/* | |
* FreeRTOS Kernel V10.3.0 | |
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*/ | |
/* | |
* This is a mini co-routine demo for the Rowley CrossFire LM3S102 development | |
* board. It makes use of the boards tri-colour LED and analogue input. | |
* | |
* Four co-routines are created - an 'I2C' co-routine and three 'flash' | |
* co-routines. | |
* | |
* The I2C co-routine triggers an ADC conversion then blocks on a queue to | |
* wait for the conversion result - which it receives on the queue directly | |
* from the I2C interrupt service routine. The conversion result is then | |
* scalled to a delay period. The I2C interrupt then wakes each of the | |
* flash co-routines before itself delaying for the calculated period and | |
* then repeating the whole process. | |
* | |
* When woken by the I2C co-routine the flash co-routines each block for | |
* a given period, illuminate an LED for a fixed period, then go back to | |
* sleep to wait for the next cycle. The uxIndex parameter of the flash | |
* co-routines is used to ensure that each flashes a different LED, and that | |
* the delay periods are such that the LED's get flashed in sequence. | |
*/ | |
/* Scheduler include files. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
#include "queue.h" | |
#include "croutine.h" | |
/* Demo application include files. */ | |
#include "partest.h" | |
/* Library include files. */ | |
#include "DriverLib.h" | |
/* States of the I2C master interface. */ | |
#define mainI2C_IDLE 0 | |
#define mainI2C_READ_1 1 | |
#define mainI2C_READ_2 2 | |
#define mainI2C_READ_DONE 3 | |
#define mainZERO_LENGTH 0 | |
/* Address of the A2D IC on the CrossFire board. */ | |
#define mainI2CAddress 0x4D | |
/* The queue used to send data from the I2C ISR to the co-routine should never | |
contain more than one item as the same co-routine is used to trigger the I2C | |
activity. */ | |
#define mainQUEUE_LENGTH 1 | |
/* The CrossFire board contains a tri-colour LED. */ | |
#define mainNUM_LEDs 3 | |
/* The I2C co-routine has a higher priority than the flash co-routines. This | |
is not really necessary as when the I2C co-routine is active the other | |
co-routines are delaying. */ | |
#define mainI2c_CO_ROUTINE_PRIORITY 1 | |
/* The current state of the I2C master. */ | |
static volatile unsigned portBASE_TYPE uxState = mainI2C_IDLE; | |
/* The delay period derived from the A2D value. */ | |
static volatile portBASE_TYPE uxDelay = 250; | |
/* The queue used to communicate between the I2C interrupt and the I2C | |
co-routine. */ | |
static QueueHandle_t xADCQueue; | |
/* The queue used to synchronise the flash co-routines. */ | |
static QueueHandle_t xDelayQueue; | |
/* | |
* Sets up the PLL, I2C and GPIO used by the demo. | |
*/ | |
static void prvSetupHardware( void ); | |
/* The co-routines as described at the top of the file. */ | |
static void vI2CCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex ); | |
static void vFlashCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex ); | |
/*-----------------------------------------------------------*/ | |
int main( void ) | |
{ | |
unsigned portBASE_TYPE uxCoRoutine; | |
/* Setup all the hardware used by this demo. */ | |
prvSetupHardware(); | |
/* Create the queue used to communicate between the ISR and I2C co-routine. | |
This can only ever contain one value. */ | |
xADCQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( TickType_t ) ); | |
/* Create the queue used to synchronise the flash co-routines. The queue | |
is used to trigger three tasks, but is for synchronisation only and does | |
not pass any data. It therefore has three position each of zero length. */ | |
xDelayQueue = xQueueCreate( mainNUM_LEDs, mainZERO_LENGTH ); | |
/* Create the co-routine that initiates the i2c. */ | |
xCoRoutineCreate( vI2CCoRoutine, mainI2c_CO_ROUTINE_PRIORITY, 0 ); | |
/* Create the flash co-routines. */ | |
for( uxCoRoutine = 0; uxCoRoutine < mainNUM_LEDs; uxCoRoutine++ ) | |
{ | |
xCoRoutineCreate( vFlashCoRoutine, tskIDLE_PRIORITY, uxCoRoutine ); | |
} | |
/* Start the scheduler. From this point on the co-routines should | |
