/* FreeRTOS V7.5.2 - Copyright (C) 2013 Real Time Engineers Ltd. VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that has become a de facto standard. * * * * Help yourself get started quickly and support the FreeRTOS * * project by purchasing a FreeRTOS tutorial book, reference * * manual, or both from: http://www.FreeRTOS.org/Documentation * * * * Thank you! * * * *************************************************************************** This file is part of the FreeRTOS distribution. FreeRTOS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License (version 2) as published by the Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception. >>! NOTE: The modification to the GPL is included to allow you to distribute >>! a combined work that includes FreeRTOS without being obliged to provide >>! the source code for proprietary components outside of the FreeRTOS >>! kernel. FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Full license text is available from the following link: http://www.freertos.org/a00114.html 1 tab == 4 spaces! *************************************************************************** * * * Having a problem? Start by reading the FAQ "My application does * * not run, what could be wrong?" * * * * http://www.FreeRTOS.org/FAQHelp.html * * * *************************************************************************** http://www.FreeRTOS.org - Documentation, books, training, latest versions, license and Real Time Engineers Ltd. contact details. http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, including FreeRTOS+Trace - an indispensable productivity tool, a DOS compatible FAT file system, and our tiny thread aware UDP/IP stack. http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and middleware. http://www.SafeRTOS.com - High Integrity Systems also provide a safety engineered and independently SIL3 certified version for use in safety and mission critical applications that require provable dependability. 1 tab == 4 spaces! */ /* Changes from V3.0.0 + ISRcode removed. Is now pulled inline to reduce stack-usage. Changes from V3.0.1 */ /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. */ /* Scheduler header files. */ #include "FreeRTOS.h" #include "task.h" #include "queue.h" #include "serial.h" /* Hardware pin definitions. */ #define serTX_PIN bTRC6 #define serRX_PIN bTRC7 /* Bit/register definitions. */ #define serINPUT ( 1 ) #define serOUTPUT ( 0 ) #define serINTERRUPT_ENABLED ( 1 ) /* All ISR's use the PIC18 low priority interrupt. */ #define serLOW_PRIORITY ( 0 ) /*-----------------------------------------------------------*/ /* Queues to interface between comms API and interrupt routines. */ xQueueHandle xRxedChars; xQueueHandle xCharsForTx; portBASE_TYPE xHigherPriorityTaskWoken; /*-----------------------------------------------------------*/ xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned char ucQueueLength ) { unsigned short usSPBRG; /* Create the queues used by the ISR's to interface to tasks. */ xRxedChars = xQueueCreate( ucQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) ); xCharsForTx = xQueueCreate( ucQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) ); portENTER_CRITICAL(); /* Setup the IO pins to enable the USART IO. */ serTX_PIN = serINPUT; // YES really! See datasheet serRX_PIN = serINPUT; /* Set the TX config register. */ TXSTA = 0b00100000; // ||||||||--bit0: TX9D = n/a // |||||||---bit1: TRMT = ReadOnly // ||||||----bit2: BRGH = High speed // |||||-----bit3: SENDB = n/a // ||||------bit4: SYNC = Asynchronous mode // |||-------bit5: TXEN = Transmit enable // ||--------bit6: TX9 = 8-bit transmission // |---------bit7: CSRC = n/a /* Set the Receive config register. */ RCSTA = 0b10010000; // ||||||||--bit0: RX9D = ReadOnly // |||||||---bit1: OERR = ReadOnly // ||||||----bit2: FERR = ReadOnly // |||||-----bit3: ADDEN = n/a // ||||------bit4: CREN = Enable receiver // |||-------bit5: SREN = n/a // ||--------bit6: RX9 = 8-bit reception // |---------bit7: SPEN = Serial port enabled /* Calculate the baud rate generator value. We use low-speed (BRGH=0), the formula is SPBRG = ( ( FOSC / Desired Baud Rate ) / 64 ) - 1 */ usSPBRG = ( ( APROCFREQ / ulWantedBaud ) / 64 ) - 1; if( usSPBRG > 255 ) { SPBRG = 255; } else { SPBRG = usSPBRG; } /* Set the serial interrupts to use the same priority as the tick. */ bTXIP = serLOW_PRIORITY; bRCIP = serLOW_PRIORITY; /* Enable the Rx interrupt now, the Tx interrupt will get enabled when we have data to send. */ bRCIE = serINTERRUPT_ENABLED; portEXIT_CRITICAL(); /* Unlike other ports, this serial code does not allow for more than one com port. We therefore don't return a pointer to a port structure and can instead just return NULL. */ return NULL; } /*-----------------------------------------------------------*/ xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned char ucBufferLength ) { /* This is not implemented in this port. Use xSerialPortInitMinimal() instead. */ return NULL; } /*-----------------------------------------------------------*/ portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime ) { /* Get the next character from the buffer. Return false if no characters are available, or arrive before xBlockTime expires. */ if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) ) { return ( char ) pdTRUE; } return ( char ) pdFALSE; } /*-----------------------------------------------------------*/ portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime ) { /* Return false if after the block time there is no room on the Tx queue. */ if( xQueueSend( xCharsForTx, ( const void * ) &cOutChar, xBlockTime ) != ( char ) pdPASS ) { return pdFAIL; } /* Turn interrupt on - ensure the compiler only generates a single instruction for this. */ bTXIE = serINTERRUPT_ENABLED; return pdPASS; } /*-----------------------------------------------------------*/ void vSerialClose( xComPortHandle xPort ) { /* Not implemented for this port. To implement, turn off the interrupts and delete the memory allocated to the queues. */ }