Revision 2:94d791a36afe, committed 2014-08-01

Comitter:

mosi

Date:

Fri Aug 01 21:54:31 2014 +0000

Parent:

1:ae55f51ee284

Child:

3:4ed0d32d3b38

Commit message:

Implemented serial read interrupt from another example, echoing of serial read and couple of comments;

Changed in this revision

--- a/main.cpp	Fri Sep 27 05:33:28 2013 +0000
+++ b/main.cpp	Fri Aug 01 21:54:31 2014 +0000
@@ -2,13 +2,37 @@
 #include "mbed_rpc.h"
 
 Serial pc(USBTX, USBRX);
+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];
+
+
 
 int main() {
+
     char buf[256], outbuf[256];
-
+    pc.baud(115200);
+    
     // setup the classes that can be created dynamically
-//    RPC::add_rpc_class<RpcAnalogIn>();
-//    RPC::add_rpc_class<RpcAnalogOut>();
+    //    RPC::add_rpc_class<RpcAnalogIn>();
+    //    RPC::add_rpc_class<RpcAnalogOut>();
     RPC::add_rpc_class<RpcDigitalIn>();
     RPC::add_rpc_class<RpcDigitalOut>();
     RPC::add_rpc_class<RpcDigitalInOut>();
@@ -18,9 +42,125 @@
     RPC::add_rpc_class<RpcSerial>();
 
     // receive commands, and send back the responses
+    pc.printf(" ************** Serial RPC example starting ************************* \r\n");
+    // Setup a serial interrupt function to receive data
+    pc.attach(&Rx_interrupt, Serial::RxIrq);
+    // Setup a serial interrupt function to transmit data
+    //pc.attach(&Tx_interrupt, Serial::TxIrq);
+    
+    
     while(1) {
-        pc.gets(buf, 256);
+        // Read a line from the large rx buffer from rx interrupt routine
+        read_line();
+            
+        //pc.gets(buf, 4);        
+        //pc.printf("#> '%s'\r\n", buf);
+        
+        /************************************
+        This is an example of the RPC command required to create an LED object and turn it on:
+        /DigitalOut/new LED1 myled
+        /myled/write 1
+        *************************************
+        */
+
+
         RPC::call(buf, outbuf); 
+        RPC::call(rx_line, outbuf); 
+
         pc.printf("%s\r\n", outbuf);
     }
 }
+
+
+
+// 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 (pc.writeable() && (empty)) {
+        temp_char = tx_buffer[tx_out];
+        tx_out = (tx_out + 1) % buffer_size;
+// Send first character to start tx interrupts, if stopped
+        pc.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;
+    }
+// End Critical Section
+    NVIC_EnableIRQ(UART1_IRQn);
+    rx_line[i-1] = 0;
+    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 ((pc.readable()) && (((rx_in + 1) % buffer_size) != rx_out)) {
+        rx_buffer[rx_in] = pc.getc();
+// Uncomment to Echo to USB serial to watch data flow
+        pc.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 ((pc.writeable()) && (tx_in != tx_out)) {
+        pc.putc(tx_buffer[tx_out]);
+        tx_out = (tx_out + 1) % buffer_size;
+    }
+//    led2=0;
+    return;
+}

--- a/mbed.bld	Fri Sep 27 05:33:28 2013 +0000
+++ b/mbed.bld	Fri Aug 01 21:54:31 2014 +0000
@@ -1,1 +1,1 @@
-http://mbed.org/users/mbed_official/code/mbed/builds/a9913a65894f
\ No newline at end of file
+http://mbed.org/users/mbed_official/code/mbed/builds/6213f644d804
\ No newline at end of file