{"id":71,"date":"2014-09-16T18:21:00","date_gmt":"2014-09-16T18:21:00","guid":{"rendered":"http:\/\/itp.fromjia.com\/?p=71"},"modified":"2014-09-27T02:06:37","modified_gmt":"2014-09-27T02:06:37","slug":"lab-2-inputoutput","status":"publish","type":"post","link":"http:\/\/itp.fromjia.com\/?p=71","title":{"rendered":"Lab 2: Input\/output"},"content":{"rendered":"

For my second lab assignment, I connected a digital input and output<\/em><\/a> circuit and an analog input<\/em><\/a> circuit. (images below) The difference between a digital input and an analog input is that digital input can only sense two states (that’s why it’s also called binary input), on and off, and analog input can read a variable voltage. The range of an analog input is usually between 0 and the maximum voltage that the micro-controller can take. But the range can change depending on the physical context. In these instances, I should use the real range rather than the maximum range of the analog sensor.<\/p>\n

There are various differences in working with digital input versus analog input. For one, an analog input requires an analog-to-digital converter (ADC)<\/em> to read the voltage change and convert it into digital form, because the micro-controller can only read two input values, 0V and 5V. The ADC is built in the Arduino. With a digital input there is not need to convert the voltage.<\/p>\n

Secondly, an analog input is less stable than a digital input. To smooth out the dips and spikes that goes into the circuit when inputing with an analog sensor, I need to decouple the input with a decoupling capacitor.\u00a0<\/em>(Capacitors are used to smooth out signals, by storing energy when the current is passing through and releasing it later.) Also, I should introduce a small delay after reading each sensor, to give the micro-controller time to stabilize before reading the next sensor.<\/p>\n

Digital output is pretty straightforward \u2013 it turns something, such as a LED, on or off.<\/p>\n

Issues:\u00a0<\/b><\/p>\n