Project for Driver Development and Resource Sharing Implementation
/*
* Based on AnalogRead_DigitalRead example from: https://github.com/feilipu/Arduino_FreeRTOS_Library
* Modified by: Frederic Pillon
*/
#include
#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"
// If no default pin for user button (USER_BTN) is defined, define it
#ifndef USER_BTN
#define USER_BTN D1
#endif
#define TFT_DC 2
#define TFT_CS 3
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);
// Declare a mutex Semaphore Handle which we will use to manage the Serial Port.
// It will be used to ensure only only one Task is accessing this resource at any time.
SemaphoreHandle_t xSerialSemaphore;
// define two Tasks for DigitalRead & AnalogRead
void TaskDigitalRead( void *pvParameters );
void TaskAnalogRead( void *pvParameters );
// the setup function runs once when you press reset or power the board
void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB, on LEONARDO, MICRO, YUN, and other 32u4 based boards.
}
// Semaphores are useful to stop a Task proceeding, where it should be paused to wait,
// because it is sharing a resource, such as the Serial port.
// Semaphores should only be used whilst the scheduler is running, but we can set it up here.
if ( xSerialSemaphore == NULL ) // Check to confirm that the Serial Semaphore has not already been created.
{
xSerialSemaphore = xSemaphoreCreateMutex(); // Create a mutex semaphore we will use to manage the Serial Port
if ( ( xSerialSemaphore ) != NULL )
xSemaphoreGive( ( xSerialSemaphore ) ); // Make the Serial Port available for use, by "Giving" the Semaphore.
}
// Now set up two Tasks to run independently.
xTaskCreate(
TaskDigitalRead
, (const portCHAR *)"DigitalRead" // A name just for humans
, 128 // This stack size can be checked & adjusted by reading the Stack Highwater
, NULL
, 3 // Priority, with 3 (configMAX_PRIORITIES - 1) being the highest, and 0 being the lowest.
, NULL );
xTaskCreate(
TaskAnalogRead
, (const portCHAR *) "AnalogRead"
, 128 // Stack size
, NULL
, 2 // Priority
, NULL );
// start scheduler
vTaskStartScheduler();
Serial.println("Insufficient RAM");
while(1);
}
void loop()
{
// Empty. Things are done in Tasks.
}
/*--------------------------------------------------*/
/*---------------------- Tasks ---------------------*/
/*--------------------------------------------------*/
void TaskDigitalRead( void *pvParameters __attribute__((unused)) ) // This is a Task.
{
/*
DigitalReadSerial
Reads a digital input on pin defined with USER_BTN, prints the result to the serial monitor
This example code is in the public domain.
*/
// defined USER_BTN digital pin has a pushbutton attached to it. Give it a name:
//uint8_t pushButton = USER_BTN;
// make the pushbutton's pin an input:
//pinMode(pushButton, INPUT);
for (;;) // A Task shall never return or exit.
{
// read the input pin:
int sensorValue1 = analogRead(A1);
// See if we can obtain or "Take" the Serial Semaphore.
// If the semaphore is not available, wait 5 ticks of the Scheduler to see if it becomes free.
if ( xSemaphoreTake( xSerialSemaphore, ( TickType_t ) 5 ) == pdTRUE )
{
// We were able to obtain or "Take" the semaphore and can now access the shared resource.
// We want to have the Serial Port for us alone, as it takes some time to print,
// so we don't want it getting stolen during the middle of a conversion.
// print out the state of the button:
Serial.print("Value 1: ");
tft.setCursor(20, 120);
tft.setTextColor(ILI9341_RED);
tft.setTextSize(3);
tft.println(sensorValue1);
// Serial.println(sensorValue1);
xSemaphoreGive( xSerialSemaphore ); // Now free or "Give" the Serial Port for others.
}
vTaskDelay(500); // one tick delay (15ms) in between reads for stability
}
}
void TaskAnalogRead( void *pvParameters __attribute__((unused)) ) // This is a Task.
{
for (;;)
{
// read the input on analog pin 0:
int sensorValue2 = analogRead(A0);
// See if we can obtain or "Take" the Serial Semaphore.
// If the semaphore is not available, wait 5 ticks of the Scheduler to see if it becomes free.
if ( xSemaphoreTake( xSerialSemaphore, ( TickType_t ) 5 ) == pdTRUE )
{
// We were able to obtain or "Take" the semaphore and can now access the shared resource.
// We want to have the Serial Port for us alone, as it takes some time to print,
// so we don't want it getting stolen during the middle of a conversion.
// print out the value you read:
Serial.print("Value 2: ");
Serial.println(sensorValue2);
xSemaphoreGive( xSerialSemaphore ); // Now free or "Give" the Serial Port for others.
}
vTaskDelay(500); // one tick delay (15ms) in between reads for stability
}
}