Tom Soulanille
An RTOS-friendly Serial interface Its primary benefit is that it never hogs the CPU. An amusing alternative to the traditional ring-bufferd interrupt-serviced systems, it uses short mbed-rtos queues to buffer characters to and from the UART, and a thread to service the transmitter. Short interrupt service routines enqueue received characters and signal the transmit thread when the transmitter is available. WARNING: Do not create RTOS-Serial objects before the RTOS is running! Put them inside your main() block or another function, not in the global initialization.
Dependents: Test_RDM880_rfid_reader
Diff: rtos_serial.cpp
- Revision:
- 11:bc067b42f8e0
- Parent:
- 10:d5adca63e94a
- Child:
- 12:be7883573c91
--- a/rtos_serial.cpp Wed Oct 23 21:06:59 2013 +0000
+++ b/rtos_serial.cpp Thu Oct 24 05:34:47 2013 +0000
@@ -21,8 +21,6 @@
*/
/* TODO:
- * - assert rx overrun failure
- * - fix rx overrun failure
* - size the tx thread stack
* - make an rx buffer thread
* - implement readable()
@@ -37,7 +35,8 @@
const PinName leds[] = {LED1,LED2,LED3,LED4};
ledp = new DigitalOut(leds[uart_number]);
#ifdef RTOS_SERIAL_TX_THREAD
- tx_emitter_threadp = new Thread(tx_emitter, (void *) this);
+ tx_emitter_threadp = new Thread(tx_emitter, (void *) this,
+ osPriorityNormal, RTOS_SERIAL_TX_THREAD_STACK_SIZE);
#endif
// rx_isr_pFP = attach(this, &RTOS_Serial::rx_isr, RxIrq);
// tx_isr_pFP = attach(this, &RTOS_Serial::tx_isr, TxIrq);
@@ -75,6 +74,8 @@
int RTOS_Serial::get_index() { return _serial.index; }
+int RTOS_Serial::get_baud() { return _baud; }
+
int RTOS_Serial::putc(int c) {
//return Serial::putc(c); //DEBUG
//if (tx_q.put((int *)c, osWaitForever) == osOK) return c; else return EOF;
@@ -116,7 +117,7 @@
}
void RTOS_Serial::rx_isr(){
- rx_q.put((int *) _getc()); // FIXME: won't this wedge on overrun?
+ rx_q.put((int *) _getc()); // returns immediately even if queue was full
}
void RTOS_Serial::tx_isr(){