UART1 buffered serial driver, requires RTOS
Dependents: Serial_interrupts_buffered HARP2 HARP3
Buffered serial UART1 - Setup to work with UART1 (p13,p14)
Uses RTOS to block current thread.
Reference: http://mbed.org/users/tylerjw/notebook/buffered-serial-with-rtos/
Diff: buffered_serial.cpp
- Revision:
- 0:707b9f3904dd
- Child:
- 1:eabb26ce183b
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/buffered_serial.cpp Mon Dec 10 23:42:38 2012 +0000 @@ -0,0 +1,108 @@ +#include "buffered_serial.h" + +BufferedSerial::BufferedSerial(PinName tx, PinName rx) : Serial(tx,rx), led1(LED1), led2(LED2), rx_sem(0), tx_sem(0) +{ + tx_in=0; + tx_out=0; + rx_in=0; + rx_out=0; + + device_irqn = UART1_IRQn; + + // attach the interrupts + Serial::attach(this, &BufferedSerial::Rx_interrupt, Serial::RxIrq); + Serial::attach(this, &BufferedSerial::Tx_interrupt, Serial::TxIrq); +} + +// Copy tx line buffer to large tx buffer for tx interrupt routine +void BufferedSerial::send_line(char *c) +{ + int i; + char temp_char; + bool empty; + i = 0; + strncpy(tx_line,c,LINE_SIZE); + // Start Critical Section - don't interrupt while changing global buffer variables + NVIC_DisableIRQ(device_irqn); + empty = (tx_in == tx_out); + while ((i==0) || (tx_line[i-1] != '\n')) { + // Wait if buffer full + if (IS_TX_FULL) { + // End Critical Section - need to let interrupt routine empty buffer by sending + NVIC_EnableIRQ(device_irqn); + //while (IS_TX_FULL) ; // buffer is full + tx_sem.wait(); + // Start Critical Section - don't interrupt while changing global buffer variables + NVIC_DisableIRQ(device_irqn); + } + tx_buffer[tx_in] = tx_line[i]; + i++; + tx_in = NEXT(tx_in); + } + if (Serial::writeable() && (empty)) { + temp_char = tx_buffer[tx_out]; + tx_out = NEXT(tx_out); + // Send first character to start tx interrupts, if stopped + LPC_UART1->THR = temp_char; + } + // End Critical Section + NVIC_EnableIRQ(device_irqn); +} + +// Read a line from the large rx buffer from rx interrupt routine +void BufferedSerial::read_line(char *c) +{ + int i; + i = 0; + // Start Critical Section - don't interrupt while changing global buffer variables + NVIC_DisableIRQ(device_irqn); + // Loop reading rx buffer characters until end of line character + while ((i==0) || (rx_line[i-1] != '\r')) { + // Wait if buffer empty + if (IS_RX_EMPTY) { // buffer empty + // End Critical Section - need to allow rx interrupt to get new characters for buffer + NVIC_EnableIRQ(device_irqn); + //while (rx_in == rx_out) ; // buffer empty + rx_sem.wait(); + // Start Critical Section - don't interrupt while changing global buffer variables + NVIC_DisableIRQ(device_irqn); + } else { + rx_sem.wait(); + } + rx_line[i] = rx_buffer[rx_out]; + i++; + rx_out = NEXT(rx_out); + + } + rx_line[i-1] = 0; + // End Critical Section + NVIC_EnableIRQ(device_irqn); + strncpy(c,rx_line,LINE_SIZE); +} + +// Interupt Routine to read in data from serial port +void BufferedSerial::Rx_interrupt() +{ + uint32_t IRR1 = LPC_UART1->IIR; + led1=1; + while (readable() && !(IS_RX_FULL)) { + rx_buffer[rx_in] = LPC_UART1->RBR; + rx_in = NEXT(rx_in); + rx_sem.release(); + } + led1=0; +} + +// Interupt Routine to write out data to serial port +void BufferedSerial::Tx_interrupt() +{ + uint32_t IRR = LPC_UART1->IIR; + led2=1; + while ((writeable()) && (tx_in != tx_out)) { // while serial is writeable and there are still characters in the buffer + LPC_UART1->THR = tx_buffer[tx_out]; // send the character + tx_out = NEXT(tx_out); + } + if(!IS_TX_FULL) // if not full + tx_sem.release(); + led2=0; +} \ No newline at end of file