Revision 0:023c5cda6102, committed 2010-11-16

Comitter:

4180_1

Date:

Tue Nov 16 15:00:30 2010 +0000

Child:

1:2f1e54d137c7

Commit message:

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Nov 16 15:00:30 2010 +0000
@@ -0,0 +1,181 @@
+
+#include "mbed.h"
+// Serial TX & RX interrupt loopback test using formatted IO - sprintf and sscanf
+// Connect TX to RX (p9 to p10)
+// or can also use USB and type back in the number printed out in a terminal window
+// Sends out ASCII numbers in a loop and reads them back
+// If not the same number LED4 goes on
+// LED1 and LED2 indicate RX and TX interrupt routine activity
+// LED3 changing indicate main loop running
+
+
+Serial device(p9, p10);  // tx, rx
+// Can also use USB and type back in the number printed out in a terminal window
+// Serial monitor_device(USBTX, USBRX);
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+DigitalOut led3(LED3);
+DigitalOut led4(LED4);
+
+
+void Tx_interrupt();
+void Rx_interrupt();
+void send_line();
+void read_line();
+
+
+// Circular buffers for serial TX and RX data - used by interrupt routines
+const int buffer_size = 255;
+// might need to increase buffer size for high baud rates
+char tx_buffer[buffer_size];
+char rx_buffer[buffer_size];
+// Circular buffer pointers
+// volatile makes read-modify-write atomic
+volatile int tx_in=0;
+volatile int tx_out=0;
+volatile int rx_in=0;
+volatile int rx_out=0;
+// Line buffers for sprintf and sscanf
+char tx_line[80];
+char rx_line[80];
+
+// main test program
+int main() {
+    int i=0;
+    int rx_i=0;
+    device.baud(9600);
+
+// Setup a serial interrupt function to receive data
+    device.attach(&Rx_interrupt, Serial::RxIrq);
+// Setup a serial interrupt function to transmit data
+    device.attach(&Tx_interrupt, Serial::TxIrq);
+
+// Formatted IO test using send and receive serial interrupts
+// with sprintf and sscanf
+    while (1) {
+// Loop to generate different test values - send value in hex, decimal, and octal and  then read back
+        for (i=0; i<0xFFFF; i++) {
+            led3=1;
+// Print ASCII number to tx line buffer in hex
+            sprintf(tx_line,"%x\r\n",i);
+// Copy tx line buffer to large tx buffer for tx interrupt routine
+            send_line();
+// Print ASCII number to tx line buffer in decimal
+            sprintf(tx_line,"%d\r\n",i);
+// Copy tx line buffer to large tx buffer for tx interrupt routine
+            send_line();
+// Print ASCII number to tx line buffer in octal
+            sprintf(tx_line,"%o\r\n",i);
+// Copy tx line buffer to large tx buffer for tx interrupt routine
+            send_line();
+            led3=0;
+// Read a line from the large rx buffer from rx interrupt routine
+            read_line();
+// Read ASCII number from rx line buffer
+            sscanf(rx_line,"%x",&rx_i);
+// Check that numbers are the same
+            if (i != rx_i) led4=1;
+// Read a line from the large rx buffer from rx interrupt routine
+            read_line();
+// Read ASCII number from rx line buffer
+            sscanf(rx_line,"%d",&rx_i);
+// Check that numbers are the same
+            if (i != rx_i) led4=1;
+// Read a line from the large rx buffer from rx interrupt routine
+            read_line();
+// Read ASCII number from rx line buffer
+            sscanf(rx_line,"%o",&rx_i);
+// Check that numbers are the same
+            if (i != rx_i) led4=1;
+        }
+    }
+}
+
+// Copy tx line buffer to large tx buffer for tx interrupt routine
+void send_line() {
+    int i;
+    char temp_char;
+    bool empty;
+    i = 0;
+// Start Critical Section - don't interrupt while changing global buffer variables
+    NVIC_DisableIRQ(UART1_IRQn);
+    empty = (tx_in == tx_out);
+    while ((i==0) || (tx_line[i-1] != '\n')) {
+// Wait if buffer full
+        if (((tx_in + 1) % buffer_size) == tx_out) {
+// End Critical Section - need to let interrupt routine empty buffer by sending
+            NVIC_EnableIRQ(UART1_IRQn);
+            while (((tx_in + 1) % buffer_size) == tx_out) {
+            }
+// Start Critical Section - don't interrupt while changing global buffer variables
+            NVIC_DisableIRQ(UART1_IRQn);
+        }
+        tx_buffer[tx_in] = tx_line[i];
+        i++;
+        tx_in = (tx_in + 1) % buffer_size;
+    }
+    if (device.writeable() && (empty)) {
+        temp_char = tx_buffer[tx_out];
+        tx_out = (tx_out + 1) % buffer_size;
+// Send first character to start tx interrupts, if stopped
+        device.putc(temp_char);
+    }
+// End Critical Section
+    NVIC_EnableIRQ(UART1_IRQn);
+    return;
+}
+
+// Read a line from the large rx buffer from rx interrupt routine
+void read_line() {
+    int i;
+    i = 0;
+// Start Critical Section - don't interrupt while changing global buffer variables
+    NVIC_DisableIRQ(UART1_IRQn);
+// Loop reading rx buffer characters until end of line character
+    while ((i==0) || (rx_line[i-1] != '\r')) {
+// Wait if buffer empty
+        if (rx_in == rx_out) {
+// End Critical Section - need to allow rx interrupt to get new characters for buffer
+            NVIC_EnableIRQ(UART1_IRQn);
+            while (rx_in == rx_out) {
+            }
+// Start Critical Section - don't interrupt while changing global buffer variables
+            NVIC_DisableIRQ(UART1_IRQn);
+        }
+        rx_line[i] = rx_buffer[rx_out];
+        i++;
+        rx_out = (rx_out + 1) % buffer_size;
+    }
+    rx_line[i-1] = 0;
+// End Critical Section
+    NVIC_EnableIRQ(UART1_IRQn);
+    return;
+}
+
+// Interupt Routine to read in data from serial port
+void Rx_interrupt() {
+    led1=1;
+// Loop just in case more than one character is in UART's receive FIFO buffer
+// Stop if buffer full
+    while ((device.readable()) || (((rx_in + 1) % buffer_size) == rx_out)) {
+        rx_buffer[rx_in] = device.getc();
+// Uncomment to Echo to USB serial to watch data flow
+//        monitor_device.putc(rx_buffer[rx_in]);
+        rx_in = (rx_in + 1) % buffer_size;
+    }
+    led1=0;
+    return;
+}
+
+// Interupt Routine to write out data to serial port
+void Tx_interrupt() {
+    led2=1;
+// Loop to fill more than one character in UART's transmit FIFO buffer
+// Stop if buffer empty
+    while ((device.writeable()) && (tx_in != tx_out)) {
+        device.putc(tx_buffer[tx_out]);
+        tx_out = (tx_out + 1) % buffer_size;
+    }
+    led2=0;
+    return;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Tue Nov 16 15:00:30 2010 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/e2ac27c8e93e