Veja uma fascinante foto de um olho com seus mínimos detalhes. A foto acima é meio apavorante, não é?
Ver o olho humano com tantos detalhes nos faz pensar que tem algo de muito “esquisito” com ele. Mas essa aparência é devida a complexidade desse órgão da visão. São músculos, nervos, veias sanguíneas, fibras, etc, que se ligam para permitir a rotação do globo ocular e a focalização das imagens. O interior do olho é preenchido por um fluido que, juntamente com a camada de tecido externa, mantém sua forma arredondada, protegendo o olho contra forças mecânicas exteriores. Da mesma forma, uma membrana mais externa ainda, denominada de conjuntiva, recobre a superfície interior das pálpebras e a superfície anterior do globo ocular, produzindo muco para lubrificação, evitando o ressecamento do olho.
Como enxergamos O nervo óptico, composto por um conglomerado de fibras nervosas que nascem na retina, [é o responsável pela conexão entre o globo ocular e o sistema nervoso central. Code, circuits, & construction. A stepper motor is a motor controlled by a series of electromagnetic coils.
The center shaft has a series of magnets mounted on it, and the coils surrounding the shaft are alternately given current or not, creating magnetic fields which repulse or attract the magnets on the shaft, causing the motor to rotate. This design allows for very precise control of the motor: by proper pulsing, it can be turned in very accurate steps of set degree increments (for example, two-degree increments, half-degree increments, etc.). They are used in printers, disk drives, and other devices where precise positioning of the motor is necessary. There are two basic types of stepper motors, unipolar steppers and bipolar steppers. Unipolar Stepper Motors The unipolar stepper motor has five or six wires and four coils (actually two coils divided by center connections on each coil). Bipolar stepper motors The bipolar stepper motor usually has four wires coming out of it. Two-Wire Control BX-24 code: PicBasic Pro code:
AC Arduino dimming circuit. THANKS TO EVERYONE WHO COMMENTED, I LEARNED A LOT I am not an engineer, just an experimenter and hacker and prototyper etc, so, thanks to people who know a lot more than I do, I learned that this is not safe to use ------------------------------------ Have you ever wondered how you can use a remote control to dim your own lights, to control a window fan, or to regulate the heater?
Here's a simple circuit using Arduino that makes this possible! It uses ONLY two electrical components. This is recommended for someone who has some experience with Arduino and electronics. As with anything that uses AC wall power, this could be dangerous if done hastily. Done carefully, it could also be really simple and fun. DIY Amp Hour Meter - Arduino. I've changed the resistor values of the voltage divider to get a better impedence match with the Arduino A/D.
Ben from Pololu says: The ADC on an AVR can't very accurately measure signals with a high output impedance, and your voltage divider definitely counts as high-impedance. From the ATmega328P datasheet: The ADC is optimized for analog signals with an output impedance of approximately 10 kΩ or less. If such a source is used, the sampling time will be negligible. I think you'll have better results if you make your voltage divider resistors smaller, such as 10k and 5k, though this would waste 10 times more power (maybe 1.6 mW for your current configuration vs 17 mW for the new one). The Arduino can accept up to 5v on a analog input. The code to read that value is as follows: batteryVoltage = pinVoltage * ratio; // Use the ratio calculated for the voltage divider // to calculate the battery voltage I have 4 possible nominal battery bank voltages.
Solving for R1 R1 = ((R2*Vin)/Vout)-R2. Arduino Motor Shield Tutorial. AC-board-schematic.