Newbe Dev Stack

Answer : You can always use the analog pins for digital writing. digitalRead() works on all pins. It will just round the analog value received and present it to you. If analogRead(A0) is greater than or equal to 512, digitalRead(A0) will be 1, else 0. digitalWrite() works on all pins, with allowed parameter 0 or 1. digitalWrite(A0,0) is the same as analogWrite(A0,0) , and digitalWrite(A0,1) is the same as analogWrite(A0,255) analogRead() works only on analog pins. It can take any value between 0 and 1023. analogWrite() works on all analog pins and all digital PWM pins. You can supply it any value between 0 and 255. The analog pins let you read/write analog values - basically, instead of giving out a voltage of 0 or 5 (as with digital), they can give a range of voltages between 0 and 5 (both as input and output). Note that the voltage during analog output is only the observed voltage with a multimeter. In reality, the analog pins send pulses of 0V and 5V signals to ...

Answer : To answer Tyilo's specific questions: analogRead(5) and digitalRead(5) will read from two different places. The former will read from analog channel 5 or A5 and the latter will read from pin 5 which happens to be a digital pin. So yes, if you want to read an analog pin with digitalRead you should be using A5 . Why? analogRead requires a channel number internally but it will allow you to give it a pin number too. If you do give it a pin number it will convert it to its corresponding channel number. As far as I can tell analogRead is the only function which uses a channel number internally, is the only one to allow a channel number, and is the only function with this undocumented pin-to-channel conversion. To understand this let's start off with some examples. If you want to use analogRead on the first analog pin A0 you can do analogRead(0) which uses the channel number or analogRead(A0) which uses the pin number. If you were to use the pin number ...