Serial.print("Temperature for the device 1 (index 0) is: ") ĭigitalWrite(2, HIGH) //Air Pump-1/LD1 is ONĭigitalWrite(2, LOW) //Air Pump-1/LD1 is OFF Sensors.requestTemperatures() // Send the command to get temperaturesįloat tempC = sensors.getTempCByIndex(0) (b) Upload the following non-object based sketch (LD1 is used to simulate relay-K1) into UNO. (Note that I have avoided saying "non-class version" as class is a keyword which we use to create user-defined data type" from which we create objects on which we apply methods to do some works like pump-on/pump-off.) #include "BlinkLib.h"īlinker blinker(LED_BUILTIN) // Blink the built-in LEDīlinker blinker2(9) // Blink the LED on Pin 9ġ(a) Let us create a "non-object version" sketch to operate one-pump/on-sensor setup as per diagram of Fig-1. blink() method repeatedly in loop(), just like the old blink() function but there can be more of them. begin() for each instance in setup(), and calls the. It sets the pin in the declaration of the instance, calls. The test sketch doesn't have to change much. Void Blinker::blink(const unsigned long interval) The BlinkLib.cpp file now contains definitions for whatever instance functions are not defined in the class declaration. For a global instance (defined outside a function) it is not safe to call Arduino functions in the constructor so we add a "begin()" method to be called to do any Arduino calls needed for setup. The "setPin()" functionality can be done in the 'constructor' so we specify the pin when we create each instance. Void blink(const unsigned long interval) Note that now BlinkLib.h needs some definitions from Arduino.h ('byte', 'LOW', 'pinMode'.) so we include Arduino.h at the top. This goes into BlinkLib.h in place of the shared function prototypes. Let's create an object class named 'Blinker'. You can then make multiple 'instances' of the object, each with its own variables. To fix that, we 'encapsulate' the functionality of the library into an 'object'. One problem with the library is that you can only blink one LED because the library only has one set of global variables. Library header: void blink(unsigned long) Move the declaration of 'ledPin' into BlinkLib.cpp. We need a way for setup() to set the pin mode so we create another function in BlinkLib.cpp: void setPin(int pin) We used 'ledPin' in setup() so we left the declaration there, but now BlinkLib.cpp needs the declaration. That leaves you with the next error: BlinkLib.cpp:21:18: error: 'ledPin' was not declared in this scope This will allow the main sketch to see a declaration of "blink". Create a new tab named BlinkLib.h (h for 'header'). This is a good time to create another tab that shares the library declarations with the sketch that uses the library. That's because the main sketch no longer contains a declaration for the blink() function. Now you get the error: sketch_jan05a:13:3: error: 'blink' was not declared in this scope While you're at it, move 'ledState' and 'interval', too. In this case, only the library needs it so move that declaration to the top of BlinkLib.cpp. This is because that declaration didn't get moved to the library. The next error is: BlinkLib.cpp:6:23: error: 'previousMillis' was not declared in this scope Add that line to the top of BlinkLib.cpp and do another Verify. This is because, unlike a '.ino' file '.cpp' files don't getĪutomatically inserted at compile time. The first is: BlinkLib.cpp:3:33: error: 'millis' was not declared in this scope If you try to Verify your sketch now you will find some errors. Now cut the 'blink' function out of the main tab and paste it into the new tab. At the right end of the bar just above the sketch is a little triangle in a square. This sketch does exactly the same thing as before. The next step is to move the guts of the library behavior into a function. set the LED with the ledState of the variable: If (currentMillis - previousMillis >= interval) You can find the full source under File->Examples->02.Digital->BlinkWithoutDelay so I am removing most of the comments for compactness. Since you want your library to blink an LED, let's start with the BlinkWithoutDelay example. When you are first starting out developing a library you can start with a sketch.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |