Arduino Chibios/RT Uno example with 10 tasks
Setting up Chibios for Arduino
Setting up the Arduino environment to use Chibios is very simple. Just follow these steps:
- Download the library from http://rtoslibs.googlecode.com. As of Mar 2013, the file you want is http://rtoslibs.googlecode.com/files/ChibiOS20130208.zip This archive contains the libraries for both the AVR and ARM processors.
- Extract the AVR or ARM library as needed, and copy it into the /LIB directory of your Arduino installation.
This program does not approach the limit of processor time. It spends most of its time in time delays. This is even the case when the delay values are run down to very low values.
The limiting factor in this example is RAM space. Each thread requires a certain amount of ram to store the thread state, and with only 2048 bytes of ram available thread overhead can exceed the RAM requirements of the application itself.
// A more complex demo of 10 threads
// LED blink threads, print thread, and idle loop
// This program creates 10 threads, nine of which
// blink an LED in a regular pattern, and three
// of which blink an LED in Morse Code
#include <ChibiOS.h>
#include <util/atomic.h>
volatile uint32_t count = 0;
//------------------------------------------------------------------------------
// thread 1 - high priority for blinking LED
// 64 byte stack beyond task switch and interrupt needs
#define DOTLENGTH 90 // All timing is based on this time. Lower for faster code.
static WORKING_AREA(waThread13, 52);
static msg_t Thread13(void *arg)
{
int outpin = 13;
char message[] = "SOS The moon rover has broken down and I am stuck in the trash can in the garden shed.";
pinMode(outpin, OUTPUT);
while(1)
{
chThdSleepMilliseconds( 3000 ); // three second delay before (and between).
for (byte j=0; j<sizeof(message); j++)
{
send(message[j], outpin); // Send each character in the message.
}
}
}
static WORKING_AREA(waThread14, 52);
static msg_t Thread14(void *arg)
{
int outpin = 14;
char message[] = "SOS The moon rover has broken down and I am stuck in the trash can in the garden shed.";
pinMode(outpin, OUTPUT);
while(1)
{
chThdSleepMilliseconds( 1000 ); // three second delay before (and between).
for (byte j=0; j<sizeof(message); j++)
{
send(message[j], outpin); // Send each character in the message.
}
}
}
//------------------------------------------------------------------------------
// thread 15 - high priority for blinking LED
// 64 byte stack beyond task switch and interrupt needs
static WORKING_AREA(waThread15, 52);
static msg_t Thread15(void *arg)
{
int outpin = 15;
pinMode(outpin, OUTPUT);
char message[] = "now is the time for all good men to come to the aid of their women";
while(1)
{
chThdSleepMilliseconds( 2000 ); // three second delay before (and between).
for (byte j=0; j<sizeof(message); j++)
{
send(message[j], outpin); // Send each character in the message.
}
}
}
void dot(int pin) {
// Make a dot signal
digitalWrite(pin, HIGH);
chThdSleepMilliseconds(DOTLENGTH);
digitalWrite(pin, LOW);
chThdSleepMilliseconds(DOTLENGTH);
}
void dash(int pin) {
// Make a dash signal
digitalWrite(pin, HIGH);
chThdSleepMilliseconds(3*DOTLENGTH);
digitalWrite(pin, LOW);
chThdSleepMilliseconds(DOTLENGTH);
}
void letterBreak() {
// The break between letters is 3x(dot length).
// One dot length comes automatically at the end of
// the previous dot or dash, so 2 more are needed.
chThdSleepMilliseconds(2*DOTLENGTH);
}
void wordBreak() {
// The break between words is 4x(dot length).
// Three come for free since a letter just ended,
// so 4 more are needed.
chThdSleepMilliseconds(4*DOTLENGTH);
}
void send(char letter, int pin) {
// Sends the given letter to the output
switch (letter) {
case 'A':
case 'a': dot( pin ); dash( pin ); break;
case 'B':
case 'b': dash( pin ); dot( pin ); dot( pin ); dot( pin ); break;
case 'C':
case 'c': dash( pin ); dot( pin ); dash( pin ); dot( pin ); break;
case 'D':
case 'd': dash( pin ); dot( pin ); dot( pin ); break;
case 'E':
case 'e': dot( pin ); break;
case 'F':
case 'f': dot( pin ); dot( pin ); dash( pin ); dot( pin ); break;
case 'G':
case 'g': dash( pin ); dash( pin ); dot( pin ); break;
case 'H':
case 'h': dot( pin ); dot( pin ); dot( pin ); dot( pin ); break;
case 'I':
case 'i': dot( pin ); dot( pin ); break;
case 'J':
case 'j': dot( pin ); dash( pin ); dash( pin ); dash( pin ); break;
case 'K':
case 'k': dash( pin ); dot( pin ); dash( pin ); break;
case 'L':
case 'l': dot( pin ); dash( pin ); dot( pin ); dot( pin ); break;
case 'M':
case 'm': dash( pin ); dash( pin ); break;
case 'N':
case 'n': dash( pin ); dot( pin ); break;
case 'O':
case 'o': dash( pin ); dash( pin ); dash( pin ); break;
case 'P':
case 'p': dot( pin ); dash( pin ); dash( pin ); dot( pin ); break;
case 'Q':
case 'q': dash( pin ); dash( pin ); dot( pin ); dash( pin ); break;
case 'R':
case 'r': dot( pin ); dash( pin ); dot( pin ); break;
case 'S':
case 's': dot( pin ); dot( pin ); dot( pin ); break;
case 'T':
case 't': dash( pin ); break;
case 'U':
case 'u': dot( pin ); dot( pin ); dash( pin ); break;
case 'V':
case 'v': dot( pin ); dot( pin ); dot( pin ); dash( pin ); break;
case 'W':
case 'w': dot( pin ); dash( pin ); dash( pin ); break;
case 'X':
case 'x': dash( pin ); dot( pin ); dot( pin ); dash( pin ); break;
case 'Y':
case 'y': dash( pin ); dot( pin ); dash( pin ); dash( pin ); break;
case 'Z':
case 'z': dash( pin ); dash( pin ); dot( pin ); dot( pin ); break;
case '0': dash( pin ); dash( pin ); dash( pin ); dash( pin ); dash( pin ); break;
case '1': dot( pin ); dash( pin ); dash( pin ); dash( pin ); dash( pin ); break;
case '2': dot( pin ); dot( pin ); dash( pin ); dash( pin ); dash( pin ); break;
case '3': dot( pin ); dot( pin ); dot( pin ); dash( pin ); dash( pin ); break;
case '4': dot( pin ); dot( pin ); dot( pin ); dot( pin ); dash( pin ); break;
case '5': dot( pin ); dot( pin ); dot( pin ); dot( pin ); dot( pin ); break;
case '6': dash( pin ); dot( pin ); dot( pin ); dot( pin ); dot( pin ); break;
case '7': dash( pin ); dash( pin ); dot( pin ); dot( pin ); dot( pin ); break;
case '8': dash( pin ); dash( pin ); dash( pin ); dot( pin ); dot( pin ); break;
case '9': dash( pin ); dash( pin ); dash( pin ); dash( pin ); dot( pin ); break;
case ',': dash( pin ); dash( pin ); dot( pin ); dot( pin ); dash( pin ); dash( pin ); break;
case '.': dot( pin ); dash( pin ); dot( pin ); dash( pin ); dot( pin ); dash( pin ); break;
case '?': dot( pin ); dot( pin ); dash( pin ); dash( pin ); dot( pin ); dot( pin ); break;
case ';': dash( pin ); dot( pin ); dash( pin ); dot( pin ); dash( pin ); dot( pin ); break;
case '\'': dash( pin ); dash( pin ); dash( pin ); dot( pin ); dot( pin ); dot( pin ); break;
case '-': dash( pin ); dot( pin ); dot( pin ); dot( pin ); dot( pin ); dash( pin ); break;
case '/': dash( pin ); dot( pin ); dot( pin ); dash( pin ); dot( pin ); break;
case '(':
case ')': dash( pin ); dot( pin ); dash( pin ); dash( pin ); dot( pin ); dash( pin ); break;
case '_': dot( pin ); dot( pin ); dash( pin ); dash( pin ); dot( pin ); dash( pin ); dash( pin ); break;
case ' ': wordBreak(); break;
}
letterBreak();
}
//------------------------------------------------------------------------------
// thread 1 - print idle loop count every second
// 200 byte stack beyond task switch and interrupt needs
static WORKING_AREA(waThread1, 200);
static msg_t Thread1(void *arg) {
Serial.begin(9600);
while (TRUE) {
Serial.println(count);
chThdSleepMilliseconds(1000);
}
return 0;
}
//------------------------------------------------------------------------------
// thread 2 - high priority for blinking LED
// 64 byte stack beyond task switch and interrupt needs
static WORKING_AREA(waThread2, 8);
static msg_t Thread2(void *arg)
{
int outpin = 2;
pinMode(outpin, OUTPUT);
while(1)
{
// Make a dot signal
digitalWrite(outpin, HIGH);
chThdSleepMilliseconds( 100 );
digitalWrite(outpin, LOW);
chThdSleepMilliseconds( 100 );
}
}
//------------------------------------------------------------------------------
// thread 3 - high priority for blinking LED
// 64 byte stack beyond task switch and interrupt needs
static WORKING_AREA(waThread3, 8);
static msg_t Thread3(void *arg)
{
int outpin = 3;
pinMode(outpin, OUTPUT);
while(1)
{
// Make a dot signal
digitalWrite(outpin, HIGH);
chThdSleepMilliseconds( 110 );
digitalWrite(outpin, LOW);
chThdSleepMilliseconds( 790 );
}
}
//------------------------------------------------------------------------------
// thread 4 - high priority for blinking LED
// 64 byte stack beyond task switch and interrupt needs
static WORKING_AREA(waThread4, 8);
static msg_t Thread4(void *arg)
{
int outpin = 4;
pinMode(outpin, OUTPUT);
while(1)
{
// Make a dot signal
digitalWrite(outpin, HIGH);
chThdSleepMilliseconds( 1220 );
digitalWrite(outpin, LOW);
chThdSleepMilliseconds( 800 );
}
}
//------------------------------------------------------------------------------
// thread 5 - high priority for blinking LED
// 64 byte stack beyond task switch and interrupt needs
static WORKING_AREA(waThread5, 8);
static msg_t Thread5(void *arg)
{
int outpin = 5;
pinMode(outpin, OUTPUT);
while(1)
{
// Make a dot signal
digitalWrite(outpin, HIGH);
chThdSleepMilliseconds( 830 );
digitalWrite(outpin, LOW);
chThdSleepMilliseconds( 270 );
}
}
//------------------------------------------------------------------------------
// thread 6 - high priority for blinking LED
// 64 byte stack beyond task switch and interrupt needs
static WORKING_AREA(waThread6, 8);
static msg_t Thread6(void *arg)
{
int outpin = 6;
pinMode(outpin, OUTPUT);
while(1)
{
// Make a dot signal
digitalWrite(outpin, HIGH);
chThdSleepMilliseconds( 340 );
digitalWrite(outpin, LOW);
chThdSleepMilliseconds( 60 );
}
}
//------------------------------------------------------------------------------
// thread 7 - high priority for blinking LED
// 64 byte stack beyond task switch and interrupt needs
static WORKING_AREA(waThread7, 8);
static msg_t Thread7(void *arg)
{
int outpin = 7;
pinMode(outpin, OUTPUT);
char message[] = "This is a test, this is only a test";
while(1)
{
chThdSleepMilliseconds( 2000 ); // three second delay before (and between).
for (byte j=0; j<sizeof(message); j++)
{
send(message[j], outpin); // Send each character in the message.
}
}
}
//------------------------------------------------------------------------------
void setup() {
// initialize ChibiOS with interrupts disabled
// ChibiOS will enable interrupts
cli();
halInit();
chSysInit();
// start print thread
chThdCreateStatic(waThread1, sizeof(waThread1),
NORMALPRIO + 1, Thread1, NULL);
// start blink thread
chThdCreateStatic(waThread2, sizeof(waThread2),
NORMALPRIO + 1, Thread2, NULL);
// start blink thread
chThdCreateStatic(waThread3, sizeof(waThread3),
NORMALPRIO + 2, Thread3, NULL);
// start blink thread
chThdCreateStatic(waThread4, sizeof(waThread4),
NORMALPRIO + 2, Thread4, NULL);
// start blink thread
chThdCreateStatic(waThread5, sizeof(waThread5),
NORMALPRIO + 2, Thread5, NULL);
// start blink thread
chThdCreateStatic(waThread6, sizeof(waThread6),
NORMALPRIO + 2, Thread6, NULL);
// start blink thread
chThdCreateStatic(waThread7, sizeof(waThread7),
NORMALPRIO + 2, Thread7, NULL);
----------------------------------
// start morse code thread
chThdCreateStatic(waThread13, sizeof(waThread13),
NORMALPRIO + 2, Thread13, NULL);
// start morse code thread
chThdCreateStatic(waThread14, sizeof(waThread14),
NORMALPRIO + 2, Thread14, NULL);
// start morse code thread
chThdCreateStatic(waThread15, sizeof(waThread15),
NORMALPRIO + 2, Thread15, NULL);
}
//------------------------------------------------------------------------------
// idle loop runs at NORMALPRIO
void loop() {
// must insure increment is atomic
// in case of context switch for print
ATOMIC_BLOCK(ATOMIC_FORCEON) {
count++;
}
}