Sam Grove
Inherit from Serial and use software buffers for TX and RX. This allows the UART peripherals to operate in a IRQ driven mode. Overrides most (but not all) stdio functions as Serial did
Dependents: buffered_serial_test BLE_Police_HRM evena_BLE_Police_HRM df-2014-workshop-rfid-case-generator-k64f ... more
Example
#include "mbed.h"
#include "BufferedSerial.h"
BufferedSerial pc(USBTX, USBRX);
int main()
{
pc.baud(115200);
while(1)
{
Timer s;
s.start();
pc.printf("Hello World - buff\n");
int buffered_time = s.read_us();
wait(0.1f); // give time for the buffer to empty
s.reset();
printf("Hello World - poll\n");
int polled_time = s.read_us();
s.stop();
wait(0.1f); // give time for the buffer to empty
pc.printf("printf buffered took %d us\n", buffered_time);
pc.printf("printf polled took %d us\n", polled_time);
wait(0.5f);
}
}
Revision 10:9ee15ae3d1a3, committed 2015-01-07
- Comitter:
- ansond
- Date:
- Wed Jan 07 18:37:11 2015 +0000
- Parent:
- 9:2cb30392ade6
- Child:
- 11:779304f9c5d2
- Commit message:
- updates to the constructor to enable expansion of the internal ring buffers and printf() buffer sizes
Changed in this revision
--- a/Buffer.lib Sun Jan 04 23:27:53 2015 +0000 +++ b/Buffer.lib Wed Jan 07 18:37:11 2015 +0000 @@ -1,1 +1,1 @@ -https://mbed.org/users/sam_grove/code/Buffer/#cd0a1f4c623f +https://mbed.org/users/sam_grove/code/Buffer/#7b754354b99c
--- a/BufferedSerial.cpp Sun Jan 04 23:27:53 2015 +0000
+++ b/BufferedSerial.cpp Wed Jan 07 18:37:11 2015 +0000
@@ -23,11 +23,12 @@
#include "BufferedSerial.h"
#include <stdarg.h>
-BufferedSerial::BufferedSerial(PinName tx, PinName rx, const char* name)
- : SERIAL_BASE(tx, rx) , _rxbuf(2*BUFFEREDSERIAL_MAX_BUFFER_SIZE), _txbuf(2*BUFFEREDSERIAL_MAX_BUFFER_SIZE)
+BufferedSerial::BufferedSerial(PinName tx, PinName rx, uint32_t buf_size, uint32_t tx_multiple, const char* name)
+ : SERIAL_BASE(tx, rx) , _rxbuf(buf_size), _txbuf((uint32_t)(tx_multiple*buf_size))
{
SERIAL_BASE::attach(this, &BufferedSerial::rxIrq, Serial::RxIrq);
-
+ this->_buf_size = buf_size;
+ this->_tx_multiple = tx_multiple;
return;
}
@@ -80,20 +81,21 @@
int BufferedSerial::printf(const char* format, ...)
{
- memset(this->_buffer,0,BUFFEREDSERIAL_MAX_BUFFER_SIZE+1);
+ char buffer[this->_buf_size];
+ memset(buffer,0,this->_buf_size);
int r = 0;
va_list arg;
va_start(arg, format);
- r = vsprintf(this->_buffer, format, arg);
+ r = vsprintf(buffer, format, arg);
// this may not hit the heap but should alert the user anyways
- if(r > BUFFEREDSERIAL_MAX_BUFFER_SIZE) {
- error("%s %d buffer overwrite (max_buf_size: %d exceeded: %d)!\r\n", __FILE__, __LINE__,BUFFEREDSERIAL_MAX_BUFFER_SIZE,r);
+ if(r > this->_buf_size) {
+ error("%s %d buffer overwrite (max_buf_size: %d exceeded: %d)!\r\n", __FILE__, __LINE__,this->_buf_size,r);
va_end(arg);
return 0;
}
va_end(arg);
- r = BufferedSerial::write(this->_buffer, r);
+ r = BufferedSerial::write(buffer, r);
return r;
}
--- a/BufferedSerial.h Sun Jan 04 23:27:53 2015 +0000
+++ b/BufferedSerial.h Wed Jan 07 18:37:11 2015 +0000
@@ -30,9 +30,6 @@
// Base Class
#define SERIAL_BASE RawSerial
-// Internal buffer size (Ring buffers will be 2X this value each for RX and TX...)
-#define BUFFEREDSERIAL_MAX_BUFFER_SIZE 512
-
/** A serial port (UART) for communication with other serial devices
*
* Can be used for Full Duplex communication, or Simplex by specifying
@@ -79,7 +76,8 @@
private:
Buffer <char> _rxbuf;
Buffer <char> _txbuf;
- char _buffer[BUFFEREDSERIAL_MAX_BUFFER_SIZE+1];
+ uint32_t _buf_size;
+ uint32_t _tx_multiple;
void rxIrq(void);
void txIrq(void);
@@ -89,10 +87,12 @@
/** Create a BufferedSerial port, connected to the specified transmit and receive pins
* @param tx Transmit pin
* @param rx Receive pin
+ * @param buf_size printf() buffer size
+ * @param tx_multiple amount of max printf() present in the internal ring buffer at one time
* @param name optional name
* @note Either tx or rx may be specified as NC if unused
*/
- BufferedSerial(PinName tx, PinName rx, const char* name=NULL);
+ BufferedSerial(PinName tx, PinName rx, uint32_t buf_size = 256, uint32_t tx_multiple = 4,const char* name=NULL);
/** Destroy a BufferedSerial port
*/