execute. */ | |
vTaskStartScheduler(); | |
/* Should not get here unless we did not have enough memory to start the | |
scheduler. */ | |
for( ;; ); | |
return 0; | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvSetupHardware( void ) | |
{ | |
/* Setup the PLL. */ | |
SysCtlClockSet( SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_6MHZ ); | |
/* Enable the I2C used to read the pot. */ | |
SysCtlPeripheralEnable( SYSCTL_PERIPH_I2C ); | |
SysCtlPeripheralEnable( SYSCTL_PERIPH_GPIOB ); | |
GPIOPinTypeI2C( GPIO_PORTB_BASE, GPIO_PIN_2 | GPIO_PIN_3 ); | |
/* Initialize the I2C master. */ | |
I2CMasterInit( I2C_MASTER_BASE, pdFALSE ); | |
/* Enable the I2C master interrupt. */ | |
I2CMasterIntEnable( I2C_MASTER_BASE ); | |
IntEnable( INT_I2C ); | |
/* Initialise the hardware used to talk to the LED's. */ | |
vParTestInitialise(); | |
} | |
/*-----------------------------------------------------------*/ | |
static void vI2CCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex ) | |
{ | |
TickType_t xADCResult; | |
static portBASE_TYPE xResult = 0, xMilliSecs, xLED; | |
crSTART( xHandle ); | |
for( ;; ) | |
{ | |
/* Start the I2C off to read the ADC. */ | |
uxState = mainI2C_READ_1; | |
I2CMasterSlaveAddrSet( I2C_MASTER_BASE, mainI2CAddress, pdTRUE ); | |
I2CMasterControl( I2C_MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START ); | |
/* Wait to receive the conversion result. */ | |
crQUEUE_RECEIVE( xHandle, xADCQueue, &xADCResult, portMAX_DELAY, &xResult ); | |
/* Scale the result to give a useful range of values for a visual | |
demo. */ | |
xADCResult >>= 2; | |
xMilliSecs = xADCResult / portTICK_PERIOD_MS; | |
/* The delay is split between the four co-routines so they remain in | |
synch. */ | |
uxDelay = xMilliSecs / ( mainNUM_LEDs + 1 ); | |
/* Trigger each of the flash co-routines. */ | |
for( xLED = 0; xLED < mainNUM_LEDs; xLED++ ) | |
{ | |
crQUEUE_SEND( xHandle, xDelayQueue, &xLED, 0, &xResult ); | |
} | |
/* Wait for the full delay time then start again. This delay is long | |
enough to ensure the flash co-routines have done their thing and gone | |
back to sleep. */ | |
crDELAY( xHandle, xMilliSecs ); | |
} | |
crEND(); | |
} | |
/*-----------------------------------------------------------*/ | |
static void vFlashCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex ) | |
{ | |
portBASE_TYPE xResult, xNothing; | |
crSTART( xHandle ); | |
for( ;; ) | |
{ | |
/* Wait for start of next round. */ | |
crQUEUE_RECEIVE( xHandle, xDelayQueue, &xNothing, portMAX_DELAY, &xResult ); | |
/* Wait until it is this co-routines turn to flash. */ | |
crDELAY( xHandle, uxDelay * uxIndex ); | |
/* Turn on the LED for a fixed period. */ | |
vParTestSetLED( uxIndex, pdTRUE ); | |
crDELAY( xHandle, uxDelay ); | |
vParTestSetLED( uxIndex, pdFALSE ); | |
/* Go back and wait for the next round. */ | |
} | |
crEND(); | |
} | |
/*-----------------------------------------------------------*/ | |
void vI2C_ISR(void) | |
{ | |
static TickType_t xReading; | |
/* Clear the interrupt. */ | |
I2CMasterIntClear( I2C_MASTER_BASE ); | |
/* Determine what to do based on the current uxState. */ | |
switch (uxState) | |
{ | |
case mainI2C_IDLE: break; | |
case mainI2C_READ_1: /* Read ADC result high byte. */ | |
xReading = I2CMasterDataGet( I2C_MASTER_BASE ); | |
xReading <<= 8; | |
/* Continue the burst read. */ | |
I2CMasterControl( I2C_MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_CONT ); | |
uxState = mainI2C_READ_2; | |
break; | |
case mainI2C_READ_2: /* Read ADC result low byte. */ | |
xReading |= I2CMasterDataGet( I2C_MASTER_BASE ); | |
/* Finish the burst read. */ | |
I2CMasterControl( I2C_MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH ); | |
uxState = mainI2C_READ_DONE; | |
break; | |
case mainI2C_READ_DONE: /* Complete. */ | |
I2CMasterDataGet( I2C_MASTER_BASE ); | |
uxState = mainI2C_IDLE; | |
/* Send the result to the co-routine. */ | |
crQUEUE_SEND_FROM_ISR( xADCQueue, &xReading, pdFALSE ); | |
break; | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
void vApplicationIdleHook( void ) | |
{ | |
for( ;; ) | |
{ | |
vCoRoutineSchedule(); | |
} | |
} | |