View Kit List. PIC Tutorials categorized view. Core Tutorials. PIC Tutorials Table of contents. Introduction To Microcontrollers. Timer Module VS Delay. Share this course page! Support This work? This tutorial will guide you through the process of creating your first Microchip PIC microcontroller based circuit. All the software used in this tutorial is absolutely free. All you need is a simple JDM programmer read on for detials , and you are good to go!
Our circuit needs power supply. Connect the transformator to your circuit and turn the switch on. Type the following code into the file you have just created:. A pin state can either be 0, which means an output, or 1, which means an input.
We define all the port pins as outputs, and hence the 0x00 value. The purpose of this loop is to create a delay between the time the LED turns on, and when it turns off. This is not an optimal way to create a delay, but it will suffice for now.
Before going to build a PIC microcontroller project, we must become aware of developing a basic microcontroller like based project. Once you get the idea, this controller based project building becomes easy, so let us look at the basic steps to build a PIC microcontroller based project. Before going to program the PIC microcontroller, first we have to select the right project that you are going program the microcontroller. As of now, consider the LEDs flash light system. The LEDs flashlight uses a set of light emitting diodes, and these are advanced to the traditional incandescent lights which consumes more energy and have very less life time.
The LED lights on the other hand, consume less energy and have longer life. It is a 40 pin microcontroller. The Crystal interfaced to the input pins of the microcontroller provides accurate clock signals at the crystal frequency. Two capacitors are connected to the crystal oscillator with range of 20pf to 40pf which is used to stabilize the clock signals.
At some times, the PIC microcontroller goes to block state or missing time calculation,at that time we need to reset the microcontroller. If a microcontroller is reset for 3sec time delay, 10k resistor and 10uf capacitor are connected to the respective pins. The 5v DC supply is given to the 11 pin of the microcontroller which drives the circuit.
The crystal is connected to the 13 and 14 pins of the microcontroller. The reset circuit is interfaced at 1 pins of the microcontroller. This circuit is designed with the help of Proteus software. The Proteus is a circuit designing software that contains a database of components, which we can use to build the circuit. After all configuration bits have been set, click the "Generate Source Code to Output" button at the bottom of the panel.
The panel will now switch to the Output tab. Clean and build the project again by clicking the broom and hammer icon. Ensure the build was successful. Also check to make sure there was no errors in the output If everything has worked move on to the next step. If there are errors or warnings fix them before moving on. The next step is to start programming; however, before we get to the application code we must program the system code.
The system code are the low level functions such as configuring the oscillator and basic delay functions. Determining Settings Before we can program the settings, we must choose what speed we would like to run at. If you are using the internal oscillator then use the settings relating to INTIO1 On the next page or two you will find a schematic drawing of the oscillator similar to the one shown. It is helpful to trace the signal on this drawing to ensure the correct speed is being selected.
The next step is to program these settings to the MCU. This is done by setting registers. IDLEN -- used to control the action of the sleep command. Can be left as default.
IRCF -- Oscillator selection. Remove the comments in that function. To set the bits of a register type in all caps the register name, followed by the lowercase word bits and then a period and the bit name. To set the bits follow that with an equal sign.
Lastly end the line with a semi-colon. See below for an example of a finished ConfigureOscillator function. This however is not a function in the standard library, and will need to be programmed by you. For this implementation there will be a loop which will hold the processor until the given time has passed. PIC18F microcontrollers need 4 clock cycles to execute one line of assembly code.
Since a for loop will take one instruction each time for the comparison, and two for the operation one for the body of the loop, it will work perfectly. We just need the for loop to loop time per milli-second. In system. The best way to test that everything is set up correctly is to blink an LED light. If the light blinks at the expected rate then everything has been configured correctly.
If you have your LED connected to a different pin, use the appropriate registers and bits. Open main. The function void main void is the main entry point of the program.
When the MCU first powers on it will enter into this function.
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