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.
Diff: main.cpp
- 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++); + } + } +}