NucleoF401RE - XBee serial RX/TX with FIFO buffer. RX: Interrupt - FIFO buffering. TX: FIFO buffering - polling (tx_buffer empty). In this program, received data (7bytes format ([000000-7FFFFF]+13(cr)]) is merged to auto-increment message to transfer.

Dependencies:   mbed

Revision:
0:0d80708af8ce
diff -r 000000000000 -r 0d80708af8ce main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Dec 06 04:31:53 2014 +0000
@@ -0,0 +1,89 @@
+#include "mbed.h"
+
+unsigned char rxFIFO[256], txFIFO[256], raw_data[6];
+unsigned char rx_top, rx_end, tx_top, tx_end, phase;
+
+RawSerial xbee(PA_2, PA_3);
+DigitalOut myled(LED1);
+
+void tx_fifo_check(){
+    if(xbee.writeable() == 1){
+        if(tx_top != tx_end){
+            xbee.putc(txFIFO[tx_end]);
+            ++tx_end &= 255;
+        }
+    }
+    return;
+}
+
+int rx_fifo_check(){
+    unsigned char data;
+    if(rx_top != rx_end){
+        data = rxFIFO[rx_end];
+        ++rx_end &= 255;
+        if (data < 33){
+            phase = 0;
+            return(1);
+        }
+        raw_data[phase] = data;
+        if(++phase > 5) phase = 0;
+        return(0);
+    }
+    return(0);
+}
+
+void rx_fifoset(void){
+    rxFIFO[rx_top] = xbee.getc();
+    ++rx_top &= 255;
+    return;
+}
+
+void tx_fifoset(unsigned char data){
+    txFIFO[tx_top] = data;
+    ++tx_top &= 255;
+    return;
+}
+
+unsigned char hex_conv(unsigned char data){
+    data &= 15;
+    if(data < 10) return(data+48);
+    else return(data+55);
+}
+
+unsigned char conv_hex(unsigned char data){
+    if((data > 47) && (data < 58)) return(data-48);
+    else if((data > 64) && (data < 71)) return(data-55);
+    return(0);
+}
+
+void tx_message(int data){
+    int i;
+    for (i=0; i<6; i++){
+        tx_fifoset(hex_conv((data>>(4*(5-i))) & 15));
+    }
+    tx_fifoset(13);
+}
+
+int main(){
+    int i, j, k, sum;
+    i = j = k = 0;
+    rx_top = rx_end = tx_top = tx_end = phase = 0; 
+    xbee.baud(38400);
+    xbee.attach(&rx_fifoset, xbee.RxIrq);
+    while(1){
+        tx_fifo_check();
+        if(rx_fifo_check() == 1){
+            sum = 0;
+            for (i=0; i<6; i++){
+                sum += conv_hex(raw_data[i])<<(4*(5-i));
+            }
+            tx_message(sum); /* Echo Back */
+        }
+        if(++j > 1000000){
+            j = 0;
+            myled = !myled;
+            k &= 8388607;
+            tx_message(k++);
+        }
+    }
+}