada USB pealt, sest sealtki tuleb 5V kenasti kätte. Esialgu aga ilmselt piirdume patareiga. Esialgu.
- Otse "seinaklotsist" (pingeadapterist) tulev pinge ei pruugi üldse reaalselt vastata spec's väärtustele, olles mõne voldi võrra kõrgem, kui lubatud. Et sellega oma MC juhtida, peab vahele panema veel regulaatori.
- Pinge täielikuks silumiseks on vajalikud filtreerimiskondekad.
- Capacitors cannot deliver their stored energy instantaneously. Larger caps (1ouF and 100uF) store more energy, but they react more slowly. The smaller the capacitor, the faster it can deliver its stored energy. If you have a large power outage (power dips for 10-100ms), a big cap (100uF to 1000uF) will help 'hold up' the falling voltage. A smaller cap (0.1uF) will help suppress higher frequency noise and shorter power dips (noise in the 1us to 100us range). Therefore, 0.1uF caps are located near the microcontroller to help with short bursts, where 100uF and 10uF caps are used on the power rails.
- 100uF/25V tähendab, et 100 mikrofaradine kondekas peab vastu 25 voldisele pingele, aga reeglina peaks kondeka pingetaluvus olema 50% kõrgem, kui reaalne kasutatav pinge. St., et sellise kondeka võib ühendada umbes 12V pingega. Kondekad pole eriti kindlad elemendid.
- Lisaks on vaja kaitsedioodi (nt. lüliti ette), mis ei luba voolul hakata valepidi käima. Nt. kui ühendada GND ja VCC vastupidi...see oleks paha. Samas kaitsediood ei lase sel juhul ülejäänud süsteemi käima.
- VooluLED'i ette/taha käib loomulikult takistus, mille suurus arvutatakse Ohmi seadusest, arvestades LEDi voolutaluvust ja kasutatava pinget. Ilma takistuseta tekiks LEDis lühis ja ta põleks lihtsalt maha.
- If you turn on your system and the Power LED does not turn on, immediately turn off the system and check your wiring.
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