How to make a program for the Atmel AVR microcontroller using a push button to change the delay that an LED is blinking. The program uses the util/delay.h library and _delay_ms(delayAmount) function. Two delays are used: a 10 millisecond delay and a 100 millisecond delay.
How connect a push button to a microcontroller (make a circucit) and make a program for the Atmel AVR microcontroller using a push button to change the delay that an LED is blinking. The program uses the util/delay.h library and _delay_ms(delayAmount) function. Two delays are used: a 10 millisecond delay and a 100 millisecond delay.
A push button library is created from code written previously to test for button presses and releases and includes software debouncing (debounce). Atmel Studio 6 was used in this video. The library was put into a folder that is used for general includes so including this library would be a simple statement.
All libraries (header files .h) that are created for c or c++ programs must have code in them to make sure they are not compiled more than once. The use of #ifndef #define and #endif is used for this. The #ifndef means if not defined. If a define is in the top portion of the library file to demarkate the file by a special name, then an ifndef can be used to make sure the code in that library is omitted if the define was alreay seen by the compiler.
A function that contains a return is prefixed with a type name. If the function has parameters to be passed in, the parameters will be contained in parenthesis and suffix the function name. For example, a function that returns an integer and has a char parameter would look like this:
The Example in the video was created for the ButtonPress library.
Using the buttonPress library for the Atmel AVR microcontroller. The function is called ButtonPressed and it returns a char for testing if the push button is actually pressed. The parameters are the button number, port where the button is connected, pin of the port where the button is connected, and the confidence level threshold.
To enable interrupts, a library (header file) must be included:
Libraries are used to organize code especially for re-use or when the code gets too long.
This is a brief description of itoa and what library contains this function so it can be invoked. Itoa requires the stdlib.h
Libraries are files containing code that can be used to extend the functionality of a program. In C and C++, these libraries are stored in header files and .C files. The library files are included in the main file using an #include statement.
The header information (generally the code above the main function that include the #define statements and function prototypes), and the functions are stored in the .c file. If desired, all of the code (header and functions) can be stored in the header file.
If a .c file library is created, any global variables that is used in the functions would be located in this .c file rather than the header .h file.
Libraries are files containing code that can be used to extend the functionality of a program. In C and C++, these libraries are stored in header files and .C files. The library files are included in the main file using an #include statement. In this case, only a .h header file will be created.
The header information (generally the code above the main function that include the #define statements and function prototypes), and the functions are stored in the .c file. If desired, all of the code (header and functions) can be stored in the header file.
If a .c file library is created, any global variables that is used in the functions would be located in this .c file rather than the header .h file.
This is a boilerplate code to initialize the ADC for interrupts and including the LCD library so the result can be displayed.
The interrupts library must be included. The OCIE1A (Output Compare Interrupt Enable) is set in the TIMSK1 (Timer mask) register to enable the interrupts for the timer/counter when the ICR (Input Capture Register) is reached. The Global Interrupt is used sei();. When the ICR value is reached, the ISR (Interrupt Service Routine) for the TIMER1_COMPA_vect is called.
The LCD library and initialization is established. The interrupts for the ADC is started and a string is sent to the LCD. This is to get ready for the pressure sensor program. A string is sent to the LCD to create a label called Pressure.
An include file is a library file that contains code that you wish to include in the current program.
On the main menu at the top, click on 'file' and 'new' and 'file'. A dialog box will appear that gives you a list of file types. Select the 'Include File' type and click open. The IDE will provide a default name for the file. When you save the file, just save it as the name you prefer.
Before saving, you will want to save it in a location that is appropriate for the way you will use the file. If this is a project related file, save the file in your project folder. If you will be using this file for many projects, then you will want to save the file in the location where all of the other library files are located.
This is a function that is created for a library to be reused whenever the microcontroller needs to receive data from the UART/USART. The RXC is the Receive Complete Flag and lets us know when the receive is complete so we can get the data in the UDR (UART Data Register). The return type is unsigned char because we want the returned data in the positive realm of 0-255 so it conforms to the ASCII set of characters.
The 0's at the end of each register is used because the microcontroller has two USARTs.
Since we are transmitting data, not return is necessary, but we will need to include a parameter. The parameter will be the data that will be transmitted. The UDRE (USART Data Register Empty) is a flag that tells us when the data register is empty so we can populate the UDR (USART Data Register). When it is ready, we can assign the data to the UDR register. The following code is for microcontroller with more than one USART/UART and uses the first one (the 0's at the end of the registers):
Include files can be saved in a location to be only for the particular project, or located in a folder on the computer for accessing for any project. In this case, I show how to locate the header file so you can access it from any project in the Atmel Studio 6.
The section of the UART/USART initialization for determining the baud rate had an error. The error pertained to first not containing the product of 16 and baud so the F_CPU is not divided by the 16 before the 16 is multiplied by the baud. The second problem was that the letter 'L' was not added after the 16. The L, in the C programming language informs the compiler that the 16 is a long integer.
The section of the UART/USART initialization for determining the baud rate had an error. The error pertained to first not containing the product of 16 and baud so the F_CPU is not divided by the 16 before the 16 is multiplied by the baud. The second problem was that the letter 'L' was not added after the 16. The L, in the C programming language informs the compiler that the 16 is a long integer.
Once you click on the add tool within the schematic editor, a full list of the libraries will be shown in a dialog box. If nothing appears, or if a library is missing, go to the main window and right click the main libraries and select use all, or go to the specific library you want to use and right click on that library and click use.
There is a very broad variety of parts in the library. You will need to drill down to the part you need. You can also use the search.
Once you pick on a part, it will sow the part on the screen and you will need to place the part somewhere on the screen. It will allow you to place this part to many places if you wish. Press escape to stop placing the part, or click on the move tool.
The library dialog box will appear again is the escape key was pressed. If you don't need another part, just click on cancel.
Some parts will allow you to move specific sub portions of the part.
to move many parts at once, you will need to use the group tool. You can draw a rectangle around the parts, or click a polygon around the parts to be more precise in the selecting. Then you need to right click and select move group. If move group is not an option, you will need to click on move, then escape and right click again and the move group will be available.