arduino:arduino_crash_course:analog_input
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arduino:arduino_crash_course:analog_input [2012/11/06 01:18] – [Night light] mithat | arduino:arduino_crash_course:analog_input [2017/12/06 01:17] – [Night light] mithat | ||
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====== Analog Input ====== | ====== Analog Input ====== | ||
- | As we have seen, an Arduino digital input is one that have one of two states: HIGH or LOW. Most Arduino implementations also permit you to connect an input whose value can be any value between 0 volts and (by default) the power-supply voltage and then convert the input level to an internal digital | + | As we have seen, an Arduino digital input is one that have one of two states: HIGH or LOW. Most Arduino implementations also permit you to connect an input whose value can be any value between 0 volts and (by default) the power-supply voltage, and then convert the input level to an integer |
- | Consult the documentation for your specific Arduino board to detmine | + | Consult the documentation for your specific Arduino board to determine |
===== Night light ===== | ===== Night light ===== | ||
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<WRAP center round tip 60%> | <WRAP center round tip 60%> | ||
- | CdS cells are notoriously tweaky devices. A lot of experimentation with your particular cell will probably be required to see what your circuit is actually doing--quite likely requiring the use of the serial communication to report the ADC values (see [[light_meter|this]] for an example). | + | CdS cells are notoriously tweaky devices. A lot of experimentation with your particular cell will probably be required to see what your circuit is actually doing---quite likely requiring the use of the serial communication to report the ADC values (see [[light_meter|this]] for an example). |
- | There are more reliable and calibrated light-level sensors available that may be a better (but significanly | + | There are more reliable and calibrated light-level sensors available that may be a better (but significantly |
</ | </ | ||
+ | FIXME We need a circuit diagram | ||
- | TODO: | + | <file c NightLight.ino> |
- | - <del>determine default | + | /* |
- | | + | |
- | | + | Turn an LED on when the ambient light is below a certain value. |
+ | */ | ||
+ | |||
+ | const int lightThreshold = 800; // value below which LED turns on | ||
+ | const int inputPin = A0; // use analog | ||
+ | const int ledPin = 13; // connect the LED to pin 13 | ||
+ | |||
+ | int lightLevel = 0; // used to store the input value | ||
+ | |||
+ | void setup() { | ||
+ | | ||
+ | } | ||
+ | |||
+ | void loop() { | ||
+ | | ||
+ | |||
+ | if (lightLevel <= lightThreshold) | ||
+ | digitalWrite(ledPin, | ||
+ | else | ||
+ | digitalWrite(ledPin, | ||
+ | } | ||
+ | </ |
arduino/arduino_crash_course/analog_input.txt · Last modified: 2017/12/06 01:27 by mithat